Release v0.4.4

.gitignore

@@ -1,7 +1,6 @@
 __pycache__/
 *.py[cod]
 junk/
-.vscode
 .ipynb_checkpoints/
 tools/ansible/inventory/hawaii.yml
 tools/ansible/inventory/peppermint.yml
@@ -17,6 +16,7 @@ dist/
 *.egg-info/
 .venv/
 venv/
+docs/_build/
 .codex
 
 

.vscode/extensions.json

@@ -0,0 +1,11 @@
+{
+  "recommendations": [
+    "swyddfa.esbonio",
+    "ms-python.python",
+    "ms-python.vscode-pylance",
+    "ms-python.debugpy",
+    "tamasfe.even-better-toml",
+    "redhat.vscode-yaml",
+    "DavidAnson.vscode-markdownlint"
+  ]
+}

.vscode/settings.json

@@ -0,0 +1,18 @@
+{
+  "esbonio.sphinx.pythonCommand": "${venv:.venv}/bin/python",
+  "esbonio.sphinx.buildCommand": [
+    "sphinx-build",
+    "-b",
+    "html",
+    "docs",
+    "docs/_build/html"
+  ],
+  "python.defaultInterpreterPath": "${workspaceFolder}/.venv/bin/python",
+  "python.testing.pytestEnabled": true,
+  "python.testing.pytestArgs": [
+    "--ignore=tests/legacy",
+    "--ignore=tests/support",
+    "tests"
+  ],
+  "restructuredtext.confPath": "${workspaceFolder}/docs"
+}

README.md

@@ -99,95 +99,4 @@ TMDB-backed metadata enrichment requires `TMDB_API_KEY` to be set in the environ
 
 ## Version History
 
-### 0.4.2
-
-- pattern details now show an inline `Show: <quality>` hint next to the quality field when the pattern itself has no stored quality but the selected show does
-- inspect stream tables now show attachment format labels like `TTF` in the codec column and keep attachment language cells blank instead of showing an undefined language
-- ffmpeg damaged-MP3 diagnostics now recognize additional corruption lines such as `invalid new backstep`, keeping them grouped under the `warn-corrupt-mpeg-audio` review summary
-
-### 0.4.1
-
-- `convert` now supports `--copy-video` and `--copy-audio` to keep the selected stream type in copy mode without applying the corresponding reencode flags, filters, or formatting options
-- ffmpeg conversions now monitor diagnostics while the process is running, retry unset AVI packet timestamps once with `-fflags +genpts`, and stop early when a file should be skipped instead of waiting for the full job to finish
-- end-of-run convert summaries now list only ffmpeg findings that still require review, including named remedy identifiers such as `warn-corrupt-mpeg-audio`
-- `upgrade` now finishes by reporting the installed FFX version together with the active bundle branch
-
-### 0.3.1
-
-- debug mode screen titles now append the active Textual screen class name, making screen-specific troubleshooting easier during inspect and edit flows
-- `--cut` again works as a combined flag/option: omitted disables cutting, bare `--cut` applies the default `60,180`, and explicit duration or `START,DURATION` values stay supported
-- H.265 unmux commands no longer force an invalid `-f h265` output format, keeping ffmpeg copy extraction aligned with the required Annex B bitstream filter
-- H.264 encoding now falls back from `libx264` to `libopenh264` with a warning when needed, and the test fixtures use the same encoder fallback so the suite remains portable across ffmpeg builds
-
-### 0.3.0
-
-- inspect and edit screens now refresh nested track and pattern changes more reliably, with inspect-mode tables aligned to the target pattern view shown in the differences pane
-- metadata editing got a follow-up polish pass with clearer ffmpeg notifications, a shared in-screen log pane, safer apply/reload handling, and expanded cleanup and normalization coverage
-- track and asset probing recognize additional codecs, and the modern test suite now covers more metadata-editor, change-set, screen-state, and asset-probe behavior
-- Textual now requires version `8.0` or newer to match the UI APIs used by the current screens
-
-### 0.2.6
-
-- DB-free `ffx edit` workflow for in-place metadata editing via temporary-file rewrite
-- inspect and edit workflows split into dedicated Textual screens with shared media-workflow support
-- Textual tables and row actions now separate raw data from rendered labels to avoid markup leaking into stored metadata
-- responsive screen layout pass, `Esc` back handling, sortable show/inspect tables, and improved edit-screen notifications/toggles
-- application-wide UTF-8 i18n catalogs with language precedence from CLI over config over system over German default
-- metadata normalization extended for localized subtitle titles, ISO language cleanup, and smarter track editor language/title helpers
-
-### 0.2.5
-
-- show-level quality and notes fields
-- pattern-over-show-over-default season-shift resolution with dynamic DB migration loading
-- migration prompt now reports the upgrade path and creates an in-place DB backup before applying schema changes
-- `upgrade --branch <name>` now fetches remote-only branches before switching
-- `unmux` now applies season shifting to subtitle output filenames
-- convert now keeps DB-defined target subtitle dispositions authoritative over sidecar filename disposition flags when a pattern definition exists
-- focused modern tests added around migrations, unmux, upgrade, and subtitle-disposition import precedence
-
-### 0.2.4
-
-- lightweight CLI commands now stay import-light via lazy runtime loading
-- setup/config templating moved to `assets/ffx.json.j2`
-- aligned two-step local setup wrappers: `ffx setup` and `ffx configure_workstation`
-- combined `ffprobe` payload reuse in `FileProperties`
-- configurable crop-detect sampling plus per-process crop result caching
-- single-query controller accessors and conditional DB schema bootstrap
-- shared screen bootstrap/controller wiring for large detail screens
-- configurable default season/episode digit lengths
-- digit-aware `rename` and padded `unmux` filename markers
-
-### 0.2.3
-
-- PyPI packaging
-- output filename templating
-- season shifting
-- DB versioning
-
-### 0.2.2
-
-- CLI overrides
-
-### 0.2.1
-
-- signature handling
-- tag cleanup
-- bugfixes and refactoring
-
-### 0.2.0
-
-- tests
-- config file
-
-### 0.1.3
-
-- subtitle file imports
-
-### 0.1.2
-
-- bugfixes
-
-### 0.1.1
-
-- bugfixes
-- TMDB show identification
+See the [version history](docs/history.rst) for release notes.

docs/Makefile

@@ -0,0 +1,21 @@
+SPHINXOPTS       ?=
+VENV_SPHINXBUILD = ../.venv/bin/sphinx-build
+SPHINXBUILD      ?= $(if $(wildcard $(VENV_SPHINXBUILD)),$(VENV_SPHINXBUILD),sphinx-build)
+SOURCEDIR        = .
+BUILDDIR         = _build
+
+.PHONY: help clean html linkcheck
+
+help:
+	@echo "Please use 'make <target>' where <target> is one of"
+	@echo "  html       to make standalone HTML files"
+	@echo "  linkcheck  to check all external links for integrity"
+
+clean:
+	rm -rf "$(BUILDDIR)"
+
+html:
+	@$(SPHINXBUILD) -b html "$(SOURCEDIR)" "$(BUILDDIR)/html" $(SPHINXOPTS)
+
+linkcheck:
+	@$(SPHINXBUILD) -b linkcheck "$(SOURCEDIR)" "$(BUILDDIR)/linkcheck" $(SPHINXOPTS)

docs/api.rst

@@ -0,0 +1,31 @@
+API Reference
+=============
+
+This section exposes selected modules that are useful when working on tests,
+diagnostics, process execution, metadata editing, and file probing.
+
+CLI Helpers
+-----------
+
+.. automodule:: ffx.cli
+   :members:
+   :undoc-members:
+
+Process Helpers
+---------------
+
+.. automodule:: ffx.process
+   :members:
+   :undoc-members:
+
+File Probing
+------------
+
+.. automodule:: ffx.file_properties
+
+Metadata Editing
+----------------
+
+.. automodule:: ffx.metadata_editor
+   :members:
+   :undoc-members:

docs/conf.py

@@ -0,0 +1,44 @@
+from __future__ import annotations
+
+from importlib.metadata import PackageNotFoundError, version as package_version
+from pathlib import Path
+import sys
+
+
+ROOT_DIR = Path(__file__).resolve().parents[1]
+SRC_DIR = ROOT_DIR / "src"
+sys.path.insert(0, str(SRC_DIR))
+
+project = "FFX"
+author = "javanaut@maveno.de"
+copyright = "2026, Maveno"
+
+try:
+    release = package_version("ffx")
+except PackageNotFoundError:
+    release = "0.0.0"
+version = release
+
+extensions = [
+    "sphinx.ext.autodoc",
+    "sphinx.ext.napoleon",
+    "sphinx.ext.viewcode",
+    "sphinx_copybutton",
+]
+
+source_suffix = {
+    ".rst": "restructuredtext",
+}
+
+templates_path = ["_templates"]
+exclude_patterns = ["_build", "Thumbs.db", ".DS_Store"]
+
+html_theme = "sphinx_rtd_theme"
+html_title = "FFX"
+html_static_path = []
+
+autodoc_typehints = "description"
+autodoc_member_order = "bysource"
+napoleon_google_docstring = True
+napoleon_numpy_docstring = True
+

docs/development.rst

@@ -0,0 +1,50 @@
+Development
+===========
+
+The repo-local ``.venv`` is the preferred environment for contributors working
+on tests or documentation:
+
+.. code-block:: sh
+
+   tests/prepare.sh
+
+The preparation script installs the package in editable mode with both test and
+documentation extras:
+
+.. code-block:: text
+
+   .[test,docs]
+
+Run Tests
+---------
+
+Run the modern pytest suite:
+
+.. code-block:: sh
+
+   .venv/bin/python -m pytest --ignore=tests/legacy --ignore=tests/support tests
+
+The legacy harness remains available separately and is intentionally not part of
+the default pytest run.
+
+Build Docs
+----------
+
+Build HTML documentation:
+
+.. code-block:: sh
+
+   .venv/bin/sphinx-build -b html docs docs/_build/html
+
+The same command is wrapped by the Sphinx ``Makefile``:
+
+.. code-block:: sh
+
+   make -C docs html
+
+VS Code
+-------
+
+The repository includes ``.vscode/extensions.json`` with recommended
+extensions, including Esbonio for Sphinx language-server support. The workspace
+settings point Python tooling and Esbonio at the repo-local ``.venv``.

docs/file_formats.md

@@ -1,170 +0,0 @@
-# File Formats
-
-This document captures source-file-format notes that complement the normative
-requirements in `requirements/source_file_formats.md`.
-
-The first documented format is a Matroska source that carries styled ASS/SSA
-subtitle streams together with embedded font attachments.
-
-## Styled ASS In Matroska With Embedded Fonts
-
-These files are typically `.mkv` releases where subtitle rendering quality
-depends on keeping both parts of the subtitle package together:
-
-- one or more subtitle streams with codec `ass`
-- one or more attachment streams that embed font files used by those subtitles
-
-This matters because ASS subtitles are not plain text subtitles in the narrow
-WebVTT sense. They can carry layout, styling, positioning, karaoke, signs, and
-other typesetting effects. If the matching embedded fonts are lost, consumers
-can still see subtitle text but the intended styling and sometimes glyph
-coverage can be degraded.
-
-For FFX this format is special because the ASS subtitle streams should remain
-normally editable and mappable, while the related font attachments should be
-transported unchanged.
-
-## Observed Sample
-
-Assessment date: `2026-04-17`
-
-Observed sample file:
-
-- `tests/assets/boruto_s01e283_ssa.mkv`
-
-Commands used for assessment:
-
-```bash
-ffprobe tests/assets/boruto_s01e283_ssa.mkv
-ffprobe -hide_banner -show_format -show_streams -of json tests/assets/boruto_s01e283_ssa.mkv
-```
-
-Observed stream layout:
-
-| Stream index | Kind | Key details |
-| --- | --- | --- |
-| `0` | video | `codec_name=h264` |
-| `1` | audio | `codec_name=aac`, `language=jpn` |
-| `2` | subtitle | `codec_name=ass`, `language=ger`, default |
-| `3` | subtitle | `codec_name=ass`, `language=eng` |
-| `4`-`13` | attachment | `tags.mimetype=font/ttf`, `.ttf` filenames |
-
-Observed attachment filenames:
-
-- `AmazonEmberTanuki-Italic.ttf`
-- `AmazonEmberTanuki-Regular.ttf`
-- `Arial.ttf`
-- `Arial Bold.ttf`
-- `Georgia.ttf`
-- `Times New Roman.ttf`
-- `Times New Roman Bold.ttf`
-- `Trebuchet MS.ttf`
-- `Verdana.ttf`
-- `Verdana Bold.ttf`
-
-Important probe behavior from the real sample:
-
-- Plain `ffprobe` lists the font streams as `Attachment: none`.
-- Plain `ffprobe` also prints warnings such as `Could not find codec
-  parameters for stream 4 (Attachment: none): unknown codec` and later
-  `Unsupported codec with id 0 for input stream ...`.
-- The JSON produced by `FileProperties.FFPROBE_COMMAND_TOKENS`
-  (`ffprobe -hide_banner -show_format -show_streams -of json`) still exposes
-  the attachment streams clearly through `codec_type="attachment"` and the
-  attachment tags.
-- In that JSON, the attachment streams do not expose `codec_name`.
-
-This last point is important for FFX: robust detection must not depend on
-attachment `codec_name` being present.
-
-## Detection Guidance
-
-Current known indicators for this format are:
-
-- one or more subtitle streams with `codec_type="subtitle"` and
-  `codec_name="ass"`
-- one or more attachment streams with `codec_type="attachment"`
-- attachment tags that identify embedded fonts, especially
-  `tags.mimetype="font/ttf"`
-- attachment filenames that end in `.ttf`
-
-The pattern can vary. FFX should therefore treat the above as a cluster of
-signals rather than an exact signature tied to one file.
-
-Inference from the observed sample plus FFmpeg documentation:
-
-- MIME matching should not be limited to `font/ttf` alone.
-- The Boruto sample uses `font/ttf`.
-- FFmpeg's Matroska attachment example uses
-  `mimetype=application/x-truetype-font` for a `.ttf` attachment.
-- Detection should therefore normalize multiple TTF-like MIME values rather
-  than depend on a single exact string.
-
-## Processing Expectations In FFX
-
-The format-specific requirements live in
-`requirements/source_file_formats.md`. In practical terms, FFX should:
-
-- recognize the ASS-plus-font-attachment pattern even when attachment probe
-  data is incomplete
-- tell the operator that the pattern was detected and that special handling is
-  being used
-- reject sidecar subtitle import for such sources, because converting or
-  replacing these subtitle tracks with ordinary external text subtitles would
-  break the intended subtitle package
-- continue to allow normal manipulation of the ASS subtitle tracks themselves
-- preserve the font attachment streams unchanged
-
-## FFmpeg Notes
-
-Relevant FFmpeg documentation confirms several behaviors that line up with
-FFX's needs:
-
-- FFmpeg documents `-attach` as adding an attachment stream to the output, and
-  explicitly names Matroska fonts used in subtitle rendering as an example.
-- FFmpeg documents attachment streams as regular streams that are created after
-  the mapped media streams.
-- FFmpeg documents `-dump_attachment` for extracting attachment streams, which
-  is useful for debugging or validating a source file's embedded fonts.
-- FFmpeg's Matroska example requires a `mimetype` metadata tag for attached
-  fonts, which is consistent with using attachment tags as detection signals.
-- FFmpeg also notes that attachments are implemented as codec extradata. That
-  helps explain why probe output for attachment streams can look different from
-  ordinary audio, video, and subtitle streams.
-
-Implication for FFX:
-
-- Attachment preservation is not an optional cosmetic feature for this format.
-  It is part of preserving the subtitle package correctly.
-
-## Jellyfin Notes
-
-Jellyfin's documentation also supports keeping this format intact:
-
-- Jellyfin's subtitle compatibility table lists `ASS/SSA` as supported in
-  `MKV` and not supported in `MP4`.
-- Jellyfin notes that when subtitles must be transcoded, they are either
-  converted to a supported format or burned into the video, and burning them in
-  is the most CPU-intensive path.
-- Jellyfin's subtitle-extraction example for `SSA/ASS` first dumps attachment
-  streams and then extracts the ASS subtitle stream, which reflects the real
-  relationship between ASS subtitles and embedded fonts in MKV releases.
-- Jellyfin's font documentation says text-based subtitles require fonts to
-  render properly.
-- Jellyfin's configuration documentation says the web client uses configured
-  fallback fonts for ASS subtitles when other fonts such as MKV attachments or
-  client-side fonts are not available.
-
-Inference from the Jellyfin compatibility tables:
-
-- Keeping this subtitle format in Matroska is the safest interoperability
-  choice for Jellyfin consumers.
-- Converting the subtitle payload to WebVTT would lose styled ASS behavior.
-- Dropping the attachment streams would force client or fallback font
-  substitution and can change appearance or glyph coverage.
-
-## References
-
-- FFmpeg documentation: https://ffmpeg.org/ffmpeg.html
-- Jellyfin codec support: https://jellyfin.org/docs/general/clients/codec-support/
-- Jellyfin configuration and fonts: https://jellyfin.org/docs/general/administration/configuration/

