[FFmpeg-devel] [PATCH 4/6] avcodec/lagarith: Optimize FRAME_SOLID_RGBA

[Carl Eugen Hoyos]

2018-08-13 2:24 GMT+02:00, Michael Niedermayer <michael at niedermayer.cc>:
> Fixes: Timeout
> Fixes:
> 9484/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_LAGARITH_fuzzer-5707859156271104
>
> Found-by: continuous fuzzing process
> https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> ---
>  libavcodec/lagarith.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/libavcodec/lagarith.c b/libavcodec/lagarith.c
> index 510a6ff2d6..b9a0649c31 100644
> --- a/libavcodec/lagarith.c
> +++ b/libavcodec/lagarith.c
> @@ -572,8 +572,14 @@ static int lag_decode_frame(AVCodecContext *avctx,
>
>          dst = p->data[0];
>          if (frametype == FRAME_SOLID_RGBA) {
> +            int w2 = avctx->width>>2;

qwidth? w2 is hard to read imo.

> +            uint64_t c = ((uint64_t)offset_gu << 32) | offset_gu;
>          for (j = 0; j < avctx->height; j++) {
> -            for (i = 0; i < avctx->width; i++)
> +            for (i = 0; i < w2; i++) {
> +                AV_WN64(dst + i * 16    , c);
> +                AV_WN64(dst + i * 16 + 8, c);
> +            }
> +            for (i = 4*w2; i < avctx->width; i++)

And please add (very) rough numbers to the commit message.

Thank you, Carl Eugen