forked from unom/punktfunk
enricobuehlerandClaude Opus 5
6af067da2d
A user's 1080p stream repeated its last row of pixels over the final few rows, so the image looked stretched at the bottom. The Vulkan-Video CSC pass sampled the decoded planes with the fullscreen triangle's normalized 0..1 UVs, but its render target is built at the CROPPED frame size. Those are not the same rectangle: FFmpeg sizes the decode pool from `avctx->coded_*`, and H.264 codes `16 * mb_height` — so a 1080-row picture decodes into a 1088-row pool. Destination row 1079 sampled source row ~1087.5, dragging the 8 alignment rows into view and squashing the picture 0.7%. Encoders fill that padding by replicating the last picture line, which is why it reads as a smeared bottom row rather than garbage. Confirmed on glass (.173, RTX, H.264 1080p, vulkan-video): Vulkan Video first frame width=1920 height=1080 pool_w=1920 pool_h=1088 `VkVideoFrame` now carries the pool extent and `record_csc` takes a `uv_scale`, written to the shader's `params.zw` — which the CSC shader already reserved for a use like this. The chroma cositing offset is unchanged and stays correct: `textureSize` reports the pool width, which is the space the scaled UV is already in. Only the Vulkan-Video path passes a scale below 1.0. D3D11VA already clamps this in its VideoProcessor blit (the same bug, seen as a green bar there because DXVA padding is uninitialized rather than replicated); dmabuf imports its planes at the crop over the real stride; PyroWave allocates its ring at exact stream dims. Apple and Android crop at the OS layer. Every other call site passes [1.0, 1.0], so the change is inert there. Also adds a one-time first-frame layout log mirroring the D3D11VA one, so the frame-vs-pool gap is visible in the field instead of having to be re-derived from FFmpeg internals. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>