docs/file_formats.rst

@@ -0,0 +1,192 @@
+File Formats
+============
+
+This document captures source-file-format notes that complement the normative
+requirements in ``requirements/source_file_formats.md``.
+
+The first documented format is a Matroska source that carries styled ASS/SSA
+subtitle streams together with embedded font attachments.
+
+Styled ASS In Matroska With Embedded Fonts
+------------------------------------------
+
+These files are typically ``.mkv`` releases where subtitle rendering quality
+depends on keeping both parts of the subtitle package together:
+
+* one or more subtitle streams with codec ``ass``
+* one or more attachment streams that embed font files used by those subtitles
+
+This matters because ASS subtitles are not plain text subtitles in the narrow
+WebVTT sense. They can carry layout, styling, positioning, karaoke, signs, and
+other typesetting effects. If the matching embedded fonts are lost, consumers
+can still see subtitle text but the intended styling and sometimes glyph
+coverage can be degraded.
+
+For FFX this format is special because the ASS subtitle streams should remain
+normally editable and mappable, while the related font attachments should be
+transported unchanged.
+
+Observed Sample
+---------------
+
+Assessment date: ``2026-04-17``
+
+Observed sample file:
+
+* ``tests/assets/boruto_s01e283_ssa.mkv``
+
+Commands used for assessment:
+
+.. code-block:: bash
+
+   ffprobe tests/assets/boruto_s01e283_ssa.mkv
+   ffprobe -hide_banner -show_format -show_streams -of json tests/assets/boruto_s01e283_ssa.mkv
+
+Observed stream layout:
+
+.. list-table::
+   :header-rows: 1
+
+   * - Stream index
+     - Kind
+     - Key details
+   * - ``0``
+     - video
+     - ``codec_name=h264``
+   * - ``1``
+     - audio
+     - ``codec_name=aac``, ``language=jpn``
+   * - ``2``
+     - subtitle
+     - ``codec_name=ass``, ``language=ger``, default
+   * - ``3``
+     - subtitle
+     - ``codec_name=ass``, ``language=eng``
+   * - ``4``-``13``
+     - attachment
+     - ``tags.mimetype=font/ttf``, ``.ttf`` filenames
+
+Observed attachment filenames:
+
+* ``AmazonEmberTanuki-Italic.ttf``
+* ``AmazonEmberTanuki-Regular.ttf``
+* ``Arial.ttf``
+* ``Arial Bold.ttf``
+* ``Georgia.ttf``
+* ``Times New Roman.ttf``
+* ``Times New Roman Bold.ttf``
+* ``Trebuchet MS.ttf``
+* ``Verdana.ttf``
+* ``Verdana Bold.ttf``
+
+Important probe behavior from the real sample:
+
+* Plain ``ffprobe`` lists the font streams as ``Attachment: none``.
+* Plain ``ffprobe`` also prints warnings such as ``Could not find codec
+  parameters for stream 4 (Attachment: none): unknown codec`` and later
+  ``Unsupported codec with id 0 for input stream ...``.
+* The JSON produced by ``FileProperties.FFPROBE_COMMAND_TOKENS``
+  (``ffprobe -hide_banner -show_format -show_streams -of json``) still exposes
+  the attachment streams clearly through ``codec_type="attachment"`` and the
+  attachment tags.
+* In that JSON, the attachment streams do not expose ``codec_name``.
+
+This last point is important for FFX: robust detection must not depend on
+attachment ``codec_name`` being present.
+
+Detection Guidance
+------------------
+
+Current known indicators for this format are:
+
+* one or more subtitle streams with ``codec_type="subtitle"`` and
+  ``codec_name="ass"``
+* one or more attachment streams with ``codec_type="attachment"``
+* attachment tags that identify embedded fonts, especially
+  ``tags.mimetype="font/ttf"``
+* attachment filenames that end in ``.ttf``
+
+The pattern can vary. FFX should therefore treat the above as a cluster of
+signals rather than an exact signature tied to one file.
+
+Inference from the observed sample plus FFmpeg documentation:
+
+* MIME matching should not be limited to ``font/ttf`` alone.
+* The Boruto sample uses ``font/ttf``.
+* FFmpeg's Matroska attachment example uses
+  ``mimetype=application/x-truetype-font`` for a ``.ttf`` attachment.
+* Detection should therefore normalize multiple TTF-like MIME values rather
+  than depend on a single exact string.
+
+Processing Expectations In FFX
+------------------------------
+
+The format-specific requirements live in
+``requirements/source_file_formats.md``. In practical terms, FFX should:
+
+* recognize the ASS-plus-font-attachment pattern even when attachment probe data
+  is incomplete
+* tell the operator that the pattern was detected and that special handling is
+  being used
+* reject sidecar subtitle import for such sources, because converting or
+  replacing these subtitle tracks with ordinary external text subtitles would
+  break the intended subtitle package
+* continue to allow normal manipulation of the ASS subtitle tracks themselves
+* preserve the font attachment streams unchanged
+
+FFmpeg Notes
+------------
+
+Relevant FFmpeg documentation confirms several behaviors that line up with
+FFX's needs:
+
+* FFmpeg documents ``-attach`` as adding an attachment stream to the output, and
+  explicitly names Matroska fonts used in subtitle rendering as an example.
+* FFmpeg documents attachment streams as regular streams that are created after
+  the mapped media streams.
+* FFmpeg documents ``-dump_attachment`` for extracting attachment streams, which
+  is useful for debugging or validating a source file's embedded fonts.
+* FFmpeg's Matroska example requires a ``mimetype`` metadata tag for attached
+  fonts, which is consistent with using attachment tags as detection signals.
+* FFmpeg also notes that attachments are implemented as codec extradata. That
+  helps explain why probe output for attachment streams can look different from
+  ordinary audio, video, and subtitle streams.
+
+Implication for FFX:
+
+* Attachment preservation is not an optional cosmetic feature for this format.
+  It is part of preserving the subtitle package correctly.
+
+Jellyfin Notes
+--------------
+
+Jellyfin's documentation also supports keeping this format intact:
+
+* Jellyfin's subtitle compatibility table lists ``ASS/SSA`` as supported in
+  ``MKV`` and not supported in ``MP4``.
+* Jellyfin notes that when subtitles must be transcoded, they are either
+  converted to a supported format or burned into the video, and burning them in
+  is the most CPU-intensive path.
+* Jellyfin's subtitle-extraction example for ``SSA/ASS`` first dumps attachment
+  streams and then extracts the ASS subtitle stream, which reflects the real
+  relationship between ASS subtitles and embedded fonts in MKV releases.
+* Jellyfin's font documentation says text-based subtitles require fonts to
+  render properly.
+* Jellyfin's configuration documentation says the web client uses configured
+  fallback fonts for ASS subtitles when other fonts such as MKV attachments or
+  client-side fonts are not available.
+
+Inference from the Jellyfin compatibility tables:
+
+* Keeping this subtitle format in Matroska is the safest interoperability choice
+  for Jellyfin consumers.
+* Converting the subtitle payload to WebVTT would lose styled ASS behavior.
+* Dropping the attachment streams would force client or fallback font
+  substitution and can change appearance or glyph coverage.
+
+References
+----------
+
+* FFmpeg documentation: https://ffmpeg.org/ffmpeg.html
+* Jellyfin codec support: https://jellyfin.org/docs/general/clients/codec-support/
+* Jellyfin configuration and fonts: https://jellyfin.org/docs/general/administration/configuration/

docs/history.rst

@@ -0,0 +1,123 @@
+Version History
+===============
+
+0.4.4
+-----
+
+- External subtitle imports can now match prefixless sidecar files against the source basename, choose their extension, and confirm partial substitutions.
+- Unmux now creates missing output directories with confirmation or the new ``--yes`` option.
+- Project documentation is now built with Sphinx and includes installation, usage, development, file-format, and API references.
+
+0.4.3
+-----
+
+- Styled ASS subtitle sources with embedded font attachments are now detected explicitly, keep MKV output, preserve current source font attachments, and reject incompatible sidecar subtitle import.
+- Attachment descriptors are now treated as source-runtime data instead of pattern schema data, so pattern persistence skips them and source-vs-pattern validation ignores them.
+- Inspect differences no longer report planned changes for attachment filename/count drift while still showing attachment streams in the stream table.
+
+0.4.2
+-----
+
+- Pattern details now show an inline ``Show: <quality>`` hint next to the quality field when the pattern itself has no stored quality but the selected show does.
+- Inspect stream tables now show attachment format labels like ``TTF`` in the codec column and keep attachment language cells blank instead of showing an undefined language.
+- FFmpeg damaged-MP3 diagnostics now recognize additional corruption lines such as ``invalid new backstep``, keeping them grouped under the ``warn-corrupt-mpeg-audio`` review summary.
+
+0.4.1
+-----
+
+- ``convert`` now supports ``--copy-video`` and ``--copy-audio`` to keep the selected stream type in copy mode without applying the corresponding reencode flags, filters, or formatting options.
+- FFmpeg conversions now monitor diagnostics while the process is running, retry unset AVI packet timestamps once with ``-fflags +genpts``, and stop early when a file should be skipped instead of waiting for the full job to finish.
+- End-of-run convert summaries now list only FFmpeg findings that still require review, including named remedy identifiers such as ``warn-corrupt-mpeg-audio``.
+- ``upgrade`` now finishes by reporting the installed FFX version together with the active bundle branch.
+
+0.3.1
+-----
+
+- Debug mode screen titles now append the active Textual screen class name, making screen-specific troubleshooting easier during inspect and edit flows.
+- ``--cut`` again works as a combined flag/option: omitted disables cutting, bare ``--cut`` applies the default ``60,180``, and explicit duration or ``START,DURATION`` values stay supported.
+- H.265 unmux commands no longer force an invalid ``-f h265`` output format, keeping FFmpeg copy extraction aligned with the required Annex B bitstream filter.
+- H.264 encoding now falls back from ``libx264`` to ``libopenh264`` with a warning when needed, and the test fixtures use the same encoder fallback so the suite remains portable across FFmpeg builds.
+
+0.3.0
+-----
+
+- Inspect and edit screens now refresh nested track and pattern changes more reliably, with inspect-mode tables aligned to the target pattern view shown in the differences pane.
+- Metadata editing got a follow-up polish pass with clearer FFmpeg notifications, a shared in-screen log pane, safer apply/reload handling, and expanded cleanup and normalization coverage.
+- Track and asset probing recognize additional codecs, and the modern test suite now covers more metadata-editor, change-set, screen-state, and asset-probe behavior.
+- Textual now requires version ``8.0`` or newer to match the UI APIs used by the current screens.
+
+0.2.6
+-----
+
+- DB-free ``ffx edit`` workflow for in-place metadata editing via temporary-file rewrite.
+- Inspect and edit workflows split into dedicated Textual screens with shared media-workflow support.
+- Textual tables and row actions now separate raw data from rendered labels to avoid markup leaking into stored metadata.
+- Responsive screen layout pass, ``Esc`` back handling, sortable show/inspect tables, and improved edit-screen notifications/toggles.
+- Application-wide UTF-8 i18n catalogs with language precedence from CLI over config over system over German default.
+- Metadata normalization extended for localized subtitle titles, ISO language cleanup, and smarter track editor language/title helpers.
+
+0.2.5
+-----
+
+- Show-level quality and notes fields.
+- Pattern-over-show-over-default season-shift resolution with dynamic DB migration loading.
+- Migration prompt now reports the upgrade path and creates an in-place DB backup before applying schema changes.
+- ``upgrade --branch <name>`` now fetches remote-only branches before switching.
+- ``unmux`` now applies season shifting to subtitle output filenames.
+- Convert now keeps DB-defined target subtitle dispositions authoritative over sidecar filename disposition flags when a pattern definition exists.
+- Focused modern tests added around migrations, unmux, upgrade, and subtitle-disposition import precedence.
+
+0.2.4
+-----
+
+- Lightweight CLI commands now stay import-light via lazy runtime loading.
+- Setup/config templating moved to ``assets/ffx.json.j2``.
+- Aligned two-step local setup wrappers: ``ffx setup`` and ``ffx configure_workstation``.
+- Combined ``ffprobe`` payload reuse in ``FileProperties``.
+- Configurable crop-detect sampling plus per-process crop result caching.
+- Single-query controller accessors and conditional DB schema bootstrap.
+- Shared screen bootstrap/controller wiring for large detail screens.
+- Configurable default season/episode digit lengths.
+- Digit-aware ``rename`` and padded ``unmux`` filename markers.
+
+0.2.3
+-----
+
+- PyPI packaging.
+- Output filename templating.
+- Season shifting.
+- DB versioning.
+
+0.2.2
+-----
+
+- CLI overrides.
+
+0.2.1
+-----
+
+- Signature handling.
+- Tag cleanup.
+- Bugfixes and refactoring.
+
+0.2.0
+-----
+
+- Tests.
+- Config file.
+
+0.1.3
+-----
+
+- Subtitle file imports.
+
+0.1.2
+-----
+
+- Bugfixes.
+
+0.1.1
+-----
+
+- Bugfixes.
+- TMDB show identification.

docs/index.rst

@@ -0,0 +1,31 @@
+FFX Documentation
+=================
+
+FFX is a local command-line and Textual terminal UI for inspecting TV episode
+files, storing normalization rules, and converting media into predictable
+archive-ready outputs.
+
+This documentation covers operator setup, day-to-day command usage, contributor
+workflow, format-specific notes, and generated API references for the smaller
+utility modules.
+
+.. toctree::
+   :maxdepth: 2
+   :caption: User Guide
+
+   installation
+   usage
+   file_formats
+
+.. toctree::
+   :maxdepth: 1
+   :caption: Release Notes
+
+   history
+
+.. toctree::
+   :maxdepth: 2
+   :caption: Contributor Guide
+
+   development
+   api

docs/installation.rst

@@ -0,0 +1,52 @@
+Installation
+============
+
+FFX is designed for a Linux-like workstation with local command execution. The
+runtime media tools must be available on ``PATH``:
+
+* ``ffmpeg``
+* ``ffprobe``
+* ``cpulimit``
+
+User Bundle
+-----------
+
+The persistent user installation is prepared with the two-step flow described in
+the project README:
+
+.. code-block:: sh
+
+   bash tools/setup.sh
+   bash tools/configure_workstation.sh
+
+``tools/setup.sh`` creates the long-lived bundle virtualenv at
+``~/.local/share/ffx.venv`` and exposes the ``ffx`` command. The workstation
+script checks system tools and seeds local config directories.
+
+Local Test And Docs Environment
+-------------------------------
+
+Contributor test and documentation work uses the repo-local virtualenv:
+
+.. code-block:: sh
+
+   tests/prepare.sh
+
+The script creates ``.venv``, installs FFX in editable mode with test and docs
+extras, and verifies the Sphinx toolchain. Use check-only mode when you only
+want to inspect readiness:
+
+.. code-block:: sh
+
+   tests/prepare.sh --check
+
+Documentation Build
+-------------------
+
+After preparation, build the documentation with:
+
+.. code-block:: sh
+
+   .venv/bin/sphinx-build -b html docs docs/_build/html
+
+The generated site starts at ``docs/_build/html/index.html``.

