ffmpeg | branch: master | Tomas Härdin <g...@haerdin.se> | Mon Oct 14 16:45:35 2024 +0200| [baa23e40c190ad0afdc2398e60d4da2aacc86ad9] | committer: Tomas Härdin
lavf/mxfdec: Set a scan direction explicitly This prevents a theoretical case where seeks to a gap in an index can cause an infinite loop > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=baa23e40c190ad0afdc2398e60d4da2aacc86ad9 --- libavformat/mxfdec.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c index e5f59089ab..27e8e0c261 100644 --- a/libavformat/mxfdec.c +++ b/libavformat/mxfdec.c @@ -1907,7 +1907,7 @@ static int64_t mxf_essence_container_end(MXFContext *mxf, int body_sid) /* EditUnit -> absolute offset */ static int mxf_edit_unit_absolute_offset(MXFContext *mxf, MXFIndexTable *index_table, int64_t edit_unit, AVRational edit_rate, int64_t *edit_unit_out, int64_t *offset_out, MXFPartition **partition_out, int nag) { - int i = 0; + int i = 0, dir = 0; int64_t index_duration, index_end; MXFIndexTableSegment *first_segment, *last_segment; @@ -1939,7 +1939,7 @@ static int mxf_edit_unit_absolute_offset(MXFContext *mxf, MXFIndexTable *index_t i = FFMAX(0, FFMIN(index_table->nb_segments - 1, i64)); } - for (; i >= 0 && i < index_table->nb_segments;) { + for (; i >= 0 && i < index_table->nb_segments; i += dir) { MXFIndexTableSegment *s = index_table->segments[i]; if (s->index_start_position <= edit_unit && edit_unit < s->index_start_position + s->index_duration) { @@ -1969,12 +1969,14 @@ static int mxf_edit_unit_absolute_offset(MXFContext *mxf, MXFIndexTable *index_t *edit_unit_out = av_rescale_q(edit_unit, edit_rate, s->index_edit_rate); return mxf_absolute_bodysid_offset(mxf, index_table->body_sid, offset_temp, offset_out, partition_out); - } else if (edit_unit < s->index_start_position) { - // the segments are sorted by IndexStartPosition, so this is guaranteed to terminate - i--; - } else { - // edit_unit >= s->index_start_position + s->index_duration - i++; + } else if (dir == 0) { + // scan backwards if the segment is earlier than the current IndexStartPosition + // else scan forwards + if (edit_unit < s->index_start_position) { + dir = -1; + } else { + dir = 1; + } } } _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog To unsubscribe, visit link above, or email ffmpeg-cvslog-requ...@ffmpeg.org with subject "unsubscribe".
