Quoting Michael Niedermayer (2021-12-06 11:35:50) > On Mon, Dec 06, 2021 at 10:25:01AM +0100, Anton Khirnov wrote: > > Quoting Michael Niedermayer (2021-12-05 22:19:01) > > > Fixes: Timeout > > > Fixes: > > > 41564/clusterfuzz-testcase-minimized-ffmpeg_dem_VIVO_fuzzer-6309014024093696 > > > > > > Found-by: continuous fuzzing process > > > https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg > > > Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc> > > > --- > > > libavformat/vivo.c | 7 ++++--- > > > 1 file changed, 4 insertions(+), 3 deletions(-) > > > > > > diff --git a/libavformat/vivo.c b/libavformat/vivo.c > > > index b2904cd25a7..8e819d910b7 100644 > > > --- a/libavformat/vivo.c > > > +++ b/libavformat/vivo.c > > > @@ -206,11 +206,12 @@ static int vivo_read_header(AVFormatContext *s) > > > return AVERROR_INVALIDDATA; > > > value_used = 1; > > > } else if (!strcmp(key, "FPS")) { > > > - AVRational tmp; > > > + double d; > > > + if (sscanf(value, "%f", &d) != 1) > > > + return AVERROR_INVALIDDATA; > > > > > > value_used = 1; > > > - if (!av_parse_ratio(&tmp, value, 10000, AV_LOG_WARNING, > > > s)) > > > - fps = av_inv_q(tmp); > > > + fps = av_d2q(1/d, 10000); > > > } > > > > > > if (!value_used) > > > -- > > > 2.17.1 > > > > Won't this be inexact? > > you mean the 1/d or in general ? > the code before used av_expr_parse_and_eval() in av_parse_ratio() so was > using floating point already. The 1/d could be done in AVRational if you > prefer? > The intermediate is inexact, the end result i would expect to be exact > as it should be the "closest" fraction with num and den below 10000 > > we also could do the whole without floating point. The actual fields > all where of the format AB.XY so 2 digits after the decimal dot. > if it was always that then its very easy to parse. But if some > oddball 3E1 or .99 something turns up that could add bugs for little > gain
I mean involving floats at all. If that's already the case, then I don't object to the patch (though it would be nice to know if it is in fact fixed point and parse it as such). -- Anton Khirnov _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
