Fix garbage preview/encode on clean-aperture sources#24
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Some sources decode to a different frame size than ffprobe reports — e.g. a 10-bit 4:2:2 ProRes file with a clean aperture: ffprobe says 720x576 (coded) but ffmpeg decodes 702x576. The worker sized raw frames from the reported dimensions, so pipe_source read 1,658,880-byte frames out of a 1,617,408-byte stream and progressively desynced, producing garbage in the preview (and the full encode) even with all filters disabled. Force the decoder to output the declared width x height (-s) in both the preview and main decode paths, so the raw stream always matches what pipe_source expects. For normal sources where decoded == coded size this is a no-op. Adds Tests/TestResources/pal-sd-25.mov (10-bit 4:2:2 ProRes, clean aperture) and a preview integration test that runs the worker in preview mode and asserts the processed frame matches a direct decode of the same source frame (mean abs diff: 102.9 before the fix, 5.9 after). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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Problem
A 10-bit 4:2:2 ProRes file showed as garbage in the processed preview even with all filters disabled.
Root cause: ffprobe reports the coded size (720×576), but ffmpeg's decoder outputs the clean aperture (702×576). The worker sized raw frames from the reported 720×576 (1,658,880 bytes/frame) while the decoded stream had 1,617,408-byte frames, so
pipe_sourceread past each frame boundary and progressively desynced → garbage. This affected the full encode too, not just preview.Fix
Force the decoder to output the declared
width×height(-s) in both decode paths (preview + main encode), so the raw stream always matches whatpipe_sourceexpects. No-op for normal sources where decoded size == coded size.Test (TDD)
Tests/TestResources/pal-sd-25.mov(10-bit 4:2:2 ProRes, clean aperture).worker/tests/preview_integration_test.rs: runs the worker in--previewmode (filters off) and asserts the processed frame matches a direct decode of the same source frame.Worker builds clean; all 49 unit tests + the new preview test pass.
Note
The fix resamples 702→720 for such sources (aligning to the coded raster the app reports everywhere) — the universally-safe fix. Using the decoded 702 natively would require the app's detection to read the clean aperture (larger change).
🤖 Generated with Claude Code