> On Apr 22, 2022, at 4:37 PM, Malviya, Janpriya <janpriya_malv...@bose.com> > wrote: > > Hello ffmpeg Dev team, > > While integrating FFmpeg for M4A , MP4 stream & facing issue that mov demuxer > trying to request seek for invalid seek offset. > > Issue details:- > - Modified doc/examples/demuxing_decoding.c example to support Custom > IO call-back because we have our own mechanism to read data from source > - In custom IO seek call back , we do not support “whence” values > AVSEEK_SIZE & SEEK_END , used to find stream size ( returning -1 in both the > cases ). > - In attached screen shot , where we are observing seek with invalid > seek offset and the seek requested after End of stream is detected > - Seek offset value 9223372036854775799 always the same ( I think > INT64_MAX – 8 , 8 is length Atom type & size field ) > - If we allow to return proper stream size in seek callback then this > problem is not observed.
The real issue isn’t about invalid seek offset, but use invalid box size/type due to EOF. Add another check just after the eof check in while condition isn’t efficient. I tried another method: [1/3] avformat/mov: remove an always true condition http://ffmpeg.org/pipermail/ffmpeg-devel/2022-April/295712.html [2/3] reindent [3/3] avformat/mov: fix use invalid box size/type due to eof http://ffmpeg.org/pipermail/ffmpeg-devel/2022-April/295713.html > > Fix : > In attached patch to verify EOS condition before going to parse atom data. > > Signed-off-by: Janpriya Malviya <janpriya_malv...@bose.com> > --- > libavformat/mov.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/libavformat/mov.c b/libavformat/mov.c > index 6c847de..9704550 100644 > --- a/libavformat/mov.c > +++ b/libavformat/mov.c > @@ -7556,6 +7556,10 @@ static int mov_read_default(MOVContext *c, AVIOContext > *pb, MOVAtom atom) > if (atom.size >= 8) { > a.size = avio_rb32(pb); > a.type = avio_rl32(pb); > + > + if(avio_feof(pb)) > + continue; > + > if (((a.type == MKTAG('f','r','e','e') && c->moov_retry) || > a.type == MKTAG('h','o','o','v')) && > a.size >= 8 && > -- > 2.7.4 > > <issueImage.png><reproduce_issue.c>_______________________________________________ > 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". > _______________________________________________ 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".
