Module ffmpeg 

Video encoding via ffmpeg subprocess (matches Playwright’s approach).

Spawns ffmpeg CLI and pipes JPEG frames to stdin. No compile-time ffmpeg/libav dependency – the binary just needs ffmpeg on PATH at runtime when --video is used.

Codec selection matches Playwright: VP8/WebM by default, fallback to libx264/MP4 if VP8 is unavailable.

Functions

encode_frames

Batch encode: pipe all frames at once (for deferred/buffered recording).

encode_stream

Channel-driven encoding: pipe JPEG frames to ffmpeg subprocess as they arrive. Runs on a blocking thread concurrently with the test.

video_content_type

Return the correct MIME type based on available encoder.

video_extension

Return the correct file extension based on available encoder.