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
New backend in crates/platform (media_foundation/): a Direct3D-aware decoder MFT is driven at the
level of single access units (Annex B), given the process's D3D11 video device through an
IMFDXGIDeviceManager so it decodes with DXVA, and its NV12 / P010 textures are read back through a
staging texture into planar Yuv8 / Yuv16. H.264 Baseline/Main/High and HEVC Main / Main 10, 4:2:0.
- Hardware is verified: non-D3D-aware or async MFTs, streams the GPU's DXVA decoder does not list,
and system-memory output (Microsoft's MFT software fallback) are declined or fail the stream so
HybridDecoder continues with our decoder.
- mfplat.dll is loaded at run time so Windows N editions still start.
- register() / registered() / hardware_decoder_for() cover Windows; perf.stats reports the backend.
- Tests (Windows): bit-exact parity with the software decoders at 640x360, 1080p and 2160p
(resets, seeks, flush), forced mid-stream failure, damaged input, concurrency, repeated init.
- Bench: runs on Windows (ffmpeg on PATH, process/thread CPU clocks), HEVC Main 10 2160p row,
hardware counters per row.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MMorBHwct72udS2LiC3ZHp
Davi Andrei