From 950a21e83c742714d6afbecd3e3fd1887e80fa40 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Tue, 30 Jul 2019 00:52:18 +0200 Subject: [PATCH] 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 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg --- libavcodec/scpr.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/libavcodec/scpr.c b/libavcodec/scpr.c index 317950dafb..dc890a87e5 100644 --- a/libavcodec/scpr.c +++ b/libavcodec/scpr.c @@ -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) {