On 5/16/2019 7:29 PM, Andreas Rheinhardt wrote: > By default, the data_offset member of the AVFormatInternal of the > AVFormatContext associated with the MatroskaDemuxContext has not been > initialized explicitly by any Matroska-specific function, so that it was > initialized by default to the offset at the end of matroska_read_header, > i.e. usually to the offset of the length field of the first encountered > cluster. This meant that in case that the Matroska-specific seek-code > fails because there are no index entries for the target track a seek to > data_offset would be performed and ordinary parsing would start from > there which is nonsense: The length field would be treated as EBML ID and > (if the length field is not longer than four bytes (EBML numbers that > long are rejected as invalid EBML IDs)) whatever comes next would be > treated as its EBML size although it simply isn't. > > Signed-off-by: Andreas Rheinhardt <andreas.rheinha...@gmail.com> > --- > libavformat/matroskadec.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c > index 927462d3ad..1cda5d5b76 100644 > --- a/libavformat/matroskadec.c > +++ b/libavformat/matroskadec.c > @@ -2669,6 +2669,9 @@ static int matroska_read_header(AVFormatContext *s) > pos = avio_tell(matroska->ctx->pb); > res = ebml_parse(matroska, matroska_segment, matroska); > } > + /* Set data_offset as it might be needed later by seek_frame_generic. */ > + if (matroska->current_id == MATROSKA_ID_CLUSTER) > + s->internal->data_offset = avio_tell(matroska->ctx->pb) - 4; > matroska_execute_seekhead(matroska); > > if (!matroska->time_scale)
Applied, thanks. _______________________________________________ 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".
