avcodec/scpr: Use av_memcpy_backptr() in type 17 and 33

This makes the changed code-path faster.

Change not tested except with the fuzzer testcase as I found no other testcase.

Improves: Timeout (136sec -> 74sec)
Improves: 16040/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_SCPR_fuzzer-5705876062601216

Reviewed-by: Paul B Mahol <onemda@gmail.com>
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
This commit is contained in:
Michael Niedermayer 2019-07-30 00:52:18 +02:00
parent 1fedba3c35
commit 950a21e83c

View File

@ -532,7 +532,7 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
s->current_frame->linesize[0] / 4);
} else if (type == 17 || type == 33) {
uint32_t clr, *dst = (uint32_t *)s->current_frame->data[0];
int x, y;
int y;
frame->key_frame = 1;
bytestream2_skip(gb, 1);
@ -548,9 +548,8 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
clr = bytestream2_get_le24(gb);
}
for (y = 0; y < avctx->height; y++) {
for (x = 0; x < avctx->width; x++) {
dst[x] = clr;
}
dst[0] = clr;
av_memcpy_backptr((uint8_t*)(dst+1), 4, 4*avctx->width - 4);
dst += s->current_frame->linesize[0] / 4;
}
} else if (type == 0 || type == 1) {