v0.3.1

tests/support/ffx_bundle.py

@@ -7,6 +7,7 @@ import os
 from pathlib import Path
 import subprocess
 import sys
+from functools import lru_cache
 from typing import Mapping
 
 
@@ -95,6 +96,45 @@ def write_vtt(path: Path, lines: tuple[str, ...]) -> Path:
     return path
 
 
+@lru_cache(maxsize=None)
+def _ffmpeg_encoder_is_available(encoder_name: str) -> bool:
+    completed = subprocess.run(
+        ["ffmpeg", "-encoders"],
+        capture_output=True,
+        text=True,
+    )
+    if completed.returncode != 0:
+        return False
+
+    encoder_label = str(encoder_name).strip()
+    for line in completed.stdout.splitlines():
+        if not line.startswith(" "):
+            continue
+
+        tokens = line.split(maxsplit=2)
+        if len(tokens) >= 2 and tokens[1] == encoder_label:
+            return True
+
+    return False
+
+
+def _resolve_fixture_video_encoder(
+    video_encoder: str,
+    video_encoder_options: tuple[str, ...],
+) -> tuple[str, tuple[str, ...]]:
+    if video_encoder != "libx264":
+        return video_encoder, video_encoder_options
+
+    if _ffmpeg_encoder_is_available("libx264"):
+        return video_encoder, video_encoder_options
+
+    if _ffmpeg_encoder_is_available("libopenh264"):
+        # Keep fixture generation software-based when libx264 is missing.
+        return "libopenh264", ("-pix_fmt", "yuv420p")
+
+    return video_encoder, video_encoder_options
+
+
 def create_source_fixture(
     workdir: Path,
     filename: str,
@@ -115,6 +155,10 @@ def create_source_fixture(
     subtitle_encoder: str = "webvtt",
 ) -> Path:
     output_path = workdir / filename
+    video_encoder, video_encoder_options = _resolve_fixture_video_encoder(
+        video_encoder,
+        video_encoder_options,
+    )
 
     has_video = any(track.track_type == TrackType.VIDEO for track in tracks)
     has_audio = any(track.track_type == TrackType.AUDIO for track in tracks)

tests/unit/test_ffx_controller.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import click
 from pathlib import Path
 import sys
 import unittest
@@ -32,6 +33,9 @@ class StaticConfig:
 
 
 class FfxControllerTests(unittest.TestCase):
+    def tearDown(self):
+        FfxController.isFfmpegEncoderAvailable.cache_clear()
+
     def make_context(self, video_encoder: VideoEncoder) -> dict:
         return {
             "logger": get_ffx_logger(),
@@ -192,6 +196,62 @@ class FfxControllerTests(unittest.TestCase):
         self.assertIn("ENCODING_QUALITY=19", commands[0])
         mocked_info.assert_any_call("Setting quality 19 from pattern")
 
+    def test_generate_h264_tokens_prefers_libx264_when_available(self):
+        context = self.make_context(VideoEncoder.H264)
+        target_descriptor, source_descriptor = self.make_media_descriptors()
+        controller = FfxController(context, target_descriptor, source_descriptor)
+
+        with patch.object(
+            FfxController,
+            "getSupportedSoftwareH264Encoder",
+            return_value="libx264",
+        ):
+            tokens = controller.generateH264Tokens(23)
+
+        self.assertEqual(
+            ["-c:v:0", "libx264", "-preset", "slow", "-crf", "23"],
+            tokens,
+        )
+
+    def test_generate_h264_tokens_falls_back_to_libopenh264_and_logs_warning(self):
+        context = self.make_context(VideoEncoder.H264)
+        target_descriptor, source_descriptor = self.make_media_descriptors()
+        controller = FfxController(context, target_descriptor, source_descriptor)
+
+        with (
+            patch.object(
+                FfxController,
+                "getSupportedSoftwareH264Encoder",
+                return_value="libopenh264",
+            ),
+            patch.object(context["logger"], "warning") as mocked_warning,
+        ):
+            tokens = controller.generateH264Tokens(23)
+
+        self.assertEqual(
+            ["-c:v:0", "libopenh264", "-pix_fmt", "yuv420p"],
+            tokens,
+        )
+        mocked_warning.assert_called_once_with(
+            "libx264 encoder unavailable; falling back to libopenh264 for H.264 encoding."
+        )
+
+    def test_generate_h264_tokens_raises_when_no_supported_software_encoder_exists(self):
+        context = self.make_context(VideoEncoder.H264)
+        target_descriptor, source_descriptor = self.make_media_descriptors()
+        controller = FfxController(context, target_descriptor, source_descriptor)
+
+        with patch.object(
+            FfxController,
+            "getSupportedSoftwareH264Encoder",
+            return_value=None,
+        ):
+            with self.assertRaisesRegex(
+                click.ClickException,
+                "no supported software H.264 encoder is available",
+            ):
+                controller.generateH264Tokens(23)
+
 
 if __name__ == "__main__":
     unittest.main()