avformat/cafdec: Do not build an index if all packets are the same

Fixes: Timeout
Fixes: 28214/clusterfuzz-testcase-minimized-ffmpeg_dem_CAF_fuzzer-6495999421579264

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit ea12590c8ecc1e3c4c7732e5adced21fb5feffa6)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2021-03-04 19:21:35 +01:00
parent 419f62c902
commit ee059d8ef8

View File

@ -204,15 +204,20 @@ static int read_pakt_chunk(AVFormatContext *s, int64_t size)
st->nb_frames += avio_rb32(pb); /* priming frames */
st->nb_frames += avio_rb32(pb); /* remainder frames */
st->duration = 0;
for (i = 0; i < num_packets; i++) {
if (avio_feof(pb))
return AVERROR_INVALIDDATA;
ret = av_add_index_entry(s->streams[0], pos, st->duration, 0, 0, AVINDEX_KEYFRAME);
if (ret < 0)
return ret;
pos += caf->bytes_per_packet ? caf->bytes_per_packet : ff_mp4_read_descr_len(pb);
st->duration += caf->frames_per_packet ? caf->frames_per_packet : ff_mp4_read_descr_len(pb);
if (caf->bytes_per_packet > 0 && caf->frames_per_packet > 0) {
st->duration = caf->frames_per_packet * num_packets;
pos = caf-> bytes_per_packet * num_packets;
} else {
st->duration = 0;
for (i = 0; i < num_packets; i++) {
if (avio_feof(pb))
return AVERROR_INVALIDDATA;
ret = av_add_index_entry(s->streams[0], pos, st->duration, 0, 0, AVINDEX_KEYFRAME);
if (ret < 0)
return ret;
pos += caf->bytes_per_packet ? caf->bytes_per_packet : ff_mp4_read_descr_len(pb);
st->duration += caf->frames_per_packet ? caf->frames_per_packet : ff_mp4_read_descr_len(pb);
}
}
if (avio_tell(pb) - ccount > size) {