When doing streamed output, with e.g. +dash, if the mfra box ended up being larger than the AVIOContext write buffer, the (unchecked) seeking back to update the box size would silently fail and produce an invalid mfra box.
This is similar to how other boxes are written in fragmented mode. Signed-off-by: Derek Buitenhuis <derek.buitenh...@gmail.com> --- It is still weird to me that we prefer all of our internal code to use ffio_free_dyn_buf but don't allow actual public API users to use this functionality. --- libavformat/movenc.c | 38 ++++++++++++++++++++++++++------------ 1 file changed, 26 insertions(+), 12 deletions(-) diff --git a/libavformat/movenc.c b/libavformat/movenc.c index b8e45760ee..7db2e28840 100644 --- a/libavformat/movenc.c +++ b/libavformat/movenc.c @@ -4798,28 +4798,40 @@ static int mov_write_tfra_tag(AVIOContext *pb, MOVTrack *track) static int mov_write_mfra_tag(AVIOContext *pb, MOVMuxContext *mov) { - int64_t pos = avio_tell(pb); - int i; + AVIOContext *mfra_pb; + int i, ret, sz; + uint8_t *buf; - avio_wb32(pb, 0); /* size placeholder */ - ffio_wfourcc(pb, "mfra"); + ret = avio_open_dyn_buf(&mfra_pb); + if (ret < 0) + return ret; + + avio_wb32(mfra_pb, 0); /* size placeholder */ + ffio_wfourcc(mfra_pb, "mfra"); /* An empty mfra atom is enough to indicate to the publishing point that * the stream has ended. */ if (mov->flags & FF_MOV_FLAG_ISML) - return update_size(pb, pos); + goto done_mfra; for (i = 0; i < mov->nb_streams; i++) { MOVTrack *track = &mov->tracks[i]; if (track->nb_frag_info) - mov_write_tfra_tag(pb, track); + mov_write_tfra_tag(mfra_pb, track); } - avio_wb32(pb, 16); - ffio_wfourcc(pb, "mfro"); - avio_wb32(pb, 0); /* version + flags */ - avio_wb32(pb, avio_tell(pb) + 4 - pos); + avio_wb32(mfra_pb, 16); + ffio_wfourcc(mfra_pb, "mfro"); + avio_wb32(mfra_pb, 0); /* version + flags */ + avio_wb32(mfra_pb, avio_tell(mfra_pb) + 4); - return update_size(pb, pos); +done_mfra: + + sz = update_size(mfra_pb, 0); + ret = avio_get_dyn_buf(mfra_pb, &buf); + avio_write(pb, buf, ret); + ffio_free_dyn_buf(&mfra_pb); + + return sz; } static int mov_write_mdat_tag(AVIOContext *pb, MOVMuxContext *mov) @@ -6987,7 +6999,9 @@ static int mov_write_trailer(AVFormatContext *s) } if (!(mov->flags & FF_MOV_FLAG_SKIP_TRAILER)) { avio_write_marker(s->pb, AV_NOPTS_VALUE, AVIO_DATA_MARKER_TRAILER); - mov_write_mfra_tag(pb, mov); + res = mov_write_mfra_tag(pb, mov); + if (res < 0) + return res; } } -- 2.27.0.rc2 _______________________________________________ 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".