From 981f04b2ae2d6e0355386aaff39840eb5d390a36 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Fri, 8 Sep 2017 23:29:13 +0200 Subject: [PATCH] avcodec/scpr: optimize shift loop. Speeds code up from 50sec to 15sec Fixes Timeout Fixes: 3242/clusterfuzz-testcase-5811951672229888 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Reviewed-by: James Almer Signed-off-by: Michael Niedermayer --- libavcodec/scpr.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/libavcodec/scpr.c b/libavcodec/scpr.c index 37fbe7a106..cbe1bc40d9 100644 --- a/libavcodec/scpr.c +++ b/libavcodec/scpr.c @@ -826,8 +826,19 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, if (ret < 0) return ret; + // scale up each sample by 8 for (y = 0; y < avctx->height; y++) { - for (x = 0; x < avctx->width * 4; x++) { + // If the image is sufficiently aligned, compute 8 samples at once + if (!(((uintptr_t)dst) & 7)) { + uint64_t *dst64 = (uint64_t *)dst; + int w = avctx->width>>1; + for (x = 0; x < w; x++) { + dst64[x] = (dst64[x] << 3) & 0xFCFCFCFCFCFCFCFCULL; + } + x *= 8; + } else + x = 0; + for (; x < avctx->width * 4; x++) { dst[x] = dst[x] << 3; } dst += frame->linesize[0];