docs/make.bat

@@ -0,0 +1,42 @@
+@ECHO OFF
+
+pushd %~dp0
+
+if "%SPHINXBUILD%" == "" if exist ..\.venv\Scripts\sphinx-build.exe (
+	set SPHINXBUILD=..\.venv\Scripts\sphinx-build.exe
+)
+if "%SPHINXBUILD%" == "" set SPHINXBUILD=sphinx-build
+set SOURCEDIR=.
+set BUILDDIR=_build
+
+%SPHINXBUILD% >NUL 2>NUL
+if errorlevel 9009 (
+	echo.
+	echo The 'sphinx-build' command was not found. Make sure Sphinx is installed,
+	echo then set SPHINXBUILD to the full path if needed.
+	exit /b 1
+)
+
+if "%1" == "" goto help
+if "%1" == "html" goto html
+if "%1" == "linkcheck" goto linkcheck
+echo.
+echo Unknown target "%1".
+goto help
+
+:html
+%SPHINXBUILD% -b html %SOURCEDIR% %BUILDDIR%\html %SPHINXOPTS%
+goto end
+
+:linkcheck
+%SPHINXBUILD% -b linkcheck %SOURCEDIR% %BUILDDIR%\linkcheck %SPHINXOPTS%
+goto end
+
+:help
+echo.
+echo Please use 'make.bat ^<target^>' where ^<target^> is one of
+echo   html       to make standalone HTML files
+echo   linkcheck  to check all external links for integrity
+
+:end
+popd

docs/usage.rst

@@ -0,0 +1,97 @@
+Usage
+=====
+
+FFX exposes a single ``ffx`` command with subcommands for inspection,
+conversion, metadata editing, setup, and maintenance.
+
+Inspect Files
+-------------
+
+Open the inspection workflow for one or more files:
+
+.. code-block:: sh
+
+   ffx inspect /path/to/episode.mkv
+
+Print resolved season-shift mappings without opening the TUI:
+
+.. code-block:: sh
+
+   ffx inspect --shift /path/to/episode.mkv
+
+Convert Files
+-------------
+
+Convert one or more source files using stored rules where available:
+
+.. code-block:: sh
+
+   ffx convert /path/to/episode.mkv
+
+Useful overrides include:
+
+* ``--no-pattern`` to skip database pattern matching
+* ``--show``, ``--season``, and ``--episode`` for explicit episode identity
+* ``--output-directory`` for generated output placement
+* ``--subtitle-directory`` for source-basename sidecar subtitle imports
+* ``--subtitle-prefix`` for explicit or configured-prefix subtitle imports
+* ``--subtitle-extension`` to select the imported sidecar format (default:
+  ``vtt``)
+* ``--yes`` to accept a valid partial sidecar set without prompting
+* ``--copy-video`` or ``--copy-audio`` to preserve selected stream types
+* ``--rename-only`` for filename normalization without media rewriting
+
+Directory-only subtitle import matches the source basename. For example,
+``A2_t01.mkv`` discovers files such as ``A2_t01_2_deu_DEF.vtt`` in the
+provided directory:
+
+.. code-block:: sh
+
+   ffx convert --subtitle-directory /path/to/subtitles A2_t01.mkv
+
+Select a different sidecar set by extension, with or without the leading dot:
+
+.. code-block:: sh
+
+   ffx convert --subtitle-directory /path/to/subtitles \
+     --subtitle-extension .mkv A2_t01.mkv
+
+When only some source subtitle tracks have matching sidecar files, conversion
+asks for confirmation. Use ``--yes`` to substitute that valid subset without
+prompting. ``--yes`` also permits this case when ``--no-prompt`` is set.
+
+Manage Shows And Patterns
+-------------------------
+
+Open the Textual interface for show and pattern management:
+
+.. code-block:: sh
+
+   ffx shows
+
+Extract Streams
+---------------
+
+Extract streams from a file:
+
+.. code-block:: sh
+
+   ffx unmux /path/to/episode.mkv
+
+For subtitle-only extraction:
+
+.. code-block:: sh
+
+   ffx unmux --subtitles-only --label show-name /path/to/episode.mkv
+
+Detect Crop
+-----------
+
+Ask FFmpeg to suggest crop parameters:
+
+.. code-block:: sh
+
+   ffx cropdetect /path/to/episode.mkv
+
+The default sampling window is controlled by the application defaults and can be
+overridden with command options.

pyproject.toml

@@ -1,7 +1,7 @@
 [project]
 name = "ffx"
 description = "FFX recoding and metadata managing tool"
-version = "0.4.2"
+version = "0.4.4"
 license = {file = "LICENSE.md"}
 dependencies = [
   "requests",
@@ -31,6 +31,12 @@ Issues = "https://gitea.maveno.de/Javanaut/ffx/issues"
 test = [
   "pytest",
 ]
+docs = [
+  "esbonio",
+  "sphinx",
+  "sphinx-copybutton",
+  "sphinx-rtd-theme",
+]
 
 [build-system]
 requires = [

src/ffx/cli.py

@@ -41,13 +41,17 @@ CPU_OPTION_HELP = (
     + "Omit to disable; 0 also disables."
 )
 SUBTITLE_DIRECTORY_OPTION_HELP = (
-    "Load subtitles from here. When omitted and --subtitle-prefix is set, "
+    "Load subtitles from here. Without --subtitle-prefix, match the source filename "
+    + "basename. When omitted and --subtitle-prefix is set, "
     + "FFX uses the configured subtitlesDirectory base path plus the prefix as a subdirectory."
 )
 SUBTITLE_PREFIX_OPTION_HELP = (
     "Subtitle filename prefix. Requires --subtitle-directory, or a configured "
     + "subtitlesDirectory base path that contains a matching <prefix>/ subdirectory."
 )
+SUBTITLE_EXTENSION_OPTION_HELP = (
+    "External subtitle filename extension. A leading dot is optional."
+)
 UNMUX_OUTPUT_DIRECTORY_OPTION_HELP = (
     "Write extracted streams here. When omitted together with --subtitles-only and "
     + "--label, FFX uses the configured subtitlesDirectory base path plus the label."
@@ -96,6 +100,18 @@ def normalizeCpuOption(ctx, param, value):
         raise click.BadParameter(str(ex)) from ex
 
 
+def normalizeSubtitleExtension(ctx, param, value):
+    normalizedExtension = str(value).strip().lower()
+    if normalizedExtension.startswith('.'):
+        normalizedExtension = normalizedExtension[1:]
+    if not normalizedExtension or not normalizedExtension.isalnum():
+        raise click.BadParameter(
+            "Subtitle extension must contain only letters and numbers, "
+            + "with an optional leading dot."
+        )
+    return normalizedExtension
+
+
 def parseCutOptionValue(value) -> tuple[int, int] | None:
     if value is None:
         return None
@@ -146,11 +162,21 @@ def resolveSubtitleImportOptions(context, subtitleDirectory, subtitlePrefix):
         else ''
     )
 
-    if not resolvedSubtitlePrefix:
-        return False, resolvedSubtitleDirectory, resolvedSubtitlePrefix
-
     if resolvedSubtitleDirectory:
-        return True, resolvedSubtitleDirectory, resolvedSubtitlePrefix
+        if not os.path.isdir(resolvedSubtitleDirectory):
+            raise click.ClickException(
+                "The provided subtitle directory does not exist: "
+                + resolvedSubtitleDirectory
+            )
+        return (
+            True,
+            resolvedSubtitleDirectory,
+            resolvedSubtitlePrefix,
+            not resolvedSubtitlePrefix,
+        )
+
+    if not resolvedSubtitlePrefix:
+        return False, resolvedSubtitleDirectory, resolvedSubtitlePrefix, False
 
     configuredSubtitlesBaseDirectory = context['config'].getSubtitlesDirectoryPath()
     if not configuredSubtitlesBaseDirectory:
@@ -170,7 +196,85 @@ def resolveSubtitleImportOptions(context, subtitleDirectory, subtitlePrefix):
             + resolvedSubtitleDirectory
         )
 
-    return True, resolvedSubtitleDirectory, resolvedSubtitlePrefix
+    return True, resolvedSubtitleDirectory, resolvedSubtitlePrefix, False
+
+
+def importExternalSubtitles(
+    context,
+    mediaDescriptor,
+    sourceFileBasename,
+    season,
+    episode,
+    preserveDispositions=False,
+):
+    matchSourceBasename = context['subtitle_match_source_basename']
+    subtitlePrefix = (
+        sourceFileBasename
+        if matchSourceBasename
+        else context['subtitle_prefix']
+    )
+
+    try:
+        importResult = mediaDescriptor.importSubtitles(
+            context['subtitle_directory'],
+            subtitlePrefix,
+            season,
+            episode,
+            preserve_dispositions=preserveDispositions,
+            extension=context['subtitle_extension'],
+            strict=matchSourceBasename,
+        )
+    except (OSError, ValueError) as ex:
+        raise click.ClickException(
+            f"External subtitle discovery failed for '{sourceFileBasename}': {ex}"
+        ) from ex
+
+    if not matchSourceBasename:
+        return importResult
+
+    importedTrackIndices = importResult['imported_track_indices']
+    missingTrackIndices = importResult['missing_track_indices']
+    extension = context['subtitle_extension']
+    importedDescription = (
+        ', '.join(f"#{index}" for index in importedTrackIndices)
+        if importedTrackIndices
+        else 'none'
+    )
+    click.echo(
+        f"External subtitle scan for '{sourceFileBasename}': found "
+        + f"{importResult['candidate_count']} .{extension} file(s); "
+        + f"matched subtitle tracks {importedDescription}."
+    )
+
+    if not missingTrackIndices:
+        return importResult
+
+    missingDescription = ', '.join(f"#{index}" for index in missingTrackIndices)
+    incompleteMessage = (
+        f"External subtitle files are missing for subtitle tracks "
+        + f"{missingDescription} in '{sourceFileBasename}'."
+    )
+    if context.get('yes', False):
+        click.echo(
+            incompleteMessage
+            + " Continuing with the matching subtitle files because --yes is set."
+        )
+        return importResult
+
+    if context['no_prompt']:
+        raise click.ClickException(
+            incompleteMessage
+            + " Partial subtitle substitution requires confirmation, but --no-prompt is set."
+        )
+
+    click.echo(incompleteMessage)
+    if not click.confirm(
+        "Continue and substitute only the subtitle tracks with matching files?",
+        default=False,
+    ):
+        raise click.ClickException("External subtitle substitution aborted by user.")
+
+    return importResult
 
 
 def resolveUnmuxOutputDirectory(context, outputDirectory, subtitlesOnly, label):
@@ -181,7 +285,10 @@ def resolveUnmuxOutputDirectory(context, outputDirectory, subtitlesOnly, label):
     )
     resolvedLabel = str(label).strip()
 
-    if resolvedOutputDirectory or not subtitlesOnly or not resolvedLabel:
+    if resolvedOutputDirectory:
+        return resolvedOutputDirectory, True
+
+    if not subtitlesOnly or not resolvedLabel:
         return resolvedOutputDirectory, False
 
     configuredSubtitlesBaseDirectory = context['config'].getSubtitlesDirectoryPath()
@@ -194,6 +301,63 @@ def resolveUnmuxOutputDirectory(context, outputDirectory, subtitlesOnly, label):
     return os.path.join(configuredSubtitlesBaseDirectory, resolvedLabel), True
 
 
+def confirmUnmuxOutputDirectoryCreation(outputDirectory):
+    message = (
+        "Create unmux output directory and missing parents: "
+        + str(outputDirectory)
+    )
+
+    if not sys.stdin.isatty():
+        return click.confirm(message, default=True)
+
+    click.echo(f"{message} [Y/n]: ", nl=False)
+    while True:
+        char = click.getchar()
+        if char in ('\r', '\n'):
+            click.echo()
+            return True
+
+        normalizedChar = char.lower()
+        if normalizedChar == 'y':
+            click.echo(char)
+            return True
+        if normalizedChar == 'n':
+            click.echo(char)
+            return False
+        if char in ('\x03', '\x04'):
+            raise click.Abort()
+
+        click.echo("\nPlease respond with 'y' or 'n': ", nl=False)
+
+
+def ensureUnmuxOutputDirectory(context, outputDirectory):
+    resolvedOutputDirectory = os.path.expanduser(str(outputDirectory).strip())
+    if not resolvedOutputDirectory:
+        return False
+
+    if os.path.isdir(resolvedOutputDirectory):
+        return False
+
+    if os.path.exists(resolvedOutputDirectory):
+        raise click.ClickException(
+            "Unmux output path exists but is not a directory: "
+            + resolvedOutputDirectory
+        )
+
+    if context.get('dry_run', False):
+        return False
+
+    if context.get('yes', False):
+        os.makedirs(resolvedOutputDirectory, exist_ok=True)
+        return True
+
+    if not confirmUnmuxOutputDirectoryCreation(resolvedOutputDirectory):
+        raise click.ClickException("Unmux output directory creation aborted by user.")
+
+    os.makedirs(resolvedOutputDirectory, exist_ok=True)
+    return True
+
+
 def resolveIndicatorDigitLengths(context=None, showDescriptor=None):
     from ffx.show_descriptor import ShowDescriptor
 
@@ -716,6 +880,12 @@ def getUnmuxSequence(trackDescriptor: TrackDescriptor, sourcePath, targetPrefix,
 @click.option('-l', '--label', type=str, default='', help='Label to be used as filename prefix')
 @click.option("-o", "--output-directory", type=str, default='', help=UNMUX_OUTPUT_DIRECTORY_OPTION_HELP)
 @click.option("-s", "--subtitles-only", is_flag=True, default=False)
+@click.option(
+    "--yes",
+    is_flag=True,
+    default=False,
+    help="Create a missing unmux output directory without prompting.",
+)
 @click.option(
     '--nice',
     type=int,
@@ -737,6 +907,7 @@ def unmux(ctx,
             label,
             output_directory,
             subtitles_only,
+            yes,
             nice,
             cpu):
     from ffx.file_properties import FileProperties
@@ -752,15 +923,16 @@ def unmux(ctx,
     ctx.obj['resource_limits']['niceness'] = nice
     ctx.obj['resource_limits']['cpu_limit'] = cpu
     ctx.obj['resource_limits']['cpu_percent'] = cpu
+    ctx.obj['yes'] = bool(yes)
 
-    output_directory, create_output_directory = resolveUnmuxOutputDirectory(
+    output_directory, requires_output_directory = resolveUnmuxOutputDirectory(
         ctx.obj,
         output_directory,
         subtitles_only,
         label,
     )
-    if create_output_directory and existingSourcePaths and not ctx.obj.get('dry_run', False):
-        os.makedirs(output_directory, exist_ok=True)
+    if requires_output_directory and existingSourcePaths:
+        ensureUnmuxOutputDirectory(ctx.obj, output_directory)
 
     shiftedSeasonController = ShiftedSeasonController(ctx.obj)
 
@@ -974,6 +1146,14 @@ def checkUniqueDispositions(context, mediaDescriptor: MediaDescriptor):
 
 @click.option('--subtitle-directory', type=str, default='', help=SUBTITLE_DIRECTORY_OPTION_HELP)
 @click.option('--subtitle-prefix', type=str, default='', help=SUBTITLE_PREFIX_OPTION_HELP)
+@click.option(
+    '--subtitle-extension',
+    type=str,
+    default='vtt',
+    callback=normalizeSubtitleExtension,
+    show_default=True,
+    help=SUBTITLE_EXTENSION_OPTION_HELP,
+)
 
