From 5231e89eb9eedc119d4f762469355f83e3628f20 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Fri, 2 Aug 2019 23:10:35 +0200 Subject: [PATCH] avcodec/pictordec: Optimize picmemset() for single plane full lines Fixes: Timeout (72sec -> 1sec) Fixes: 15512/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_PICTOR_fuzzer-5663942342344704 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/pictordec.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/libavcodec/pictordec.c b/libavcodec/pictordec.c index 2e6fcdca52..6340902526 100644 --- a/libavcodec/pictordec.c +++ b/libavcodec/pictordec.c @@ -66,6 +66,7 @@ static void picmemset(PicContext *s, AVFrame *frame, unsigned value, int run, int xl = *x; int yl = *y; int planel = *plane; + int pixels_per_value = 8/bits_per_plane; value <<= shift; d = frame->data[0] + yl * frame->linesize[0]; @@ -74,7 +75,7 @@ static void picmemset(PicContext *s, AVFrame *frame, unsigned value, int run, for (j = 8-bits_per_plane; j >= 0; j -= bits_per_plane) { d[xl] |= (value >> j) & mask; xl += 1; - if (xl == s->width) { + while (xl == s->width) { yl -= 1; xl = 0; if (yl < 0) { @@ -86,6 +87,19 @@ static void picmemset(PicContext *s, AVFrame *frame, unsigned value, int run, mask <<= bits_per_plane; } d = frame->data[0] + yl * frame->linesize[0]; + if (s->nb_planes == 1 && + run*pixels_per_value >= s->width && + pixels_per_value < s->width && + s->width % pixels_per_value == 0 + ) { + for (; xl < pixels_per_value; xl ++) { + j = (j < bits_per_plane ? 8 : j) - bits_per_plane; + d[xl] |= (value >> j) & mask; + } + av_memcpy_backptr(d+xl, pixels_per_value, s->width - xl); + run -= s->width / pixels_per_value; + xl = s->width; + } } } run--;