The zero-copy VAAPI encoder emitted full-range BT.709 NV12 but wrote no color
tags, so players assumed limited range and stretched it — the H.264 output
looked dark and oversaturated (preview and VP9/software were fine).
- Rgba2Nv12 takes `full_range` and applies the matching Y/chroma scale+offset
(limited 16-235 / full 0-255) via a uniform; the encoder sets color_range +
bt709 colorspace/primaries/transfer tags to match. ffprobe-confirmed.
- New ColorRange { Limited, Full } on VideoExportSettings (default Limited, the
universally-correct choice; serde(default) so saved settings still load),
surfaced as a "Color range" dropdown in advanced export settings for H.264.
The swscale software fallback still emits Limited regardless of the toggle
(Full only affects the VAAPI zero-copy path).
ZeroCopyEncoder::new now takes an output path and writes a real container
(format inferred from the extension, e.g. .mp4): create an output format
context, add the h264 stream from the encoder, write header; encode_rgba
rescales each packet's ts and av_interleaved_write_frame's it; finish
flushes + writes the trailer + closes. Sets AV_CODEC_FLAG_GLOBAL_HEADER for
mp4/mov so SPS/PPS land in extradata. This lets the editor's existing
mux_video_and_audio consume the temp video file unchanged.
The zerocopy_encode test now writes a .mp4 and ffprobe-verifies the codec,
dimensions, and frame count. Also let wgpu own the imported plane-image
destruction via texture_from_raw drop callbacks (clears two warnings).
Build the full end-to-end zero-copy encoder, validated on Intel/VAAPI:
- render_nv12: fragment-shader RGBA->NV12 that renders luma/chroma into
the imported R8/RG8 plane render targets (compute storage can't write
the DMA-BUF-backed planes; render attachments can).
- dmabuf: import_raw imports an NV12 DMA-BUF by explicit layout; the two
plane images + shared memory are now destroyed by wgpu via texture_from_raw
drop callbacks (Arc MemoryGuard frees the memory once both images are
gone, in wgpu's wait-idle'd deferred pass) -- fixes the teardown segfault.
- encoder::ZeroCopyEncoder: renders an RGBA texture straight into a pooled
VAAPI surface (imports cached by VASurface id) and encodes with h264_vaapi.
encode_rgba + finish; the caller renders on device().
Tests: real-frame render into the surface matches the CPU NV12 reference,
and a 30-frame encode produces valid H.264 (ffprobe-verified) with clean
teardown. Not yet wired into the editor.
Skyler Lehmkuhl