Extends the Windows backend (#141) to VP9 (profiles 0 and 2) and AV1 (main, 8/10-bit), 4:2:0.
- codecs::hw: FrameStreamInfo (vpcC / av1C): profile, bit depth, chroma, picture size and colour as
the software decoders report them (vp9_color / av1_color are now shared with them), random-access
samples, in-band format changes; StreamInfo lets HybridDecoder handle NAL and frame-coded streams.
- platform: media_foundation::stream (what each codec needs: DXVA profile, MFT request, input
format), MfDecoder generalised; VP9 frames / AV1 temporal units go in as they are; the MFT's
declared picture size (display aperture) is checked against the bitstream's.
- Declined up front: VP9 profiles 1/3, AV1 profiles 1/2, 4:2:2/4:4:4, mono, 12-bit, no codec
extension, no DXVA profile. A key frame of another size or a different sequence header falls back
to the software decoder.
- Tests: bit-exact parity (360p / 1080p / 2160p, seeks, resets, flush, hidden frames), forced
failure, damaged samples and av1C, format change fallback, WebM / Matroska through the media stack.
- Bench: AV1 fixtures with libaom when ffmpeg lacks SVT-AV1.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MMorBHwct72udS2LiC3ZHp
79cb1d0f8d