[camera_android_x] Refactor ImageProxyUtils.planesToNV21 to prevent buffer issues #10163
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…ve UV plane mocking
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| List<PlaneProxy> planes = Arrays.asList(yPlane, uPlane, vPlane); | ||
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| ByteBuffer nv21Buffer = ImageProxyUtils.planesToNV21(planes, width, height); |
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1280x720 → ~4.6 ms per frame. Further evaluation is needed to assess the impact on the processing pipeline.
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@Mairramer two things -- First, can you possibly update to the PR description to describe how you came to these changes? I'm not an expert in the conversion so it would help me review this PR. Second, I assumed the fix would be using this logic I left out initially: Thoughts on that versus your approach? |
While this approach is valid, it still encounters the same issue when checking areUVPlanesNV21(). My implementation essentially replicates part of the unpackPlane() logic, avoiding assumptions about the U/V buffer layout and ensuring a deterministic NV21 output. Additionally, it leverages CameraX’s internal ImageUtil Both approaches perform a complete manual reconstruction of the image, guaranteeing correctness regardless of how the U/V planes are arranged. I am still investigating why position == limit occurs in some CameraX buffers. Understanding this behavior could help refine the reconstruction logic. |
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My only concern is the per-frame processing time. |
This change replaces the previous
planesToNV21()implementation with a direct and stride-aware conversion.The prior version assumed that the U and V planes followed the same layout used by Camera2, which is not always true for CameraX. This assumption could cause color distortion or corrupted frames because CameraX applies internal transformations (rotation, cropping, or proxy wrapping) that modify rowStride, pixelStride, and overall buffer layout.
After investigating inconsistencies between the original
areUVPlanesNV21()-based logic and the actual ImageProxy buffers returned by CameraX, this version explicitly reconstructs NV21 by reading each plane row by row while respecting their individual strides, rather than simply validating whether the format already matchesNV21.Fixes flutter/flutter#176410
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