 @click.option('--language', type=str, multiple=True, help='Set stream language. Use format <stream index>:<3 letter iso code>')
 @click.option('--title', type=str, multiple=True, help='Set stream title. Use format <stream index>:<title>')
@@ -1034,6 +1214,12 @@ def checkUniqueDispositions(context, mediaDescriptor: MediaDescriptor):
 @click.option("--dont-pass-dispositions", is_flag=True, default=False)
 
 @click.option("--no-prompt", is_flag=True, default=False)
+@click.option(
+    "--yes",
+    is_flag=True,
+    default=False,
+    help="Confirm partial external subtitle substitution without prompting.",
+)
 @click.option("--no-signature", is_flag=True, default=False)
 @click.option("--keep-mkvmerge-metadata", is_flag=True, default=False)
 
@@ -1070,6 +1256,7 @@ def convert(ctx,
 
             subtitle_directory,
             subtitle_prefix,
+            subtitle_extension,
 
             language,
             title,
@@ -1108,6 +1295,7 @@ def convert(ctx,
             no_pattern,
             dont_pass_dispositions,
             no_prompt,
+            yes,
             no_signature,
             keep_mkvmerge_metadata,
             
@@ -1139,6 +1327,7 @@ def convert(ctx,
     from ffx.tmdb_controller import TmdbController
     from ffx.track_codec import TrackCodec
     from ffx.track_disposition import TrackDisposition
+    from ffx.track_type import TrackType
     from ffx.video_encoder import VideoEncoder
 
     startTime = time.perf_counter()
@@ -1161,6 +1350,7 @@ def convert(ctx,
     context['use_tmdb'] = not no_tmdb
     context['use_pattern'] = not no_pattern
     context['no_prompt'] = no_prompt
+    context['yes'] = yes
     context['no_signature'] = no_signature
     context['keep_mkvmerge_metadata'] = keep_mkvmerge_metadata
 
@@ -1179,6 +1369,7 @@ def convert(ctx,
         context['import_subtitles'],
         resolvedSubtitleDirectory,
         resolvedSubtitlePrefix,
+        context['subtitle_match_source_basename'],
     ) = resolveSubtitleImportOptions(
         context,
         subtitle_directory,
@@ -1187,6 +1378,7 @@ def convert(ctx,
     if context['import_subtitles']:
         context['subtitle_directory'] = resolvedSubtitleDirectory
         context['subtitle_prefix'] = resolvedSubtitlePrefix
+        context['subtitle_extension'] = subtitle_extension
 
 
     existingSourcePaths = [p for p in paths if os.path.isfile(p) and p.split('.')[-1] in SUPPORTED_INPUT_FILE_EXTENSIONS]
@@ -1393,13 +1585,29 @@ def convert(ctx,
 
         from ffx.attachment_format import AttachmentFormat
 
-        if ([smd for smd in sourceMediaDescriptor.getSubtitleTracks()
-                    if smd.getCodec() == TrackCodec.ASS]
-                and [amd for amd in sourceMediaDescriptor.getAttachmentTracks()
-                    if amd.getAttachmentFormat() == AttachmentFormat.TTF]):
-            
+        styledAssDetector = getattr(
+            sourceMediaDescriptor,
+            "hasStyledAssSubtitlesWithFontAttachments",
+            None,
+        )
+        styledAssSourceDetected = (
+            bool(styledAssDetector())
+            if callable(styledAssDetector)
+            else False
+        )
+        if styledAssSourceDetected:
+            styledAssMessage = (
+                "Styled ASS subtitles with embedded font attachments detected; "
+                + "preserving source font attachments."
+            )
+            click.echo(styledAssMessage)
             targetFormat = ''
             targetExtension = 'mkv'
+            if context['import_subtitles']:
+                raise click.ClickException(
+                    "External subtitle import is incompatible with styled ASS "
+                    + "sources that carry embedded font attachments."
+                )
 
 
         #HINT: This is None if the filename did not match anything in database
@@ -1414,10 +1622,13 @@ def convert(ctx,
             currentShowDescriptor = None
 
             if context['import_subtitles']:
-                sourceMediaDescriptor.importSubtitles(context['subtitle_directory'],
-                                                        context['subtitle_prefix'],
-                                                        showSeason,
-                                                        showEpisode)
+                importExternalSubtitles(
+                    context,
+                    sourceMediaDescriptor,
+                    sourceFileBasename,
+                    showSeason,
+                    showEpisode,
+                )
 
             if cliOverrides:
                 sourceMediaDescriptor.applyOverrides(cliOverrides)
@@ -1426,6 +1637,12 @@ def convert(ctx,
 
         else:
             targetMediaDescriptor = currentPattern.getMediaDescriptor(ctx.obj)
+            if styledAssSourceDetected:
+                targetMediaDescriptor = targetMediaDescriptor.withSourceAttachmentTracks(
+                    sourceMediaDescriptor,
+                    AttachmentFormat.TTF,
+                    context=ctx.obj,
+                )
             checkUniqueDispositions(context, targetMediaDescriptor)
             currentShowDescriptor = currentPattern.getShowDescriptor(ctx.obj)
 
@@ -1435,6 +1652,8 @@ def convert(ctx,
             targetTrackDescriptorList = targetMediaDescriptor.getTrackDescriptors()
 
             for ttd in targetTrackDescriptorList:
+                if ttd.getType() == TrackType.ATTACHMENT:
+                    continue
 
                 tti = ttd.getIndex()
                 ttsi = ttd.getSourceIndex()
@@ -1453,11 +1672,14 @@ def convert(ctx,
 
 
             if context['import_subtitles']:
-                targetMediaDescriptor.importSubtitles(context['subtitle_directory'],
-                                                        context['subtitle_prefix'],
-                                                        showSeason,
-                                                        showEpisode,
-                                                        preserve_dispositions=True)
+                importExternalSubtitles(
+                    context,
+                    targetMediaDescriptor,
+                    sourceFileBasename,
+                    showSeason,
+                    showEpisode,
+                    preserveDispositions=True,
+                )
 
             # ctx.obj['logger'].debug(f"tmd subindices: {[t.getIndex() for t in targetMediaDescriptor.getAllTrackDescriptors()]} {[t.getSubIndex() for t in targetMediaDescriptor.getAllTrackDescriptors()]}  {[t.getDispositionFlag(TrackDisposition.DEFAULT) for t in targetMediaDescriptor.getAllTrackDescriptors()]}")
             ctx.obj['logger'].debug(f"tmd subindices: {[t.getIndex() for t in targetMediaDescriptor.getTrackDescriptors()]} {[t.getSubIndex() for t in targetMediaDescriptor.getTrackDescriptors()]}  {[t.getDispositionFlag(TrackDisposition.DEFAULT) for t in targetMediaDescriptor.getTrackDescriptors()]}")

src/ffx/constants.py

@@ -1,4 +1,4 @@
-VERSION='0.4.2'
+VERSION='0.4.4'
 DATABASE_VERSION = 3
 
 DEFAULT_QUALITY = 32

src/ffx/media_descriptor.py

@@ -329,6 +329,96 @@ class MediaDescriptor:
             if s.getType() == TrackType.ATTACHMENT
         ]
 
+    def hasStyledAssSubtitlesWithFontAttachments(self) -> bool:
+        return (
+            any(
+                trackDescriptor.getCodec() == TrackCodec.ASS
+                for trackDescriptor in self.getSubtitleTracks()
+            )
+            and any(
+                trackDescriptor.getAttachmentFormat() == AttachmentFormat.TTF
+                for trackDescriptor in self.getAttachmentTracks()
+            )
+        )
+
+    def withoutAttachmentTracks(
+        self,
+        attachmentFormat: AttachmentFormat | None = None,
+        context: dict | None = None,
+    ):
+        filteredTrackDescriptors = []
+        for trackDescriptor in self.__trackDescriptors:
+            if trackDescriptor.getType() == TrackType.ATTACHMENT and (
+                attachmentFormat is None
+                or trackDescriptor.getAttachmentFormat() == attachmentFormat
+            ):
+                continue
+            filteredTrackDescriptors.append(
+                trackDescriptor.clone(
+                    context=context if context is not None else self.__context
+                )
+            )
+
+        kwargs = {
+            MediaDescriptor.TAGS_KEY: dict(self.__mediaTags),
+            MediaDescriptor.TRACK_DESCRIPTOR_LIST_KEY: filteredTrackDescriptors,
+        }
+        if context is not None:
+            kwargs[MediaDescriptor.CONTEXT_KEY] = context
+        elif self.__context:
+            kwargs[MediaDescriptor.CONTEXT_KEY] = self.__context
+
+        filteredMediaDescriptor = MediaDescriptor(**kwargs)
+        filteredMediaDescriptor.reindexSubIndices()
+        return filteredMediaDescriptor
+
+    def withoutAttachmentsForComparison(self):
+        return self.withoutAttachmentTracks(context=self.__context)
+
+    def withSourceAttachmentTracks(
+        self,
+        sourceMediaDescriptor: Self,
+        attachmentFormat: AttachmentFormat | None = None,
+        context: dict | None = None,
+    ):
+        trackDescriptors = []
+        for trackDescriptor in self.__trackDescriptors:
+            if trackDescriptor.getType() == TrackType.ATTACHMENT and (
+                attachmentFormat is None
+                or trackDescriptor.getAttachmentFormat() == attachmentFormat
+            ):
+                continue
+            trackDescriptors.append(
+                trackDescriptor.clone(
+                    context=context if context is not None else self.__context
+                )
+            )
+
+        for sourceTrackDescriptor in sourceMediaDescriptor.getAttachmentTracks():
+            if (
+                attachmentFormat is not None
+                and sourceTrackDescriptor.getAttachmentFormat() != attachmentFormat
+            ):
+                continue
+            attachmentClone = sourceTrackDescriptor.clone(
+                context=context if context is not None else self.__context
+            )
+            attachmentClone.setIndex(len(trackDescriptors))
+            trackDescriptors.append(attachmentClone)
+
+        kwargs = {
+            MediaDescriptor.TAGS_KEY: dict(self.__mediaTags),
+            MediaDescriptor.TRACK_DESCRIPTOR_LIST_KEY: trackDescriptors,
+        }
+        if context is not None:
+            kwargs[MediaDescriptor.CONTEXT_KEY] = context
+        elif self.__context:
+            kwargs[MediaDescriptor.CONTEXT_KEY] = self.__context
+
+        mergedMediaDescriptor = MediaDescriptor(**kwargs)
+        mergedMediaDescriptor.reindexSubIndices()
+        return mergedMediaDescriptor
+
 
     def getImportFileTokens(self, use_sub_index: bool = True):
         """Generate ffmpeg import options for external stream files"""
@@ -341,10 +431,13 @@ class MediaDescriptor:
             importedFilePath = td.getExternalSourceFilePath()
 
             if importedFilePath:
-
-                self.__logger.info(f"Substituting subtitle stream #{td.getIndex()} "
-                                    + f"({td.getType().label()}:{td.getSubIndex()}) "
-                                    + f"with import from file {td.getExternalSourceFilePath()}")
+                substitutionMessage = (
+                    f"Substituting subtitle stream #{td.getIndex()} "
+                    + f"({td.getType().label()}:{td.getSubIndex()}) "
+                    + f"with import from file {td.getExternalSourceFilePath()}"
+                )
+                click.echo(substitutionMessage)
+                self.__logger.debug(substitutionMessage)
 
                 importFileTokens += [
                     "-i",
@@ -434,66 +527,153 @@ class MediaDescriptor:
         return inputMappingTokens
 
 
-    def searchSubtitleFiles(self, searchDirectory, prefix):
+    def searchSubtitleFiles(
+        self,
+        searchDirectory,
+        prefix,
+        extension=SUBTITLE_FILE_EXTENSION,
+        strict=False,
+    ):
 
-        sesld_match = re.compile(f"{prefix}_{MediaDescriptor.SEASON_EPISODE_STREAM_LANGUAGE_DISPOSITIONS_MATCH}")
-        sld_match = re.compile(f"{prefix}_{MediaDescriptor.STREAM_LANGUAGE_DISPOSITIONS_MATCH}")
+        normalizedExtension = str(extension).strip().lower()
+        if normalizedExtension.startswith('.'):
+            normalizedExtension = normalizedExtension[1:]
+        escapedPrefix = re.escape(prefix)
+        sesld_match = re.compile(
+            f"{escapedPrefix}_{MediaDescriptor.SEASON_EPISODE_STREAM_LANGUAGE_DISPOSITIONS_MATCH}"
+        )
+        sld_match = re.compile(
+            f"{escapedPrefix}_{MediaDescriptor.STREAM_LANGUAGE_DISPOSITIONS_MATCH}"
+        )
 
         subtitleFileDescriptors = []
+        subtitleFilenames = []
 
-        for subtitleFilename in os.listdir(searchDirectory):
-            if subtitleFilename.startswith(prefix) and subtitleFilename.endswith(
-                "." + MediaDescriptor.SUBTITLE_FILE_EXTENSION
+        for subtitleFilename in sorted(os.listdir(searchDirectory)):
+            subtitleFilePath = os.path.join(searchDirectory, subtitleFilename)
+            subtitleFilenameStem, subtitleFilenameExtension = os.path.splitext(
+                subtitleFilename
+            )
+            if (
+                os.path.isfile(subtitleFilePath)
+                and subtitleFilenameStem.startswith(prefix + '_')
+                and subtitleFilenameExtension.lower() == '.' + normalizedExtension
             ):
+                subtitleFilenames.append(subtitleFilename)
 
-                sesld_result = sesld_match.search(subtitleFilename)
-                sld_result = None if not sesld_result is None else sld_match.search(subtitleFilename)
+        expectedSubtitleTrackIndices = {
+            subtitleTrack.getIndex()
+            for subtitleTrack in self.getSubtitleTracks()
+        }
+        if strict and len(subtitleFilenames) > len(expectedSubtitleTrackIndices):
+            raise ValueError(
+                f"Found {len(subtitleFilenames)} matching .{normalizedExtension} files "
+                + f"for {len(expectedSubtitleTrackIndices)} subtitle tracks."
+            )
 
-                if not sesld_result is None:
+        for subtitleFilename in subtitleFilenames:
+            subtitleFilenameStem = os.path.splitext(subtitleFilename)[0]
+            sesld_result = (
+                None
+                if strict
+                else sesld_match.fullmatch(subtitleFilenameStem)
+            )
+            sld_result = (
+                None
+                if sesld_result is not None
+                else sld_match.fullmatch(subtitleFilenameStem)
+            )
 
-                    subtitleFilePath = os.path.join(searchDirectory, subtitleFilename)
-                    if os.path.isfile(subtitleFilePath):
+            if strict and sesld_result is None and sld_result is None:
+                raise ValueError(
+                    f"Subtitle filename does not match the expected pattern: "
+                    + subtitleFilename
+                )
 
-                        subtitleFileDescriptor = {}
-                        subtitleFileDescriptor["path"] = subtitleFilePath
-                        subtitleFileDescriptor["season"] = int(sesld_result.group(1))
-                        subtitleFileDescriptor["episode"] = int(sesld_result.group(2))
-                        subtitleFileDescriptor["index"] = int(sesld_result.group(3))
-                        subtitleFileDescriptor["language"] = sesld_result.group(4)
+            if sesld_result is not None:
 
-                        dispSet = set()
-                        dispCaptGroups = sesld_result.groups()
-                        numCaptGroups = len(dispCaptGroups)
-                        if numCaptGroups > 4:
-                            for groupIndex in range(numCaptGroups - 4):
-                                disp = TrackDisposition.fromIndicator(dispCaptGroups[groupIndex + 4])
-                                if disp is not None:
-                                    dispSet.add(disp)
-                        subtitleFileDescriptor["disposition_set"] = dispSet
+                subtitleFilePath = os.path.join(searchDirectory, subtitleFilename)
 
