Imported video is a Group[Video, Audio] that rendered as a Vello-baked
Vector layer, re-uploading the full frame to Vello's image atlas every
frame (~17ms/frame at 1080p, hitting playback and export alike). Extract
video frames out of the Group/clip scene recursion into
VideoRenderInstances so they composite via the GPU Video path; mixed
video+vector containers fall back to Vello (correct, unaccelerated).
Also route video through hardware sRGB decode: upload raw sRGB bytes to an
Rgba8UnormSrgb texture and blit with a non-unpremultiplying shader variant
(blit_straight), removing the per-frame per-pixel CPU sRGB->linear pass.
Add an F3 GPU-timestamp timer and a per-frame video texture cache.
Drops the live composite of a 1080p video from ~17ms to ~2-3ms.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Skyler Lehmkuhl