From 865c5370078fe743a8259a3f83d69e5a0cb693b2 Mon Sep 17 00:00:00 2001 From: Andreas Rheinhardt Date: Fri, 17 May 2019 00:30:08 +0200 Subject: avformat/matroskadec: Make cluster parsing level compatible Before this commit, the parsing of clusters mixed EBML levels by allowing elements from different levels in a EbmlSyntax (namely matroska_cluster_parsing). This has been changed. And the level is now explicitly used to determine how to parse. Signed-off-by: Andreas Rheinhardt --- libavformat/matroskadec.c | 106 ++++++++++++++++++++-------------------------- 1 file changed, 47 insertions(+), 59 deletions(-) (limited to 'libavformat/matroskadec.c') diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c index 05c12edd16..db1b4b864f 100644 --- a/libavformat/matroskadec.c +++ b/libavformat/matroskadec.c @@ -722,15 +722,10 @@ static const EbmlSyntax matroska_cluster_parsing[] = { { MATROSKA_ID_SIMPLEBLOCK, EBML_BIN, 0, offsetof(MatroskaBlock, bin) }, { MATROSKA_ID_CLUSTERPOSITION, EBML_NONE }, { MATROSKA_ID_CLUSTERPREVSIZE, EBML_NONE }, - { MATROSKA_ID_INFO, EBML_NONE }, - { MATROSKA_ID_CUES, EBML_NONE }, - { MATROSKA_ID_TAGS, EBML_NONE }, - { MATROSKA_ID_SEEKHEAD, EBML_NONE }, - { MATROSKA_ID_CLUSTER, EBML_STOP }, - { 0 } /* We don't want to go back to level 0, so don't add the parent. */ + CHILD_OF(matroska_segment) }; -static const EbmlSyntax matroska_cluster[] = { +static const EbmlSyntax matroska_cluster_initial[] = { { MATROSKA_ID_CLUSTERTIMECODE, EBML_UINT, 0, offsetof(MatroskaCluster, timecode) }, { MATROSKA_ID_BLOCKGROUP, EBML_STOP }, { MATROSKA_ID_SIMPLEBLOCK, EBML_STOP }, @@ -739,12 +734,20 @@ static const EbmlSyntax matroska_cluster[] = { CHILD_OF(matroska_segment) }; +static const EbmlSyntax matroska_cluster_enter[] = { + { MATROSKA_ID_CLUSTER, EBML_NEST, 0, 0, { .n = matroska_cluster_initial } }, + { 0 } +}; + static const EbmlSyntax matroska_clusters[] = { - { MATROSKA_ID_CLUSTER, EBML_NEST, 0, 0, { .n = matroska_cluster } }, - { MATROSKA_ID_INFO, EBML_NONE }, - { MATROSKA_ID_CUES, EBML_NONE }, - { MATROSKA_ID_TAGS, EBML_NONE }, - { MATROSKA_ID_SEEKHEAD, EBML_NONE }, + { MATROSKA_ID_CLUSTER, EBML_STOP }, + { MATROSKA_ID_CUES, EBML_NONE }, + { MATROSKA_ID_TAGS, EBML_NONE }, + { MATROSKA_ID_INFO, EBML_NONE }, + { MATROSKA_ID_TRACKS, EBML_NONE }, + { MATROSKA_ID_ATTACHMENTS, EBML_NONE }, + { MATROSKA_ID_CHAPTERS, EBML_NONE }, + { MATROSKA_ID_SEEKHEAD, EBML_NONE }, { 0 } /* We don't want to go back to level 0, so don't add the parent. */ }; #undef CHILD_OF @@ -814,24 +817,6 @@ static int matroska_resync(MatroskaDemuxContext *matroska, int64_t last_pos) return pb->error ? pb->error : AVERROR_EOF; } -/* - * Return: Whether we reached the end of a level in the hierarchy or not. - */ -static int ebml_level_end(MatroskaDemuxContext *matroska) -{ - AVIOContext *pb = matroska->ctx->pb; - int64_t pos = avio_tell(pb); - - if (matroska->num_levels > 0) { - MatroskaLevel *level = &matroska->levels[matroska->num_levels - 1]; - if (pos - level->start >= level->length || matroska->current_id) { - matroska->num_levels--; - return 1; - } - } - return (matroska->is_live && matroska->ctx->pb->eof_reached) ? 1 : 0; -} - /* * Read: an "EBML number", which is defined as a variable-length * array of bytes. The first byte indicates the length by giving a @@ -3604,43 +3589,39 @@ static int matroska_parse_cluster(MatroskaDemuxContext *matroska) MatroskaCluster *cluster = &matroska->current_cluster; MatroskaBlock *block = &cluster->block; int res; - res = ebml_parse(matroska, - matroska_cluster_parsing, - cluster); - if (res == 1) { - /* New Cluster */ - if (cluster->pos) - ebml_level_end(matroska); - cluster->pos = avio_tell(matroska->ctx->pb); - /* sizeof the ID which was already read */ - if (matroska->current_id) - cluster->pos -= 4; - res = ebml_parse(matroska, - matroska_clusters, - cluster); - /* Try parsing the block again. */ - if (res == 1) - res = ebml_parse(matroska, - matroska_cluster_parsing, - cluster); - else - cluster->pos = 0; + + av_assert0(matroska->num_levels <= 2); + + if (matroska->num_levels == 1) { + res = ebml_parse(matroska, matroska_clusters, NULL); + + if (res == 1) { + /* Found a cluster: subtract the size of the ID already read. */ + cluster->pos = avio_tell(matroska->ctx->pb) - 4; + + res = ebml_parse(matroska, matroska_cluster_enter, cluster); + if (res < 0) + return res; + } } - if (res >= 0 && block->bin.size > 0) { + if (matroska->num_levels == 2) { + int err = 0; + /* We are inside a cluster. */ + res = ebml_parse(matroska, matroska_cluster_parsing, cluster); + + if (res >= 0 && block->bin.size > 0) { int is_keyframe = block->non_simple ? block->reference == INT64_MIN : -1; uint8_t* additional = block->additional.size > 0 ? block->additional.data : NULL; - res = matroska_parse_block(matroska, block->bin.buf, block->bin.data, + err = matroska_parse_block(matroska, block->bin.buf, block->bin.data, block->bin.size, block->bin.pos, - matroska->current_cluster.timecode, - block->duration, is_keyframe, - additional, block->additional_id, - block->additional.size, - cluster->pos, + cluster->timecode, block->duration, + is_keyframe, additional, block->additional_id, + block->additional.size, cluster->pos, block->discard_padding); - } + } if (res == LEVEL_ENDED) cluster->pos = 0; @@ -3648,6 +3629,13 @@ static int matroska_parse_cluster(MatroskaDemuxContext *matroska) ebml_free(matroska_blockgroup, block); memset(block, 0, sizeof(*block)); + if (err < 0) + return err; + } else if (!matroska->num_levels) { + matroska->done = 1; + return AVERROR_EOF; + } + return res; } -- cgit v1.2.3