From 15761070d1cdc622ffbc5d6aeb0a50e063361012 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Tomas=20H=C3=A4rdin?= Date: Tue, 14 Jun 2022 11:19:06 +0200 Subject: [PATCH 12/13] lavc/jpeg2000dec: Use coarser slicing for initial reslevels This brings -lowres 2 lossless 4K J2K on an AMD EPYC 7R32 to 52 fps (2080% CPU). --- libavcodec/jpeg2000dec.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c index a2b9f0166b..18ebe5219d 100644 --- a/libavcodec/jpeg2000dec.c +++ b/libavcodec/jpeg2000dec.c @@ -2679,7 +2679,16 @@ static int jpeg2000_decode_frame(AVCodecContext *avctx, AVFrame *picture, for (s->reslevel = 0; s->reslevel < maxreslevels; s->reslevel++) { for (s->dir = 0; s->dir < 2; s->dir++) { + int before = s->slices; + int div = s->slices >= 96 ? 7 : 5; + + if (s->reslevel < div) { + int halve = 1<<(div - s->reslevel + (s->slices >= 96 ? 0 : 1 - s->dir)); + s->slices = (s->slices + halve-1)/halve; + } + avctx->execute2(avctx, jpeg2000_idwt, NULL, NULL, s->numXtiles * s->numYtiles * s->ncomponents * s->slices); + s->slices = before; } } -- 2.30.2