[FFmpeg-cvslog] avformat/matroskadec: Make cluster parsing level compatible
Andreas Rheinhardt
git at videolan.org
Tue Jul 16 22:49:45 EEST 2019
ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at gmail.com> | Fri May 17 00:30:08 2019 +0200| [865c5370078fe743a8259a3f83d69e5a0cb693b2] | committer: James Almer
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 <andreas.rheinhardt at gmail.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=865c5370078fe743a8259a3f83d69e5a0cb693b2
---
libavformat/matroskadec.c | 106 ++++++++++++++++++++--------------------------
1 file changed, 47 insertions(+), 59 deletions(-)
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
@@ -815,24 +818,6 @@ static int matroska_resync(MatroskaDemuxContext *matroska, int64_t last_pos)
}
/*
- * 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
* number of 0-bits followed by a one. The position of the first
@@ -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;
}
More information about the ffmpeg-cvslog
mailing list