-                        subtitleFileDescriptors.append(subtitleFileDescriptor)
+                subtitleFileDescriptor = {}
+                subtitleFileDescriptor["path"] = subtitleFilePath
+                subtitleFileDescriptor["season"] = int(sesld_result.group(1))
+                subtitleFileDescriptor["episode"] = int(sesld_result.group(2))
+                subtitleFileDescriptor["index"] = int(sesld_result.group(3))
+                subtitleFileDescriptor["language"] = sesld_result.group(4)
 
-                if not sld_result is None:
+                dispSet = set()
+                dispCaptGroups = sesld_result.groups()
+                numCaptGroups = len(dispCaptGroups)
+                if numCaptGroups > 4:
+                    for groupIndex in range(numCaptGroups - 4):
+                        disp = TrackDisposition.fromIndicator(
+                            dispCaptGroups[groupIndex + 4]
+                        )
+                        if disp is not None:
+                            dispSet.add(disp)
+                subtitleFileDescriptor["disposition_set"] = dispSet
 
-                    subtitleFilePath = os.path.join(searchDirectory, subtitleFilename)
-                    if os.path.isfile(subtitleFilePath):
+                subtitleFileDescriptors.append(subtitleFileDescriptor)
 
-                        subtitleFileDescriptor = {}
-                        subtitleFileDescriptor["path"] = subtitleFilePath
-                        subtitleFileDescriptor["index"] = int(sld_result.group(1))
-                        subtitleFileDescriptor["language"] = sld_result.group(2)
+            if sld_result is not None:
 
-                        dispSet = set()
-                        dispCaptGroups = sld_result.groups()
-                        numCaptGroups = len(dispCaptGroups)
-                        if numCaptGroups > 2:
-                            for groupIndex in range(numCaptGroups - 2):
-                                disp = TrackDisposition.fromIndicator(dispCaptGroups[groupIndex + 2])
-                                if disp is not None:
-                                    dispSet.add(disp)
-                        subtitleFileDescriptor["disposition_set"] = dispSet
+                subtitleFilePath = os.path.join(searchDirectory, subtitleFilename)
 
-                        subtitleFileDescriptors.append(subtitleFileDescriptor)
+                subtitleFileDescriptor = {}
+                subtitleFileDescriptor["path"] = subtitleFilePath
+                subtitleFileDescriptor["index"] = int(sld_result.group(1))
+                subtitleFileDescriptor["language"] = sld_result.group(2)
+
+                dispSet = set()
+                dispCaptGroups = sld_result.groups()
+                numCaptGroups = len(dispCaptGroups)
+                if numCaptGroups > 2:
+                    for groupIndex in range(numCaptGroups - 2):
+                        disp = TrackDisposition.fromIndicator(
+                            dispCaptGroups[groupIndex + 2]
+                        )
+                        if disp is not None:
+                            dispSet.add(disp)
+                subtitleFileDescriptor["disposition_set"] = dispSet
+
+                subtitleFileDescriptors.append(subtitleFileDescriptor)
+
+        if strict:
+            discoveredTrackIndices = [
+                descriptor['index'] for descriptor in subtitleFileDescriptors
+            ]
+            duplicateTrackIndices = sorted(
+                {
+                    trackIndex
+                    for trackIndex in discoveredTrackIndices
+                    if discoveredTrackIndices.count(trackIndex) > 1
+                }
+            )
+            if duplicateTrackIndices:
+                duplicateDescription = ', '.join(
+                    f"#{index}" for index in duplicateTrackIndices
+                )
+                raise ValueError(
+                    "Multiple external subtitle files refer to subtitle track(s) "
+                    + duplicateDescription
+                    + "."
+                )
+
+            unexpectedTrackIndices = sorted(
+                set(discoveredTrackIndices) - expectedSubtitleTrackIndices
+            )
+            if unexpectedTrackIndices:
+                unexpectedDescription = ', '.join(
+                    f"#{index}" for index in unexpectedTrackIndices
+                )
+                expectedDescription = ', '.join(
+                    f"#{index}" for index in sorted(expectedSubtitleTrackIndices)
+                ) or 'none'
+                raise ValueError(
+                    "External subtitle track index pattern does not match the media "
+                    + f"subtitle tracks: found {unexpectedDescription}; "
+                    + f"expected a subset of {expectedDescription}."
+                )
 
 
         self.__logger.debug(f"searchSubtitleFiles(): Available subtitle files {subtitleFileDescriptors}")
@@ -508,12 +688,19 @@ class MediaDescriptor:
         season: int = -1,
         episode: int = -1,
         preserve_dispositions: bool = False,
+        extension: str = SUBTITLE_FILE_EXTENSION,
+        strict: bool = False,
     ):
         
         # click.echo(f"Season: {season} Episode: {episode}")
         self.__logger.debug(f"importSubtitles(): Season: {season} Episode: {episode}")
 
-        availableFileSubtitleDescriptors = self.searchSubtitleFiles(searchDirectory, prefix)
+        availableFileSubtitleDescriptors = self.searchSubtitleFiles(
+            searchDirectory,
+            prefix,
+            extension=extension,
+            strict=strict,
+        )
         
         self.__logger.debug(f"importSubtitles(): availableFileSubtitleDescriptors: {availableFileSubtitleDescriptors}")
 
@@ -526,7 +713,8 @@ class MediaDescriptor:
                 [
                     d
                     for d in availableFileSubtitleDescriptors
-                    if ((season == -1 and episode == -1)
+                    if (strict
+                        or (season == -1 and episode == -1)
                         or (
                             d.get("season") == int(season)
                             and d.get("episode") == int(episode)
@@ -540,6 +728,7 @@ class MediaDescriptor:
 
         self.__logger.debug(f"importSubtitles(): matchingSubtitleFileDescriptors: {matchingSubtitleFileDescriptors}")
 
+        importedTrackIndices = []
         for msfd in matchingSubtitleFileDescriptors:
             matchingSubtitleTrackDescriptor = [s for s in subtitleTracks if s.getIndex() == msfd["index"]]
             if matchingSubtitleTrackDescriptor:
@@ -553,6 +742,19 @@ class MediaDescriptor:
                 matchingTrack.getTags()["language"] = msfd["language"]
                 if msfd["disposition_set"] and not preserve_dispositions:
                     matchingTrack.setDispositionSet(msfd["disposition_set"])
+                importedTrackIndices.append(matchingTrack.getIndex())
+
+        expectedTrackIndices = sorted(
+            subtitleTrack.getIndex() for subtitleTrack in subtitleTracks
+        )
+        importedTrackIndices = sorted(set(importedTrackIndices))
+        return {
+            "candidate_count": len(availableFileSubtitleDescriptors),
+            "imported_track_indices": importedTrackIndices,
+            "missing_track_indices": sorted(
+                set(expectedTrackIndices) - set(importedTrackIndices)
+            ),
+        }
 
 
     def getConfiguration(self, label: str = ''):

src/ffx/media_descriptor_change_set.py

@@ -56,8 +56,24 @@ class MediaDescriptorChangeSet():
                                     and 'ignore' in metadataConfiguration['streams'].keys() else [])
 
 
-        self.__targetTrackDescriptors = targetMediaDescriptor.getTrackDescriptors() if targetMediaDescriptor is not None else []
-        self.__sourceTrackDescriptors = sourceMediaDescriptor.getTrackDescriptors() if sourceMediaDescriptor is not None else []
+        self.__targetTrackDescriptors = (
+            [
+                trackDescriptor
+                for trackDescriptor in targetMediaDescriptor.getTrackDescriptors()
+                if trackDescriptor.getType() != TrackType.ATTACHMENT
+            ]
+            if targetMediaDescriptor is not None
+            else []
+        )
+        self.__sourceTrackDescriptors = (
+            [
+                trackDescriptor
+                for trackDescriptor in sourceMediaDescriptor.getTrackDescriptors()
+                if trackDescriptor.getType() != TrackType.ATTACHMENT
+            ]
+            if sourceMediaDescriptor is not None
+            else []
+        )
         self.__targetTrackDescriptorsByIndex = {
             trackDescriptor.getIndex(): trackDescriptor
             for trackDescriptor in self.__targetTrackDescriptors

src/ffx/media_workflow_screen_base.py

@@ -166,10 +166,9 @@ class MediaWorkflowScreenBase(Screen):
             self._baselineMediaDescriptor = probedMediaDescriptor
             self._sourceMediaDescriptor = probedMediaDescriptor
             self._currentPattern = self._mediaFileProperties.getPattern()
-            self._targetMediaDescriptor = (
-                self._currentPattern.getMediaDescriptor(self.context)
-                if self._currentPattern is not None
-                else None
+            self._targetMediaDescriptor = self._resolve_target_media_descriptor(
+                self._currentPattern,
+                self._sourceMediaDescriptor,
             )
 
         self.rebuildChangeSet()
@@ -205,6 +204,25 @@ class MediaWorkflowScreenBase(Screen):
     def getTrackEditSourceDescriptor(self) -> TrackDescriptor | None:
         return self.getSelectedTrackDescriptor()
 
+    def _resolve_target_media_descriptor(self, currentPattern, sourceMediaDescriptor):
+        if currentPattern is None:
+            return None
+
+        targetMediaDescriptor = currentPattern.getMediaDescriptor(self.context)
+        styledAssDetector = getattr(
+            sourceMediaDescriptor,
+            "hasStyledAssSubtitlesWithFontAttachments",
+            None,
+        )
+        if callable(styledAssDetector) and styledAssDetector():
+            targetMediaDescriptor = targetMediaDescriptor.withSourceAttachmentTracks(
+                sourceMediaDescriptor,
+                AttachmentFormat.TTF,
+                context=self.context,
+            )
+
+        return targetMediaDescriptor
+
     def updateMediaTags(self):
         displayedMediaDescriptor = self.getDisplayedMediaDescriptor()
         self._sourceMediaTagRowData = populate_tag_table(

src/ffx/model/pattern.py

@@ -7,6 +7,7 @@ from .show import Base, Show
 
 from ffx.media_descriptor import MediaDescriptor
 from ffx.show_descriptor import ShowDescriptor
+from ffx.track_type import TrackType
 
 
 class Pattern(Base):
@@ -76,6 +77,8 @@ class Pattern(Base):
         subIndexCounter = {}
         for track in self.tracks:
             trackType = track.getType()
+            if trackType == TrackType.ATTACHMENT:
+                continue
             if not trackType in subIndexCounter.keys():
                 subIndexCounter[trackType] = 0
             kwargs[MediaDescriptor.TRACK_DESCRIPTOR_LIST_KEY].append(track.getDescriptor(context, subIndex = subIndexCounter[trackType]))

src/ffx/pattern_controller.py

@@ -8,6 +8,7 @@ from ffx.model.track import Track
 from ffx.model.track_tag import TrackTag
 from ffx.track_descriptor import TrackDescriptor
 from ffx.track_disposition import TrackDisposition
+from ffx.track_type import TrackType
 
 
 class DuplicatePatternMatchError(click.ClickException):
@@ -86,12 +87,16 @@ class PatternController:
             )
 
         normalized_descriptors = []
+        filtered_attachments = False
         for trackDescriptor in trackDescriptors:
             if type(trackDescriptor) is not TrackDescriptor:
                 raise TypeError(
                     "PatternController: All track descriptors are required to be of type TrackDescriptor"
                 )
-            normalized_descriptors.append(trackDescriptor)
+            if trackDescriptor.getType() == TrackType.ATTACHMENT:
+                filtered_attachments = True
+                continue
+            normalized_descriptors.append(trackDescriptor.clone())
 
         if not normalized_descriptors:
             raise InvalidPatternSchemaError(
@@ -102,6 +107,10 @@ class PatternController:
             normalized_descriptors, key=lambda descriptor: descriptor.getIndex()
         )
 
+        if filtered_attachments:
+            for index, descriptor in enumerate(normalized_descriptors):
+                descriptor.setIndex(index)
+
         index_set = {descriptor.getIndex() for descriptor in normalized_descriptors}
         expected_indexes = set(range(len(normalized_descriptors)))
         if index_set != expected_indexes:
@@ -170,7 +179,7 @@ class PatternController:
             pattern.tracks.append(self._build_track_row(trackDescriptor))
 
     def _validate_persisted_pattern(self, pattern: Pattern):
-        if not pattern.tracks:
+        if not any(track.getType() != TrackType.ATTACHMENT for track in pattern.tracks):
             raise InvalidPatternSchemaError(
                 f"Pattern #{pattern.getId()} ({pattern.getPattern()!r}) is invalid because it has no tracks."
             )

src/ffx/track_controller.py

@@ -35,6 +35,8 @@ class TrackController():
 
 
     def addTrack(self, trackDescriptor : TrackDescriptor, patternId = None):
+        if trackDescriptor.getType() == TrackType.ATTACHMENT:
+            return False
 
         # option to override pattern id in case track descriptor has not set it
         patId = int(trackDescriptor.getPatternId() if patternId is None else patternId)
@@ -72,6 +74,8 @@ class TrackController():
 
         if type(trackDescriptor) is not TrackDescriptor:
             raise TypeError('TrackController.updateTrack(): Argument trackDescriptor is required to be of type TrackDescriptor')
+        if trackDescriptor.getType() == TrackType.ATTACHMENT:
+            return False
 
         try:
             s = self.Session()

tests/integration/subtrack_mapping/test_cli_bundle.py

@@ -18,6 +18,7 @@ from tests.support.ffx_bundle import (
     write_vtt,
 )
 
+from ffx.attachment_format import AttachmentFormat
 from ffx.track_type import TrackType
 
 try:
@@ -280,6 +281,72 @@ class SubtrackMappingBundleTests(unittest.TestCase):
         self.assertIn("non-existent source track #99", error_output)
         self.assertFalse(expected_output_path(self.workdir, source_filename).exists())
 
+    def test_styled_ass_source_preserves_current_font_attachments_when_pattern_count_differs(self):
+        source_filename = "styled_ass_s01e01.mkv"
+        source_path = create_source_fixture(
+            self.workdir,
+            source_filename,
+            [
+                SourceTrackSpec(TrackType.VIDEO, identity="video-0"),
+                SourceTrackSpec(TrackType.AUDIO, identity="audio-1", language="eng"),
+                SourceTrackSpec(
+                    TrackType.SUBTITLE,
+                    identity="subtitle-2",
+                    language="eng",
+                    subtitle_lines=("styled subtitle payload",),
+                ),
+                SourceTrackSpec(TrackType.ATTACHMENT, attachment_name="current.ttf"),
+            ],
+            subtitle_encoder="ass",
+        )
+
+        prepare_pattern_database(
+            self.database_path,
+            r"^styled_ass_(s[0-9]+e[0-9]+)\.mkv$",
+            [
+                PatternTrackSpec(index=0, source_index=0, track_type=TrackType.VIDEO),
+                PatternTrackSpec(index=1, source_index=1, track_type=TrackType.AUDIO),
+                PatternTrackSpec(index=2, source_index=2, track_type=TrackType.SUBTITLE),
+                PatternTrackSpec(
+                    index=3,
+                    source_index=3,
+                    track_type=TrackType.ATTACHMENT,
+                    attachment_format=AttachmentFormat.TTF,
+                ),
+                PatternTrackSpec(
+                    index=4,
+                    source_index=4,
+                    track_type=TrackType.ATTACHMENT,
+                    attachment_format=AttachmentFormat.TTF,
+                ),
+            ],
+        )
+
+        completed = run_ffx_convert(
+            self.workdir,
+            self.home_dir,
+            self.database_path,
+            "--video-encoder",
+            "copy",
+            "--no-tmdb",
+            "--no-prompt",
+            "--no-signature",
+            str(source_path),
+        )
+        self.assertCompleted(completed)
+        self.assertIn("Styled ASS subtitles", completed.stdout)
+
+        output_path = expected_output_path(self.workdir, source_filename)
+        streams = ffprobe_json(output_path)["streams"]
+
+        self.assertEqual(
+            [stream["codec_type"] for stream in streams],
+            ["video", "audio", "subtitle", "attachment"],
+        )
+        self.assertEqual(streams[2]["codec_name"], "ass")
+        self.assertEqual(streams[3]["codec_name"], "ttf")
+        self.assertEqual(get_tag(streams[3], "filename"), "current.ttf")
+
     def test_external_subtitle_file_replaces_payload_and_overrides_metadata(self):
         source_filename = "substitute_s01e01.mkv"
         self.write_config(
@@ -354,6 +421,59 @@ class SubtrackMappingBundleTests(unittest.TestCase):
         self.assertIn("external subtitle payload", extracted_subtitle)
         self.assertNotIn("embedded subtitle payload", extracted_subtitle)
 
