Media Foundation H.264 Hardware Fixture

This is an offline Windows-only decision fixture. Its build compiles the same Media Foundation encoder source used by Piik App's Windows capture process, under a fixture-only macro for synthetic input and telemetry. The generated fixture is not linked into the sender and does not contact a room, signaling service, Viewer, or production endpoint.

The fixture selects one DXGI adapter and one adapter-bound Media Foundation transform. It never enumerates a software MFT and has no codec or software fallback. Exit code zero requires all of these checks in one 360-frame run:

adapter-LUID-bound hardware H.264 enumeration;
asynchronous and D3D11-aware transform readback;
exact low-latency, CBR, 3 Mbps, one-frame VBV, and 60-frame GOP property readback, plus Baseline media-type request/readback and output-order no-reordering checks;
360 GPU-surface NV12 inputs and 360 ordered outputs;
one live 3 Mbps -> 1.5 Mbps -> 3 Mbps rate change whose three equal phases lower and then restore actual encoded bytes without recreating the MFT;
Annex-B SPS/PPS/IDR at frames 0, 60, 120, 180, 240, and 300;
an SPS profile-level-id exactly present in the fixture's default Pion mode-1 fmtp set; and
process-and-adapter-attributed Windows VideoEncode activity.

The generated executable must stay outside the repository. From PowerShell:

$out = Join-Path ([IO.Path]::GetTempPath()) 'piik-mf-h264-fixture-build'
./native/fixtures/mf-h264-hardware/build.ps1 -OutputDirectory $out
& "$out/piik-mf-h264-fixture.exe" --list-adapters
& "$out/piik-mf-h264-fixture.exe" --adapter-index 0 --mft-index 0

Select the adapter index explicitly from the first command. The MFT index defaults to zero but is printed and accepted explicitly so a retained run cannot silently switch transforms.

The fixture prints bounded key/value evidence to stdout and never writes the encoded bitstream. A nonzero exit is a measured no-go at the reported stage; it must not be worked around by adding a software retry.

Pion transport and browser decode remain separate from this offline fixture; the product path reuses its exact 42c01f, Annex-B, adapter-bound hardware contract without adding those network concerns to this executable.

Primary API references, accessed 2026-08-20: