- The two halves of each stream are independent bit streams: they now decode in parallel
(`decode_stream`) instead of one after the other inside each of a tile's 13 streams.
- The vertical inverse 5/3 runs its rows in parallel. The horizontal pass lifts each row in place
(`lift_row`, scratch space reused per thread), rows in parallel, instead of allocating two vectors
per row and copying the result back; a test checks it against the vertical pass, row by row.
Best of 3 on 4 CPUs, previous and new decoder alternating: ILCE-7RM6 FF HQ 0.60 → 0.48 s
(process CPU 1.14 → 0.87 s), FF Compressed 0.62 → 0.48 s, APS-C HQ 0.34 → 0.23 s, APS-C
Compressed 0.31 → 0.24 s (docs/arw6-compression.md → Timings). The decoded mosaic is identical
(hash of every sample) on the 8 ARW6 files of the RawDB ILCE-7RM6 set and 3 private A7R VI photos.
Co-Authored-By: Claude <noreply@anthropic.com>