+    def test_subtitle_directory_without_prefix_uses_source_basename(self):
+        source_filename = "basename_substitute.mkv"
+        subtitle_directory = self.workdir / "sidecars"
+        subtitle_directory.mkdir()
+        source_path = create_source_fixture(
+            self.workdir,
+            source_filename,
+            [
+                SourceTrackSpec(TrackType.VIDEO, identity="video-0"),
+                SourceTrackSpec(TrackType.AUDIO, identity="audio-1", language="eng"),
+                SourceTrackSpec(
+                    TrackType.SUBTITLE,
+                    identity="embedded-subtitle",
+                    language="eng",
+                    subtitle_lines=("embedded subtitle payload",),
+                ),
+            ],
+        )
+        write_vtt(
+            subtitle_directory / "basename_substitute_2_deu_DEF.vtt",
+            ("external subtitle payload",),
+        )
+
+        completed = run_ffx_convert(
+            self.workdir,
+            self.home_dir,
+            self.database_path,
+            "--video-encoder",
+            "copy",
+            "--no-pattern",
+            "--no-tmdb",
+            "--no-prompt",
+            "--no-signature",
+            "--subtitle-directory",
+            str(subtitle_directory),
+            str(source_path),
+        )
+        self.assertCompleted(completed)
+        self.assertIn("matched subtitle tracks #2", completed.stdout)
+        self.assertIn("Substituting subtitle stream #2", completed.stdout)
+
+        output_path = expected_output_path(self.workdir, source_filename)
+        subtitle_stream = [
+            stream
+            for stream in ffprobe_json(output_path)["streams"]
+            if stream["codec_type"] == "subtitle"
+        ][0]
+        self.assertEqual("deu", get_tag(subtitle_stream, "language"))
+
+        extracted_subtitle = extract_first_subtitle_text(self.workdir, output_path)
+        self.assertIn("external subtitle payload", extracted_subtitle)
+        self.assertNotIn("embedded subtitle payload", extracted_subtitle)
+
     def test_subtitle_prefix_uses_configured_base_directory_when_directory_is_omitted(self):
         source_filename = "substitute_default_s01e01.mkv"
         subtitle_prefix = "substitute_default"

tests/integration/test_cli_unmux.py

@@ -35,7 +35,13 @@ if pytest is not None:
 SRC_ROOT = Path(__file__).resolve().parents[2] / "src"
 
 
-def run_ffx_unmux(workdir: Path, home_dir: Path, database_path: Path, *args: str) -> subprocess.CompletedProcess[str]:
+def run_ffx_unmux(
+    workdir: Path,
+    home_dir: Path,
+    database_path: Path,
+    *args: str,
+    input_text: str | None = None,
+) -> subprocess.CompletedProcess[str]:
     env = os.environ.copy()
     env["HOME"] = str(home_dir)
     existing_pythonpath = env.get("PYTHONPATH", "")
@@ -50,7 +56,14 @@ def run_ffx_unmux(workdir: Path, home_dir: Path, database_path: Path, *args: str
         "unmux",
         *args,
     ]
-    return subprocess.run(command, cwd=workdir, env=env, capture_output=True, text=True)
+    return subprocess.run(
+        command,
+        cwd=workdir,
+        env=env,
+        capture_output=True,
+        input=input_text,
+        text=True,
+    )
 
 
 class UnmuxCliTests(unittest.TestCase):
@@ -161,6 +174,7 @@ class UnmuxCliTests(unittest.TestCase):
             self.home_dir,
             self.database_path,
             "--subtitles-only",
+            "--yes",
             "--label",
             "dball",
             str(source_path),

tests/prepare.sh

@@ -0,0 +1,471 @@
+#!/usr/bin/env bash
+
+set -u
+
+SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
+ROOT_DIR="$(cd -- "${SCRIPT_DIR}/.." && pwd)"
+VENV_DIR="${FFX_TEST_VENV_DIR:-${ROOT_DIR}/.venv}"
+VENV_BIN_DIR="${VENV_DIR}/bin"
+VENV_PYTHON="${VENV_BIN_DIR}/python"
+VENV_PIP="${VENV_BIN_DIR}/pip"
+
+CHECK_ONLY=0
+READINESS_FAILURES=0
+INSTALL_FAILURES=0
+
+MISSING_REQUIRED_SYSTEM=()
+
+COLOR_RESET=""
+COLOR_GREEN=""
+COLOR_YELLOW=""
+COLOR_RED=""
+
+if [ -t 1 ]; then
+    COLOR_RESET="$(printf '\033[0m')"
+    COLOR_GREEN="$(printf '\033[32m')"
+    COLOR_YELLOW="$(printf '\033[33m')"
+    COLOR_RED="$(printf '\033[31m')"
+fi
+
+usage() {
+    cat <<EOF
+Usage: $(basename "$0") [--check] [--help]
+
+Prepare the repo-local FFX test environment at:
+  ${VENV_DIR}
+
+Actions:
+  - verify or install required system commands for tests
+  - create or reuse the repo-local test virtualenv
+  - install this repository into the venv with Python test and docs extras
+
+Options:
+  --check  Report readiness only. Do not create, install, or modify.
+  --help   Show this help text.
+
+Environment overrides:
+  FFX_TEST_VENV_DIR  Override the test virtualenv path. Defaults to ${ROOT_DIR}/.venv.
+
+Notes:
+  - This script prepares a project-local test environment, not the persistent user bundle.
+  - The persistent bundle setup remains owned by tools/setup.sh.
+EOF
+}
+
+status_ok() {
+    printf '%sok%s' "${COLOR_GREEN}" "${COLOR_RESET}"
+}
+
+status_warn() {
+    printf '%swarn%s' "${COLOR_YELLOW}" "${COLOR_RESET}"
+}
+
+status_fail() {
+    printf '%sfailed%s' "${COLOR_RED}" "${COLOR_RESET}"
+}
+
+report_component() {
+    local level="$1"
+    local label="$2"
+    local detail="$3"
+    local rendered_status=""
+
+    case "${level}" in
+        ok)
+            rendered_status="$(status_ok)"
+            ;;
+        warn)
+            rendered_status="$(status_warn)"
+            ;;
+        *)
+            rendered_status="$(status_fail)"
+            ;;
+    esac
+
+    printf '[%s] %s%s\n' "${rendered_status}" "${label}" "${detail:+: $detail}"
+}
+
+command_exists() {
+    command -v "$1" >/dev/null 2>&1
+}
+
+check_python_venv_support() {
+    python3 -m venv --help >/dev/null 2>&1
+}
+
+check_system_command() {
+    command_exists "$1"
+}
+
+check_venv_python() {
+    [ -x "${VENV_PYTHON}" ]
+}
+
+check_venv_pip() {
+    check_venv_python && "${VENV_PIP}" --version >/dev/null 2>&1
+}
+
+check_venv_ffx() {
+    check_venv_python && "${VENV_PYTHON}" -m ffx version >/dev/null 2>&1
+}
+
+check_venv_pytest() {
+    check_venv_python && "${VENV_PYTHON}" -m pytest --version >/dev/null 2>&1
+}
+
+check_venv_sphinx() {
+    check_venv_python && "${VENV_BIN_DIR}/sphinx-build" --version >/dev/null 2>&1
+}
+
+check_venv_docs_packages() {
+    check_venv_python && "${VENV_PYTHON}" - <<'PY' >/dev/null 2>&1
+import esbonio
+import sphinx
+import sphinx_rtd_theme
+PY
+}
+
+check_editable_install() {
+    check_venv_python && FFX_REPO_ROOT="${ROOT_DIR}" "${VENV_PYTHON}" - <<'PY' >/dev/null 2>&1
+from __future__ import annotations
+
+import os
+from pathlib import Path
+import ffx
+
+repo_root = Path(os.environ["FFX_REPO_ROOT"]).resolve()
+package_path = Path(ffx.__file__).resolve()
+
+raise SystemExit(0 if repo_root in package_path.parents else 1)
+PY
+}
+
+check_python_environment_ready() {
+    check_venv_python &&
+        check_venv_pip &&
+        check_venv_pytest &&
+        check_venv_sphinx &&
+        check_venv_docs_packages &&
+        check_venv_ffx &&
+        check_editable_install
+}
+
+command_detail() {
+    command -v "$1" || printf "command '%s' not found" "$1"
+}
+
+python_venv_detail() {
+    if check_python_venv_support; then
+        printf 'python3 -m venv is available'
+    else
+        printf 'python3 venv support is unavailable'
+    fi
+}
+
+venv_python_detail() {
+    if check_venv_python; then
+        printf '%s' "${VENV_PYTHON}"
+    else
+        printf 'missing %s' "${VENV_PYTHON}"
+    fi
+}
+
+venv_pip_detail() {
+    if check_venv_pip; then
+        "${VENV_PIP}" --version
+    else
+        printf 'missing pip in %s' "${VENV_DIR}"
+    fi
+}
+
+venv_ffx_detail() {
+    if check_venv_ffx; then
+        printf 'ffx import and CLI entry are available'
+    else
+        printf 'ffx is not installed in %s' "${VENV_DIR}"
+    fi
+}
+
+venv_pytest_detail() {
+    if check_venv_pytest; then
+        "${VENV_PYTHON}" -m pytest --version 2>/dev/null | head -n 1
+    else
+        printf 'pytest is not installed in %s' "${VENV_DIR}"
+    fi
+}
+
+venv_sphinx_detail() {
+    if check_venv_sphinx; then
+        "${VENV_BIN_DIR}/sphinx-build" --version 2>&1
+    else
+        printf 'sphinx-build is not installed in %s' "${VENV_DIR}"
+    fi
+}
+
+venv_docs_packages_detail() {
+    if check_venv_docs_packages; then
+        printf 'Sphinx, Read the Docs theme, and Esbonio packages are importable'
+    else
+        printf 'one or more docs packages are missing in %s' "${VENV_DIR}"
+    fi
+}
+
+editable_install_detail() {
+    if check_editable_install; then
+        printf 'ffx resolves from %s' "${ROOT_DIR}"
+    else
+        printf 'ffx does not resolve from the project source tree'
+    fi
+}
+
+report_required_command() {
+    local label="$1"
+    local command_name="$2"
+
+    if check_system_command "${command_name}"; then
+        report_component ok "${label}" "$(command_detail "${command_name}")"
+    else
+        report_component failed "${label}" "$(command_detail "${command_name}")"
+        MISSING_REQUIRED_SYSTEM+=("${command_name}")
+        READINESS_FAILURES=$((READINESS_FAILURES + 1))
+    fi
+}
+
+print_system_status() {
+    MISSING_REQUIRED_SYSTEM=()
+
+    echo "System toolchain status:"
+    report_required_command "git" "git"
+    report_required_command "python3" "python3"
+
+    if check_system_command "python3" && check_python_venv_support; then
+        report_component ok "python3 venv" "$(python_venv_detail)"
+    else
+        report_component failed "python3 venv" "$(python_venv_detail)"
+        MISSING_REQUIRED_SYSTEM+=("python3-venv")
+        READINESS_FAILURES=$((READINESS_FAILURES + 1))
+    fi
+
+    report_required_command "ffmpeg" "ffmpeg"
+    report_required_command "ffprobe" "ffprobe"
+    report_required_command "cpulimit" "cpulimit"
+}
+
+print_python_status() {
+    echo "Repo test and docs virtualenv status:"
+
+    if check_venv_python; then
+        report_component ok "test virtualenv" "$(venv_python_detail)"
+    else
+        report_component failed "test virtualenv" "$(venv_python_detail)"
+        READINESS_FAILURES=$((READINESS_FAILURES + 1))
+    fi
+
+    if check_venv_pip; then
+        report_component ok "test pip" "$(venv_pip_detail)"
+    else
+        report_component failed "test pip" "$(venv_pip_detail)"
+        READINESS_FAILURES=$((READINESS_FAILURES + 1))
+    fi
+
+    if check_venv_pytest; then
+        report_component ok "test pytest" "$(venv_pytest_detail)"
+    else
+        report_component failed "test pytest" "$(venv_pytest_detail)"
+        READINESS_FAILURES=$((READINESS_FAILURES + 1))
+    fi
+
+    if check_venv_sphinx; then
+        report_component ok "docs sphinx" "$(venv_sphinx_detail)"
+    else
+        report_component failed "docs sphinx" "$(venv_sphinx_detail)"
+        READINESS_FAILURES=$((READINESS_FAILURES + 1))
+    fi
+
+    if check_venv_docs_packages; then
+        report_component ok "docs packages" "$(venv_docs_packages_detail)"
+    else
+        report_component failed "docs packages" "$(venv_docs_packages_detail)"
+        READINESS_FAILURES=$((READINESS_FAILURES + 1))
+    fi
+
+    if check_venv_ffx; then
+        report_component ok "test ffx" "$(venv_ffx_detail)"
+    else
+        report_component failed "test ffx" "$(venv_ffx_detail)"
+        READINESS_FAILURES=$((READINESS_FAILURES + 1))
+    fi
+
+    if check_editable_install; then
+        report_component ok "editable source" "$(editable_install_detail)"
+    else
+        report_component failed "editable source" "$(editable_install_detail)"
+        READINESS_FAILURES=$((READINESS_FAILURES + 1))
+    fi
+}
+
+print_status_report() {
+    READINESS_FAILURES=0
+
+    print_system_status
+    echo
+    print_python_status
+}
+
+detect_package_manager() {
+    if command_exists apt-get; then
+        printf 'apt-get\n'
+        return 0
+    fi
+    if command_exists pacman; then
+        printf 'pacman\n'
+        return 0
+    fi
+    return 1
+}
+
+run_root_command() {
+    if [ "${EUID}" -eq 0 ]; then
+        "$@"
+    elif command_exists sudo; then
+        sudo -n "$@"
+    else
+        return 1
+    fi
+}
+
+install_system_requirements() {
+    local package_manager
+
+    if [ "${#MISSING_REQUIRED_SYSTEM[@]}" -eq 0 ]; then
+        return 0
+    fi
+
+    if ! package_manager="$(detect_package_manager)"; then
+        printf 'No supported package manager found for automatic system preparation.\n' >&2
+        INSTALL_FAILURES=$((INSTALL_FAILURES + 1))
+        return 1
+    fi
+
+    case "${package_manager}" in
+        apt-get)
+            printf 'Installing required system dependencies via apt-get...\n'
+            if ! run_root_command apt-get update; then
+                printf 'apt-get update failed or requires interactive sudo.\n' >&2
+                INSTALL_FAILURES=$((INSTALL_FAILURES + 1))
+                return 1
+            fi
+            if ! run_root_command apt-get install -y git python3 python3-venv ffmpeg cpulimit; then
+                printf 'apt-get install failed or requires interactive sudo.\n' >&2
+                INSTALL_FAILURES=$((INSTALL_FAILURES + 1))
+                return 1
+            fi
+            ;;
+        pacman)
+            printf 'Installing required system dependencies via pacman...\n'
+            if ! run_root_command pacman -Sy --noconfirm git python ffmpeg cpulimit; then
+                printf 'pacman install failed or requires interactive sudo.\n' >&2
+                INSTALL_FAILURES=$((INSTALL_FAILURES + 1))
+                return 1
+            fi
+            ;;
+    esac
+
+    return 0
+}
+
+ensure_test_venv() {
+    if ! check_venv_python; then
+        printf 'Creating repo test virtualenv at %s...\n' "${VENV_DIR}"
+        if ! python3 -m venv "${VENV_DIR}"; then
+            printf 'Failed to create test virtualenv at %s.\n' "${VENV_DIR}" >&2
+            INSTALL_FAILURES=$((INSTALL_FAILURES + 1))
+            return 1
+        fi
+    fi
+
+    if ! check_venv_pip; then
+        printf 'Missing pip in %s.\n' "${VENV_DIR}" >&2
+        INSTALL_FAILURES=$((INSTALL_FAILURES + 1))
+        return 1
+    fi
+
+    printf 'Installing FFX package with test and docs extras into %s...\n' "${VENV_DIR}"
+    if ! (
+        cd "${ROOT_DIR}" &&
+        "${VENV_PIP}" install --editable '.[test,docs]'
+    ); then
+        printf 'Failed to install FFX package with test and docs extras into %s.\n' "${VENV_DIR}" >&2
+        INSTALL_FAILURES=$((INSTALL_FAILURES + 1))
+        return 1
+    fi
+
+    return 0
+}
+
+parse_args() {
+    while [ "$#" -gt 0 ]; do
+        case "$1" in
+            --check)
+                CHECK_ONLY=1
+                ;;
+            --help|-h)
+                usage
+                exit 0
+                ;;
+            *)
+                printf 'Unknown option: %s\n\n' "$1" >&2
+                usage >&2
+                exit 2
+                ;;
+        esac
+        shift
+    done
+}
+
+main() {
+    parse_args "$@"
+
+    print_status_report
+
+    if [ "${CHECK_ONLY}" -eq 0 ]; then
+        if [ "${#MISSING_REQUIRED_SYSTEM[@]}" -gt 0 ]; then
+            echo
+            install_system_requirements
+        fi
+
+        if check_python_environment_ready; then
+            echo
+            report_component ok "Python package install" "repo test and docs virtualenv is already ready"
+        elif check_system_command "python3" && check_python_venv_support; then
+            echo
+            ensure_test_venv
+        fi
+
+        echo
+        print_status_report
+    fi
+
+    echo
+    if [ "${INSTALL_FAILURES}" -gt 0 ]; then
+        echo "One or more test preparation steps failed; see the status checks above." >&2
+        exit 1
+    fi
+
+    if [ "${READINESS_FAILURES}" -gt 0 ]; then
+        if [ "${CHECK_ONLY}" -eq 1 ]; then
+            echo "The FFX test and docs environment is incomplete." >&2
+        else
+            echo "Required test or docs components are still missing after preparation." >&2
+        fi
+        exit 1
+    fi
+
+    if [ "${CHECK_ONLY}" -eq 1 ]; then
+        echo "The FFX test and docs environment is ready."
+    else
+        echo "The FFX test and docs environment is prepared."
+    fi
+}
+
+main "$@"

