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mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-23 12:43:46 +02:00

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 <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2019-08-02 23:10:35 +02:00
parent 34f6d1a7d7
commit 5231e89eb9

View File

@ -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--;