diff options
| -rw-r--r-- | libavformat/matroskadec.c | 45 |
1 files changed, 21 insertions, 24 deletions
diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c index 0525a65dbd..400c7b7ed5 100644 --- a/libavformat/matroskadec.c +++ b/libavformat/matroskadec.c @@ -762,8 +762,6 @@ static int matroska_resync(MatroskaDemuxContext *matroska, int64_t last_pos) { AVIOContext *pb = matroska->ctx->pb; uint32_t id; - matroska->current_id = 0; - matroska->num_levels = 0; /* Try to seek to the last position to resync from. If this doesn't work, * we resync from the earliest position available: The start of the buffer. */ @@ -783,7 +781,13 @@ static int matroska_resync(MatroskaDemuxContext *matroska, int64_t last_pos) id == MATROSKA_ID_CUES || id == MATROSKA_ID_TAGS || id == MATROSKA_ID_SEEKHEAD || id == MATROSKA_ID_ATTACHMENTS || id == MATROSKA_ID_CLUSTER || id == MATROSKA_ID_CHAPTERS) { - matroska->current_id = id; + /* Prepare the context for parsing of a level 1 element. */ + matroska_reset_status(matroska, id, -1); + /* Given that we are here means that an error has occured, + * so treat the segment as unknown length in order not to + * discard valid data that happens to be beyond the designated + * end of the segment. */ + matroska->levels[0].length = EBML_UNKNOWN_LENGTH; return 0; } id = (id << 8) | avio_r8(pb); @@ -1679,18 +1683,11 @@ static int matroska_parse_seekhead_entry(MatroskaDemuxContext *matroska, matroska->current_id = 0; ret = ebml_parse(matroska, matroska_segment, matroska); - - /* remove dummy level */ - while (matroska->num_levels) { - uint64_t length = matroska->levels[--matroska->num_levels].length; - if (length == EBML_UNKNOWN_LENGTH) - break; - } } } - /* seek back */ - avio_seek(matroska->ctx->pb, before_pos, SEEK_SET); - matroska->current_id = saved_id; + /* Seek back - notice that in all instances where this is used it is safe + * to set the level to 1 and unset the position of the current cluster. */ + matroska_reset_status(matroska, saved_id, before_pos); return ret; } @@ -3604,9 +3601,7 @@ static int matroska_read_seek(AVFormatContext *s, int stream_index, timestamp = FFMAX(timestamp, st->index_entries[0].timestamp); if ((index = av_index_search_timestamp(st, timestamp, flags)) < 0 || index == st->nb_index_entries - 1) { - avio_seek(s->pb, st->index_entries[st->nb_index_entries - 1].pos, - SEEK_SET); - matroska->current_id = 0; + matroska_reset_status(matroska, 0, st->index_entries[st->nb_index_entries - 1].pos); while ((index = av_index_search_timestamp(st, timestamp, flags)) < 0 || index == st->nb_index_entries - 1) { matroska_clear_queue(matroska); if (matroska_parse_cluster(matroska) < 0) @@ -3626,8 +3621,8 @@ static int matroska_read_seek(AVFormatContext *s, int stream_index, tracks[i].end_timecode = 0; } - avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET); - matroska->current_id = 0; + /* We seek to a level 1 element, so set the appropriate status. */ + matroska_reset_status(matroska, 0, st->index_entries[index].pos); if (flags & AVSEEK_FLAG_ANY) { st->skip_to_keyframe = 0; matroska->skip_to_timecode = timestamp; @@ -3637,18 +3632,16 @@ static int matroska_read_seek(AVFormatContext *s, int stream_index, } matroska->skip_to_keyframe = 1; matroska->done = 0; - matroska->num_levels = 0; ff_update_cur_dts(s, st, st->index_entries[index].timestamp); return 0; err: // slightly hackish but allows proper fallback to // the generic seeking code. + matroska_reset_status(matroska, 0, -1); matroska_clear_queue(matroska); - matroska->current_id = 0; st->skip_to_keyframe = matroska->skip_to_keyframe = 0; matroska->done = 0; - matroska->num_levels = 0; return -1; } @@ -3711,6 +3704,7 @@ static CueDesc get_cue_desc(AVFormatContext *s, int64_t ts, int64_t cues_start) static int webm_clusters_start_with_keyframe(AVFormatContext *s) { MatroskaDemuxContext *matroska = s->priv_data; + uint32_t id = matroska->current_id; int64_t cluster_pos, before_pos; int index, rv = 1; if (s->streams[0]->nb_index_entries <= 0) return 0; @@ -3731,8 +3725,8 @@ static int webm_clusters_start_with_keyframe(AVFormatContext *s) read = ebml_read_length(matroska, matroska->ctx->pb, &cluster_length); if (read < 0) break; - avio_seek(s->pb, cluster_pos, SEEK_SET); - matroska->current_id = 0; + + matroska_reset_status(matroska, 0, cluster_pos); matroska_clear_queue(matroska); if (matroska_parse_cluster(matroska) < 0 || !matroska->queue) { @@ -3746,7 +3740,10 @@ static int webm_clusters_start_with_keyframe(AVFormatContext *s) break; } } - avio_seek(s->pb, before_pos, SEEK_SET); + + /* Restore the status after matroska_read_header: */ + matroska_reset_status(matroska, id, before_pos); + return rv; } |