tests/support/ffx_bundle.py

@@ -18,6 +18,7 @@ if str(SRC_ROOT) not in sys.path:
     sys.path.insert(0, str(SRC_ROOT))
 
 
+from ffx.attachment_format import AttachmentFormat
 from ffx.audio_layout import AudioLayout
 from ffx.database import databaseContext
 from ffx.pattern_controller import PatternController
@@ -56,6 +57,7 @@ class PatternTrackSpec:
     tags: Mapping[str, str] = field(default_factory=dict)
     dispositions: tuple[TrackDisposition, ...] = ()
     audio_layout: AudioLayout = AudioLayout.LAYOUT_STEREO
+    attachment_format: AttachmentFormat = AttachmentFormat.UNKNOWN
 
 
 def make_logger(name: str) -> logging.Logger:
@@ -299,6 +301,8 @@ def prepare_pattern_database(database_path: Path, filename_pattern: str, track_s
             }
             if track.track_type == TrackType.AUDIO:
                 kwargs[TrackDescriptor.AUDIO_LAYOUT_KEY] = track.audio_layout
+            if track.track_type == TrackType.ATTACHMENT:
+                kwargs[TrackDescriptor.ATTACHMENT_FORMAT_KEY] = track.attachment_format
             track_descriptors.append(TrackDescriptor(**kwargs))
 
         pattern_id = PatternController(context).savePatternSchema(

tests/unit/test_cli_subtitle_directory.py

@@ -6,7 +6,9 @@ from pathlib import Path
 import sys
 import tempfile
 import unittest
+from unittest.mock import patch
 
+import click
 from click.testing import CliRunner
 
 
@@ -17,6 +19,10 @@ if str(SRC_ROOT) not in sys.path:
 
 
 from ffx import cli  # noqa: E402
+from ffx.logging_utils import get_ffx_logger  # noqa: E402
+from ffx.media_descriptor import MediaDescriptor  # noqa: E402
+from ffx.track_descriptor import TrackDescriptor  # noqa: E402
+from ffx.track_type import TrackType  # noqa: E402
 
 
 class SubtitleDirectoryCliTests(unittest.TestCase):
@@ -48,6 +54,35 @@ class SubtitleDirectoryCliTests(unittest.TestCase):
             env={**os.environ, "HOME": str(self.home_dir)},
         )
 
+    def make_subtitle_descriptor(self, indices=(2, 3, 4)) -> MediaDescriptor:
+        return MediaDescriptor(
+            context={"logger": get_ffx_logger()},
+            track_descriptors=[
+                TrackDescriptor(
+                    index=index,
+                    source_index=index,
+                    sub_index=subIndex,
+                    track_type=TrackType.SUBTITLE,
+                )
+                for subIndex, index in enumerate(indices)
+            ],
+        )
+
+    def make_import_context(
+        self,
+        subtitleDirectory: Path,
+        noPrompt: bool,
+        yes: bool = False,
+    ) -> dict:
+        return {
+            "subtitle_match_source_basename": True,
+            "subtitle_directory": str(subtitleDirectory),
+            "subtitle_prefix": "",
+            "subtitle_extension": "vtt",
+            "no_prompt": noPrompt,
+            "yes": yes,
+        }
+
     def test_subtitle_prefix_without_directory_or_default_fails(self):
         result = self.invoke_convert("--subtitle-prefix", "dball")
 
@@ -79,6 +114,153 @@ class SubtitleDirectoryCliTests(unittest.TestCase):
 
         self.assertEqual(0, result.exit_code, result.output)
 
+    def test_explicit_directory_without_prefix_enables_basename_matching(self):
+        explicitSubtitleDirectory = self.home_dir / "manual-subtitles"
+        explicitSubtitleDirectory.mkdir(parents=True, exist_ok=True)
+
+        enabled, directory, prefix, matchBasename = cli.resolveSubtitleImportOptions(
+            {},
+            str(explicitSubtitleDirectory),
+            "",
+        )
+
+        self.assertTrue(enabled)
+        self.assertEqual(str(explicitSubtitleDirectory), directory)
+        self.assertEqual("", prefix)
+        self.assertTrue(matchBasename)
+
+    def test_subtitle_extension_accepts_optional_leading_dot(self):
+        self.assertEqual("mkv", cli.normalizeSubtitleExtension(None, None, "mkv"))
+        self.assertEqual("mkv", cli.normalizeSubtitleExtension(None, None, ".mkv"))
+
+    def test_subtitle_extension_rejects_multiple_leading_dots(self):
+        with self.assertRaises(click.BadParameter):
+            cli.normalizeSubtitleExtension(None, None, "..mkv")
+
+    def test_complete_basename_set_does_not_prompt(self):
+        subtitleDirectory = self.home_dir / "complete-subtitles"
+        subtitleDirectory.mkdir()
+        for basename in (
+            "A2_t01_2_deu_DEF",
+            "A2_t01_3_eng",
+            "A2_t01_4_eng",
+        ):
+            (subtitleDirectory / f"{basename}.vtt").write_text(
+                "WEBVTT\n\n",
+                encoding="utf-8",
+            )
+        descriptor = self.make_subtitle_descriptor()
+        context = self.make_import_context(subtitleDirectory, noPrompt=True)
+
+        with patch("ffx.cli.click.confirm") as mockedConfirm:
+            result = cli.importExternalSubtitles(
+                context,
+                descriptor,
+                "A2_t01",
+                -1,
+                -1,
+            )
+
+        self.assertEqual([], result["missing_track_indices"])
+        mockedConfirm.assert_not_called()
+
+    def test_incomplete_basename_set_fails_with_no_prompt(self):
+        descriptor = self.make_subtitle_descriptor()
+        subtitleDirectory = self.home_dir / "partial-subtitles"
+        subtitleDirectory.mkdir()
+        (subtitleDirectory / "episode_2_deu.vtt").write_text(
+            "WEBVTT\n\n",
+            encoding="utf-8",
+        )
+        context = self.make_import_context(subtitleDirectory, noPrompt=True)
+
+        with patch("ffx.cli.click.confirm") as mockedConfirm:
+            with self.assertRaisesRegex(click.ClickException, "--no-prompt is set"):
+                cli.importExternalSubtitles(
+                    context,
+                    descriptor,
+                    "episode",
+                    -1,
+                    -1,
+                )
+
+        mockedConfirm.assert_not_called()
+
+    def test_incomplete_basename_set_can_be_confirmed(self):
+        descriptor = self.make_subtitle_descriptor()
+        subtitleDirectory = self.home_dir / "partial-subtitles"
+        subtitleDirectory.mkdir()
+        (subtitleDirectory / "episode_2_deu.vtt").write_text(
+            "WEBVTT\n\n",
+            encoding="utf-8",
+        )
+        context = self.make_import_context(subtitleDirectory, noPrompt=False)
+
+        with patch("ffx.cli.click.confirm", return_value=True) as mockedConfirm:
+            result = cli.importExternalSubtitles(
+                context,
+                descriptor,
+                "episode",
+                -1,
+                -1,
+            )
+
+        self.assertEqual([3, 4], result["missing_track_indices"])
+        mockedConfirm.assert_called_once()
+
+    def test_incomplete_basename_set_with_yes_does_not_prompt(self):
+        descriptor = self.make_subtitle_descriptor()
+        subtitleDirectory = self.home_dir / "partial-subtitles"
+        subtitleDirectory.mkdir()
+        (subtitleDirectory / "episode_2_deu.vtt").write_text(
+            "WEBVTT\n\n",
+            encoding="utf-8",
+        )
+        context = self.make_import_context(
+            subtitleDirectory,
+            noPrompt=False,
+            yes=True,
+        )
+
+        with patch("ffx.cli.click.confirm") as mockedConfirm:
+            result = cli.importExternalSubtitles(
+                context,
+                descriptor,
+                "episode",
+                -1,
+                -1,
+            )
+
+        self.assertEqual([2], result["imported_track_indices"])
+        self.assertEqual([3, 4], result["missing_track_indices"])
+        mockedConfirm.assert_not_called()
+
+    def test_yes_takes_precedence_over_no_prompt_for_incomplete_set(self):
+        descriptor = self.make_subtitle_descriptor()
+        subtitleDirectory = self.home_dir / "partial-subtitles"
+        subtitleDirectory.mkdir()
+        (subtitleDirectory / "episode_2_deu.vtt").write_text(
+            "WEBVTT\n\n",
+            encoding="utf-8",
+        )
+        context = self.make_import_context(
+            subtitleDirectory,
+            noPrompt=True,
+            yes=True,
+        )
+
+        with patch("ffx.cli.click.confirm") as mockedConfirm:
+            result = cli.importExternalSubtitles(
+                context,
+                descriptor,
+                "episode",
+                -1,
+                -1,
+            )
+
+        self.assertEqual([3, 4], result["missing_track_indices"])
+        mockedConfirm.assert_not_called()
+
 
 if __name__ == "__main__":
     unittest.main()

tests/unit/test_cli_unmux_output_directory.py

@@ -4,6 +4,7 @@ from pathlib import Path
 import sys
 import tempfile
 import unittest
+from unittest.mock import patch
 
 import click
 
@@ -42,7 +43,7 @@ class UnmuxOutputDirectoryTests(unittest.TestCase):
         self.assertEqual(str(Path(tempdir) / "subtitles" / "dball"), resolved_output_directory)
         self.assertTrue(should_create)
 
-    def test_explicit_output_directory_keeps_existing_behavior(self):
+    def test_explicit_output_directory_requires_directory(self):
         with tempfile.TemporaryDirectory() as tempdir:
             context = {
                 "config": StaticConfig(str(Path(tempdir) / "subtitles")),
@@ -57,7 +58,7 @@ class UnmuxOutputDirectoryTests(unittest.TestCase):
             )
 
         self.assertEqual(explicit_output_directory, resolved_output_directory)
-        self.assertFalse(should_create)
+        self.assertTrue(should_create)
 
     def test_subtitles_only_without_label_keeps_existing_behavior(self):
         context = {
@@ -89,6 +90,110 @@ class UnmuxOutputDirectoryTests(unittest.TestCase):
 
         self.assertIn("subtitlesDirectory default", str(caught.exception))
 
+    def test_missing_output_directory_can_be_confirmed_and_created_with_parents(self):
+        with tempfile.TemporaryDirectory() as tempdir:
+            output_directory = Path(tempdir) / "missing" / "parents" / "manual"
+
+            with patch("ffx.cli.click.confirm", return_value=True) as mocked_confirm:
+                created = cli.ensureUnmuxOutputDirectory(
+                    {"dry_run": False},
+                    str(output_directory),
+                )
+
+            self.assertTrue(created)
+            self.assertTrue(output_directory.is_dir())
+            mocked_confirm.assert_called_once()
+
+    def test_tty_carriage_return_accepts_default_directory_creation(self):
+        with tempfile.TemporaryDirectory() as tempdir:
+            output_directory = Path(tempdir) / "missing" / "manual"
+
+            with patch("ffx.cli.sys.stdin.isatty", return_value=True), patch(
+                "ffx.cli.click.getchar",
+                return_value="\r",
+            ) as mocked_getchar, patch("ffx.cli.click.confirm") as mocked_confirm:
+                created = cli.ensureUnmuxOutputDirectory(
+                    {"dry_run": False},
+                    str(output_directory),
+                )
+
+            self.assertTrue(created)
+            self.assertTrue(output_directory.is_dir())
+            mocked_getchar.assert_called_once()
+            mocked_confirm.assert_not_called()
+
+    def test_yes_creates_missing_output_directory_without_prompt(self):
+        with tempfile.TemporaryDirectory() as tempdir:
+            output_directory = Path(tempdir) / "missing" / "parents" / "manual"
+
+            with patch("ffx.cli.click.confirm") as mocked_confirm:
+                created = cli.ensureUnmuxOutputDirectory(
+                    {"dry_run": False, "yes": True},
+                    str(output_directory),
+                )
+
+            self.assertTrue(created)
+            self.assertTrue(output_directory.is_dir())
+            mocked_confirm.assert_not_called()
+
+    def test_missing_output_directory_can_be_rejected(self):
+        with tempfile.TemporaryDirectory() as tempdir:
+            output_directory = Path(tempdir) / "missing" / "manual"
+
+            with patch("ffx.cli.click.confirm", return_value=False) as mocked_confirm:
+                with self.assertRaises(click.ClickException) as caught:
+                    cli.ensureUnmuxOutputDirectory(
+                        {"dry_run": False},
+                        str(output_directory),
+                    )
+
+            self.assertFalse(output_directory.exists())
+            self.assertIn("aborted by user", str(caught.exception))
+            mocked_confirm.assert_called_once()
+
+    def test_existing_output_directory_does_not_prompt(self):
+        with tempfile.TemporaryDirectory() as tempdir:
+            output_directory = Path(tempdir) / "manual"
+            output_directory.mkdir()
+
+            with patch("ffx.cli.click.confirm") as mocked_confirm:
+                created = cli.ensureUnmuxOutputDirectory(
+                    {"dry_run": False},
+                    str(output_directory),
+                )
+
+            self.assertFalse(created)
+            mocked_confirm.assert_not_called()
+
+    def test_existing_non_directory_output_path_fails_without_prompt(self):
+        with tempfile.TemporaryDirectory() as tempdir:
+            output_path = Path(tempdir) / "manual"
+            output_path.write_text("not a directory", encoding="utf-8")
+
+            with patch("ffx.cli.click.confirm") as mocked_confirm:
+                with self.assertRaises(click.ClickException) as caught:
+                    cli.ensureUnmuxOutputDirectory(
+                        {"dry_run": False},
+                        str(output_path),
+                    )
+
+            self.assertIn("not a directory", str(caught.exception))
+            mocked_confirm.assert_not_called()
+
+    def test_dry_run_does_not_prompt_or_create_missing_output_directory(self):
+        with tempfile.TemporaryDirectory() as tempdir:
+            output_directory = Path(tempdir) / "missing" / "manual"
+
+            with patch("ffx.cli.click.confirm") as mocked_confirm:
+                created = cli.ensureUnmuxOutputDirectory(
+                    {"dry_run": True},
+                    str(output_directory),
+                )
+
+            self.assertFalse(created)
+            self.assertFalse(output_directory.exists())
+            mocked_confirm.assert_not_called()
+
 
 if __name__ == "__main__":
     unittest.main()

tests/unit/test_media_descriptor_change_set.py

@@ -13,6 +13,7 @@ if str(SRC_ROOT) not in sys.path:
 
 from ffx.media_descriptor import MediaDescriptor  # noqa: E402
 from ffx.media_descriptor_change_set import MediaDescriptorChangeSet  # noqa: E402
+from ffx.attachment_format import AttachmentFormat  # noqa: E402
 from ffx.track_descriptor import TrackDescriptor  # noqa: E402
 from ffx.track_type import TrackType  # noqa: E402
 from ffx.i18n import set_current_language  # noqa: E402
@@ -436,6 +437,47 @@ class MediaDescriptorChangeSetTests(unittest.TestCase):
         self.assertNotIn("creation_time=", metadata_tokens)
         self.assertNotIn("BPS=", metadata_tokens)
 
