vangel76andClaude Opus 5.5 ce63803934 #980: VP9 decode loop-filters a frame as a superblock-row wavefront ...

Problem: the post stage of a VP9 frame (band assembly, loop filter,
publication) ran on one thread. Later frames wait per band for their
references, so the serial loop filter (~30 % of the profile) set the
pace of every inter frame; 16 threads were only ~1.8x one thread.

Fix: rows of a frame's loop filter run as a wavefront, row r two
superblocks behind row r - 1 (what the raster order of 8.8.1 allows),
taken by the post thread and helper jobs on the decoder's pool. No lock
is held while a superblock is filtered: each row filters its own band
and rows exchange copies of the 8 rows the filter reaches across a band
boundary. Output stays bit-identical; one thread / wasm run the rows in
order as before. A row is only taken by a running thread, so waits
always make progress, and helpers run under catch_unwind (a failure
publishes placeholder bands as before). New conformance fixture
narrow_tall (2 superblock columns) and a repeated multi-thread 1080p
decode test. 1.2-1.5x faster with 16 threads on a shared machine.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

2026-10-11 10:18:44 +02:00

..

common

#980: VP9 decode loop-filters a frame as a superblock-row wavefront

2026-10-11 10:18:44 +02:00

conformance.rs

#980: VP9 decode loop-filters a frame as a superblock-row wavefront

2026-10-11 10:18:44 +02:00

perf.rs

M4.10: VP9 frame threading (band-published references, per-frame post stage) and draft mode

2026-10-03 05:34:39 -04:00

robustness.rs

M9.8: VP9 fixture matrix with backward adaptation / alt-ref / tile rows, synthetic scaled-reference, intra-only and show_existing streams, robustness tests

2026-09-30 22:37:46 -04:00

synthetic.rs

M9.8: VP9 fixture matrix with backward adaptation / alt-ref / tile rows, synthetic scaled-reference, intra-only and show_existing streams, robustness tests

2026-09-30 22:37:46 -04:00