fix(softimage): support channel packets with differing bit depths#5309
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fix(softimage): support channel packets with differing bit depths#5309lgritz wants to merge 1 commit into
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A Softimage PIC file stores a chain of channel packets, each carrying its own bit depth (8 or 16). The reader assumed one uniform per-channel size for the whole image, so a file mixing depths (e.g. 16-bit R with 8-bit G) wrote past the end of the scanline buffer -- a heap overflow reachable via iconvert poc.pic -o out.exr. Fix: always expose one uniform pixel format, the widest depth among the file's packets, and promote narrower channels to it on read via exact bit replication (v*257 for 8->16), which preserves the normalized value exactly. This keeps the pixel layout naturally aligned; representing channels with their true differing formats instead would pack them at non-uniform, sometimes misaligned byte offsets. Assisted-by: Claude Code / claude-sonnet-5 Signed-off-by: Larry Gritz <lg@larrygritz.com>
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A Softimage PIC file stores a chain of channel packets, each carrying its own bit depth (8 or 16). The reader assumed one uniform per-channel size for the whole image, so a file mixing depths (e.g. 16-bit R with 8-bit G) wrote past the end of the scanline buffer.
Fix: always expose one uniform pixel format, the widest depth among the file's packets, and promote narrower channels to it on read via exact bit replication (v*257 for 8->16), which preserves the normalized value exactly. This keeps the pixel layout naturally aligned; representing channels with their true differing formats instead would pack them at non-uniform, sometimes misaligned byte offsets.
Assisted-by: Claude Code / claude-sonnet-5