+    def test_attachment_tracks_are_ignored_for_pattern_comparison(self):
+        context = {
+            "logger": get_ffx_logger(),
+            "config": StaticConfig({}),
+        }
+
+        source_track = TrackDescriptor(
+            index=0,
+            source_index=0,
+            sub_index=0,
+            track_type=TrackType.ATTACHMENT,
+            attachment_format=AttachmentFormat.TTF,
+            tags={"filename": "current.ttf", "mimetype": "font/ttf"},
+        )
+        target_track = TrackDescriptor(
+            index=0,
+            source_index=0,
+            sub_index=0,
+            track_type=TrackType.ATTACHMENT,
+            attachment_format=AttachmentFormat.TTF,
+            tags={"filename": "stored.ttf", "mimetype": "font/ttf"},
+        )
+        stale_target_track = TrackDescriptor(
+            index=1,
+            source_index=1,
+            sub_index=1,
+            track_type=TrackType.ATTACHMENT,
+            attachment_format=AttachmentFormat.TTF,
+            tags={"filename": "missing.ttf", "mimetype": "font/ttf"},
+        )
+
+        change_set = MediaDescriptorChangeSet(
+            context,
+            MediaDescriptor(track_descriptors=[target_track, stale_target_track]),
+            MediaDescriptor(track_descriptors=[source_track]),
+        )
+
+        self.assertEqual({}, change_set.getChangeSetObj())
+        self.assertEqual([], change_set.generateMetadataTokens())
+        self.assertEqual([], change_set.generateDispositionTokens())
+
     def test_normalization_can_be_disabled_per_context(self):
         context = {
             "logger": get_ffx_logger(),

tests/unit/test_media_descriptor_import_subtitles.py

@@ -20,18 +20,32 @@ from ffx.track_type import TrackType  # noqa: E402
 
 
 class MediaDescriptorImportSubtitlesTests(unittest.TestCase):
-    def make_descriptor(self) -> MediaDescriptor:
+    COMPLETE_SIDECAR_NAMES = (
+        "A2_t01_2_deu_DEF",
+        "A2_t01_3_eng",
+        "A2_t01_4_eng",
+    )
+
+    def write_complete_sidecar_set(self, directory: str, extension: str) -> None:
+        for basename in self.COMPLETE_SIDECAR_NAMES:
+            (Path(directory) / f"{basename}.{extension}").write_text(
+                "WEBVTT\n\n",
+                encoding="utf-8",
+            )
+
+    def make_descriptor(self, indices=(3,)) -> MediaDescriptor:
         return MediaDescriptor(
             context={"logger": get_ffx_logger()},
             track_descriptors=[
                 TrackDescriptor(
-                    index=3,
-                    source_index=3,
-                    sub_index=0,
+                    index=index,
+                    source_index=index,
+                    sub_index=subIndex,
                     track_type=TrackType.SUBTITLE,
                     tags={"language": "eng", "title": "DB Subtitle"},
                     disposition_set={TrackDisposition.DEFAULT},
                 )
+                for subIndex, index in enumerate(indices)
             ],
         )
 
@@ -74,6 +88,114 @@ class MediaDescriptorImportSubtitlesTests(unittest.TestCase):
         self.assertEqual("deu", track.getTags()["language"])
         self.assertEqual({TrackDisposition.FORCED}, track.getDispositionSet())
 
+    def test_strict_basename_import_recognizes_vtt_asset_set(self):
+        descriptor = self.make_descriptor(indices=(2, 3, 4))
+
+        with tempfile.TemporaryDirectory() as tmpdir:
+            self.write_complete_sidecar_set(tmpdir, "vtt")
+            result = descriptor.importSubtitles(
+                tmpdir,
+                "A2_t01",
+                strict=True,
+            )
+
+        self.assertEqual(3, result["candidate_count"])
+        self.assertEqual([2, 3, 4], result["imported_track_indices"])
+        self.assertEqual([], result["missing_track_indices"])
+        self.assertEqual(
+            [
+                "A2_t01_2_deu_DEF.vtt",
+                "A2_t01_3_eng.vtt",
+                "A2_t01_4_eng.vtt",
+            ],
+            [
+                Path(track.getExternalSourceFilePath()).name
+                for track in descriptor.getSubtitleTracks()
+            ],
+        )
+
+    def test_strict_basename_import_accepts_dotted_mkv_extension(self):
+        descriptor = self.make_descriptor(indices=(2, 3, 4))
+
+        with tempfile.TemporaryDirectory() as tmpdir:
+            self.write_complete_sidecar_set(tmpdir, "mkv")
+            result = descriptor.importSubtitles(
+                tmpdir,
+                "A2_t01",
+                extension=".mkv",
+                strict=True,
+            )
+
+        self.assertEqual(3, result["candidate_count"])
+        self.assertEqual([2, 3, 4], result["imported_track_indices"])
+        self.assertEqual([], result["missing_track_indices"])
+        self.assertTrue(
+            all(
+                track.getExternalSourceFilePath().endswith(".mkv")
+                for track in descriptor.getSubtitleTracks()
+            )
+        )
+
+    def test_strict_basename_import_reports_missing_tracks(self):
+        descriptor = self.make_descriptor(indices=(2, 3, 4))
+
+        with tempfile.TemporaryDirectory() as tmpdir:
+            sidecarPath = Path(tmpdir) / "episode_2_deu.vtt"
+            sidecarPath.write_text("WEBVTT\n\n", encoding="utf-8")
+
+            result = descriptor.importSubtitles(
+                tmpdir,
+                "episode",
+                strict=True,
+            )
+
+        self.assertEqual([2], result["imported_track_indices"])
+        self.assertEqual([3, 4], result["missing_track_indices"])
+
+    def test_strict_basename_import_rejects_too_many_files(self):
+        descriptor = self.make_descriptor(indices=(2,))
+
+        with tempfile.TemporaryDirectory() as tmpdir:
+            for filename in ("episode_2_deu.vtt", "episode_3_eng.vtt"):
+                (Path(tmpdir) / filename).write_text("WEBVTT\n\n", encoding="utf-8")
+
+            with self.assertRaisesRegex(ValueError, "2 matching .* for 1 subtitle tracks"):
+                descriptor.importSubtitles(tmpdir, "episode", strict=True)
+
+    def test_strict_basename_import_rejects_unknown_track_index(self):
+        descriptor = self.make_descriptor(indices=(2, 3, 4))
+
+        with tempfile.TemporaryDirectory() as tmpdir:
+            (Path(tmpdir) / "episode_9_eng.vtt").write_text(
+                "WEBVTT\n\n",
+                encoding="utf-8",
+            )
+
+            with self.assertRaisesRegex(ValueError, "track index pattern does not match"):
+                descriptor.importSubtitles(tmpdir, "episode", strict=True)
+
+    def test_strict_basename_import_rejects_malformed_filtered_filename(self):
+        descriptor = self.make_descriptor(indices=(2, 3, 4))
+
+        with tempfile.TemporaryDirectory() as tmpdir:
+            (Path(tmpdir) / "episode_s01e01_2_deu.vtt").write_text(
+                "WEBVTT\n\n",
+                encoding="utf-8",
+            )
+
+            with self.assertRaisesRegex(ValueError, "expected pattern"):
+                descriptor.importSubtitles(tmpdir, "episode", strict=True)
+
+    def test_strict_basename_import_rejects_duplicate_track_indices(self):
+        descriptor = self.make_descriptor(indices=(2, 3, 4))
+
+        with tempfile.TemporaryDirectory() as tmpdir:
+            for filename in ("episode_2_deu.vtt", "episode_2_eng.vtt"):
+                (Path(tmpdir) / filename).write_text("WEBVTT\n\n", encoding="utf-8")
+
+            with self.assertRaisesRegex(ValueError, "Multiple external subtitle files"):
+                descriptor.importSubtitles(tmpdir, "episode", strict=True)
+
 
 if __name__ == "__main__":
     unittest.main()

tests/unit/test_pattern_management.py

@@ -193,6 +193,36 @@ class PatternManagementTests(unittest.TestCase):
 
         self.assertIn("at least one track", str(caught.exception))
 
+    def test_save_pattern_schema_does_not_persist_attachment_tracks(self):
+        pattern_id = self.save_pattern(
+            1,
+            r"^noattachments_(s[0-9]+e[0-9]+)\.mkv$",
+            tracks=[
+                make_track_descriptor(0, track_type=TrackType.VIDEO),
+                make_track_descriptor(1, track_type=TrackType.ATTACHMENT),
+            ],
+        )
+
+        Session = self.context["database"]["session"]
+        session = Session()
+        try:
+            tracks = session.query(Pattern).filter(Pattern.id == pattern_id).first().tracks
+            self.assertEqual(1, len(tracks))
+            self.assertEqual(TrackType.VIDEO, tracks[0].getType())
+        finally:
+            session.close()
+
+    def test_track_controller_does_not_add_attachment_tracks_to_patterns(self):
+        pattern_id = self.save_pattern(1, r"^skipadd_(s[0-9]+e[0-9]+)\.mkv$")
+
+        added = self.track_controller.addTrack(
+            make_track_descriptor(1, track_type=TrackType.ATTACHMENT),
+            patternId=pattern_id,
+        )
+
+        self.assertFalse(added)
+        self.assertEqual(1, len(self.track_controller.findTracks(pattern_id)))
+
     def test_match_filename_rejects_existing_trackless_pattern_rows(self):
         self.insert_trackless_pattern_row(1, r"^invalid_(s[0-9]+e[0-9]+)\.mkv$")
 

tests/unit/test_tag_table_screen_state.py

@@ -15,12 +15,13 @@ if str(SRC_ROOT) not in sys.path:
 
 from ffx.audio_layout import AudioLayout  # noqa: E402
 from ffx.attachment_format import AttachmentFormat  # noqa: E402
-from ffx.helper import DIFF_ADDED_KEY  # noqa: E402
+from ffx.helper import DIFF_ADDED_KEY, DIFF_REMOVED_KEY  # noqa: E402
 from ffx.iso_language import IsoLanguage  # noqa: E402
 from ffx.logging_utils import get_ffx_logger  # noqa: E402
 from ffx.inspect_details_screen import InspectDetailsScreen  # noqa: E402
 from ffx.i18n import set_current_language  # noqa: E402
 from ffx.media_descriptor import MediaDescriptor  # noqa: E402
+from ffx.media_descriptor_change_set import MediaDescriptorChangeSet  # noqa: E402
 from ffx.media_edit_screen import MediaEditScreen  # noqa: E402
 from ffx.pattern_details_screen import PatternDetailsScreen  # noqa: E402
 from ffx.show_descriptor import ShowDescriptor  # noqa: E402
@@ -822,6 +823,89 @@ class TagTableScreenStateTests(unittest.TestCase):
         self.assertEqual("unknown", row[3])
         self.assertEqual(" ", row[5])
 
+    def test_inspect_details_screen_uses_source_font_attachments_for_styled_ass(self):
+        class _Config:
+            def getData(self):
+                return {}
+
+        class _Pattern:
+            def __init__(self, media_descriptor):
+                self._media_descriptor = media_descriptor
+
+            def getMediaDescriptor(self, _context):
+                return self._media_descriptor
+
+        source_descriptor = MediaDescriptor(
+            track_descriptors=[
+                TrackDescriptor(
+                    index=0,
+                    source_index=0,
+                    sub_index=0,
+                    track_type=TrackType.SUBTITLE,
+                    codec_name=TrackCodec.ASS,
+                    tags={"title": "Styled Subtitle"},
+                ),
+                TrackDescriptor(
+                    index=1,
+                    source_index=1,
+                    sub_index=0,
+                    track_type=TrackType.ATTACHMENT,
+                    attachment_format=AttachmentFormat.TTF,
+                    tags={"filename": "current.ttf", "mimetype": "font/ttf"},
+                ),
+            ]
+        )
+        pattern_descriptor = MediaDescriptor(
+            track_descriptors=[
+                TrackDescriptor(
+                    index=0,
+                    source_index=0,
+                    sub_index=0,
+                    track_type=TrackType.SUBTITLE,
+                    codec_name=TrackCodec.ASS,
+                    tags={"title": "Styled Subtitle"},
+                ),
+                TrackDescriptor(
+                    index=1,
+                    source_index=1,
+                    sub_index=0,
+                    track_type=TrackType.ATTACHMENT,
+                    attachment_format=AttachmentFormat.TTF,
+                    tags={"filename": "old.ttf", "mimetype": "font/ttf"},
+                ),
+                TrackDescriptor(
+                    index=2,
+                    source_index=2,
+                    sub_index=1,
+                    track_type=TrackType.ATTACHMENT,
+                    attachment_format=AttachmentFormat.TTF,
+                    tags={"filename": "missing.ttf", "mimetype": "font/ttf"},
+                ),
+            ]
+        )
+
+        screen = object.__new__(InspectDetailsScreen)
+        screen.context = {"logger": get_ffx_logger(), "config": _Config()}
+
+        resolved_descriptor = screen._resolve_target_media_descriptor(
+            _Pattern(pattern_descriptor),
+            source_descriptor,
+        )
+        attachment_tracks = resolved_descriptor.getAttachmentTracks()
+
+        self.assertEqual(1, len(attachment_tracks))
+        self.assertEqual({"filename": "current.ttf", "mimetype": "font/ttf"}, attachment_tracks[0].getTags())
+
+        change_set = MediaDescriptorChangeSet(
+            screen.context,
+            resolved_descriptor,
+            source_descriptor,
+        ).getChangeSetObj()
+        self.assertNotIn(
+            1,
+            change_set.get("tracks", {}).get(DIFF_REMOVED_KEY, {}),
+        )
+
     def test_inspect_details_screen_maps_target_selection_back_to_source_track(self):
         source_track = TrackDescriptor(
             index=3,