ffmpeg keeps a trailing zero byte after the hvcC PPS that the in-band PPS lacks, so the byte-for-byte comparison read it as a parameter-set change and sent the stream to the software decoder from its first sample. A NAL unit never ends with 0x00 (H.264 7.4.1, H.265 7.4.2): those bytes are trailing_zero_8bits, so both sides are compared without them. The platform fallback test used a trailing zero byte as its changed SPS; it now changes nal_ref_idc.
vui_color took the VUI matrix, transfer and range but not the primaries,
so every decoded H.264 / HEVC frame reported BT.709 primaries. Stream info
read them, so a BT.2020 file without a colr box said BT.2020 in its info
and BT.709 on its frames (Rec709 instead of Rec2020 for the renderer).
Pass colour_primaries through, for the software and hardware decoders.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
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
- New crates/platform (filmcraft-platform, L5): OS media FFI only. The one
crate allowed `unsafe` (own [lints] with unsafe_code = "deny",
#[allow(unsafe_code)] only on the videotoolbox module, SAFETY comment on
every block, safe Result-returning public API). AGENTS.md §0.3 names the
exception; docs/adr/0001-platform-ffi.md records why and the rules.
- VideoToolbox decoder for avcC / hvcC, 8/10-bit 4:2:0 and 4:2:2: session from
the sample entry's parameter sets with hardware required, asynchronous
decode (2 in flight), biplanar CVPixelBuffer copied to planar Yuv8/Yuv16,
reorder buffer of the stream's own depth, RASL skipped after a starting CRA.
Output callback under catch_unwind.
- HybridDecoder: transparent mid-stream fallback to the software decoder
(replays samples since the last restart point, drops already-returned
pictures). New codecs::software_video_decoder (built-in factories only) and
codecs::hw (switch, counters, NalStreamInfo shared with software decoders;
vui_color / sar_par helpers now used by both).
- Settings ▸ Playback ▸ Hardware decoding: Auto / Off (engine applies it to
the codecs switch); desktop app, CLI/MCP and bench call register().
- perf.stats decode.framesDecoded and decode.hardware counters.
- Tests: bit-exact parity with the software decoders (H.264 High, HEVC Main
open GOP, Main 10; resets, reseeks, flushes), forced-failure fallback,
mutation fuzz of samples and parameter sets, cross-platform fallback with a
stand-in decoder, setting Off, HEVC 4:2:2 vs ffmpeg.
- Bench --hw auto|off; results in docs/performance.md (4K CPU/frame
~86-119 ms -> ~4 ms).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Marco Arnulfo
JordyUSA
Davi Andrei
Brandon Thomas