[FFmpeg-devel] [PATCH] avcodec/qpeg: Optimize long runs in qpeg_decode_intra() not spanning a full row

[Michael Niedermayer]

On Mon, Jan 07, 2019 at 08:51:33PM +0100, Paul B Mahol wrote:
> On 1/7/19, https://ieeexplore.ieee.org/document/7291728Michael
> Niedermayer <michael at niedermayer.cc> wrote:
> > On Mon, Jan 07, 2019 at 07:41:04PM +0100, Paul B Mahol wrote:
> >> On 1/7/19, Michael Niedermayer <michael at niedermayer.cc> wrote:
> >> > Fixes: Timeout
> >> > Fixes:
> >> > 11354/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_QPEG_fuzzer-5766275943366656
> >> >
> >> > Before: Executed
> >> > clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_QPEG_fuzzer-5766275943366656
> >> > in 9470 ms
> >> > After : Executed
> >> > clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_QPEG_fuzzer-5766275943366656
> >> > in  134 ms
> >> >
> >> > 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/qpeg.c | 5 ++++-
> >> >  1 file changed, 4 insertions(+), 1 deletion(-)
> >> >
> >> > diff --git a/libavcodec/qpeg.c b/libavcodec/qpeg.c
> >> > index cb452621e7..654fd998d6 100644
> >> > --- a/libavcodec/qpeg.c
> >> > +++ b/libavcodec/qpeg.c
> >> > @@ -80,7 +80,10 @@ static void qpeg_decode_intra(QpegContext *qctx,
> >> > uint8_t
> >> > *dst,
> >> >
> >> >              p = bytestream2_get_byte(&qctx->buffer);
> >> >              for(i = 0; i < run; i++) {
> >> > -                dst[filled++] = p;
> >> > +                int step = FFMIN(run - i, width - filled);
> >> > +                memset(dst+filled, p, step);
> >> > +                filled += step;
> >> > +                i      += step - 1;
> >> >                  if (filled >= width) {
> >> >                      filled = 0;
> >> >                      dst -= stride;
> >> > --
> >> > 2.20.1
> >> >
> >> > _______________________________________________
> >> > ffmpeg-devel mailing list
> >> > ffmpeg-devel at ffmpeg.org
> >> > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >> >
> >>
> >> lgtm if output does not change.
> >
> > fate-qpeg passes and it executes this codepath
> > do you have any other files i should test ?
> >
> 
> look in samples.ffmpeg.org ?

ive found and tested
qpeg-test.avi
Space.avi
Clock.avi

anything else i should test ?

thanks

[...]

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Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

The educated differ from the uneducated as much as the living from the
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