avformat/matroskaenc: Don't waste bytes writing durations

Tags in the Matroska file format can be summarized as follows: There is
a level 1-element called Tags containing one or many Tag elements each
of which in turn contain a Targets element and one or many SimpleTags.
Each SimpleTag roughly corresponds to a single key-value pair similar to
an AVDictionaryEntry. The Targets meanwhile contains information to what
the metadata contained in the SimpleTags contained in the containing Tag
applies (i.e. to the file as a whole or to an individual track).

The Matroska muxer writes such metadata. It puts the metadata of every
stream into a Tag whose Targets makes it point to the corresponding
track. And if the output is seekable, then it also adds another Tag for
each track whose Targets corresponds to the track and where it reserves
space in a SimpleTag to write the duration at the end of the muxing
process into.

Yet there is no reason to write two Tag elements for a track and a few
bytes (typically 24 bytes per track) can be saved by adding the duration
SimpleTag to the other Tag of the same track (if it exists).

FATE has been updated because the output files changed. (Tests that
write to unseekable output (pipes) needn't be updated (no duration tag
has ever been written for them) and the same applies to tests without
further metadata.)

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
This commit is contained in:
Andreas Rheinhardt 2020-04-04 15:35:48 +02:00
parent 3c3ad1deb0
commit bd7dea3f4f
7 changed files with 53 additions and 59 deletions

View File

@ -1517,14 +1517,14 @@ static int mkv_check_tag_name(const char *name, uint32_t elementid)
}
static int mkv_write_tag(AVFormatContext *s, AVDictionary *m, uint32_t elementid,
uint64_t uid)
uint64_t uid, ebml_master *tag)
{
MatroskaMuxContext *mkv = s->priv_data;
ebml_master tag;
ebml_master tag2;
int ret;
AVDictionaryEntry *t = NULL;
ret = mkv_write_tag_targets(s, elementid, uid, &tag);
ret = mkv_write_tag_targets(s, elementid, uid, tag ? tag : &tag2);
if (ret < 0)
return ret;
@ -1536,7 +1536,9 @@ static int mkv_write_tag(AVFormatContext *s, AVDictionary *m, uint32_t elementid
}
}
end_ebml_master(mkv->tags_bc, tag);
if (!tag)
end_ebml_master(mkv->tags_bc, tag2);
return 0;
}
@ -1554,53 +1556,43 @@ static int mkv_check_tag(AVDictionary *m, uint32_t elementid)
static int mkv_write_tags(AVFormatContext *s)
{
MatroskaMuxContext *mkv = s->priv_data;
ebml_master tag, *tagp;
int i, ret;
ff_metadata_conv_ctx(s, ff_mkv_metadata_conv, NULL);
if (mkv_check_tag(s->metadata, 0)) {
ret = mkv_write_tag(s, s->metadata, 0, 0);
ret = mkv_write_tag(s, s->metadata, 0, 0, NULL);
if (ret < 0) return ret;
}
tagp = (s->pb->seekable & AVIO_SEEKABLE_NORMAL) && !mkv->is_live ? &tag : NULL;
for (i = 0; i < s->nb_streams; i++) {
AVStream *st = s->streams[i];
if (st->codecpar->codec_type == AVMEDIA_TYPE_ATTACHMENT)
continue;
if (!mkv_check_tag(st->metadata, MATROSKA_ID_TAGTARGETS_TRACKUID))
if (!tagp && !mkv_check_tag(st->metadata, MATROSKA_ID_TAGTARGETS_TRACKUID))
continue;
ret = mkv_write_tag(s, st->metadata, MATROSKA_ID_TAGTARGETS_TRACKUID, i + 1);
ret = mkv_write_tag(s, st->metadata, MATROSKA_ID_TAGTARGETS_TRACKUID,
i + 1, tagp);
if (ret < 0) return ret;
}
if ((s->pb->seekable & AVIO_SEEKABLE_NORMAL) && !mkv->is_live) {
for (i = 0; i < s->nb_streams; i++) {
AVIOContext *pb;
AVStream *st = s->streams[i];
ebml_master tag_target;
ebml_master tag;
if (tagp) {
AVIOContext *pb = mkv->tags_bc;
ebml_master simpletag;
if (st->codecpar->codec_type == AVMEDIA_TYPE_ATTACHMENT)
continue;
ret = mkv_write_tag_targets(s, MATROSKA_ID_TAGTARGETS_TRACKUID,
i + 1, &tag_target);
if (ret < 0)
return ret;
pb = mkv->tags_bc;
tag = start_ebml_master(pb, MATROSKA_ID_SIMPLETAG, 0);
simpletag = start_ebml_master(pb, MATROSKA_ID_SIMPLETAG, 0);
put_ebml_string(pb, MATROSKA_ID_TAGNAME, "DURATION");
mkv->tracks[i].duration_offset = avio_tell(pb);
// Reserve space to write duration as a 20-byte string.
// 2 (ebml id) + 1 (data size) + 20 (data)
put_ebml_void(pb, 23);
end_ebml_master(pb, simpletag);
end_ebml_master(pb, tag);
end_ebml_master(pb, tag_target);
}
}
@ -1612,7 +1604,8 @@ static int mkv_write_tags(AVFormatContext *s)
continue;
ret = mkv_write_tag(s, ch->metadata, MATROSKA_ID_TAGTARGETS_CHAPTERUID,
(uint32_t)ch->id + (uint64_t)mkv->chapter_id_offset);
(uint32_t)ch->id + (uint64_t)mkv->chapter_id_offset,
NULL);
if (ret < 0)
return ret;
}
@ -1626,7 +1619,8 @@ static int mkv_write_tags(AVFormatContext *s)
if (!mkv_check_tag(st->metadata, MATROSKA_ID_TAGTARGETS_ATTACHUID))
continue;
ret = mkv_write_tag(s, st->metadata, MATROSKA_ID_TAGTARGETS_ATTACHUID, attachment->fileuid);
ret = mkv_write_tag(s, st->metadata, MATROSKA_ID_TAGTARGETS_ATTACHUID,
attachment->fileuid, NULL);
if (ret < 0)
return ret;
}

View File

@ -1,5 +1,5 @@
2b363aecd6422c3ce9964983f5d0f3ef *tests/data/fate/matroska-flac-extradata-update.matroska
2049 tests/data/fate/matroska-flac-extradata-update.matroska
5070c157123b54e218c7e0a45d5606c8 *tests/data/fate/matroska-flac-extradata-update.matroska
1977 tests/data/fate/matroska-flac-extradata-update.matroska
#extradata 0: 34, 0x7acb09e7
#extradata 1: 34, 0x7acb09e7
#extradata 2: 34, 0x443402dd

View File

@ -1,5 +1,5 @@
92861b36a8220a3dae10d91cba614892 *tests/data/fate/rgb24-mkv.matroska
58216 tests/data/fate/rgb24-mkv.matroska
f9feab2a7ed8f1049df1b70982291505 *tests/data/fate/rgb24-mkv.matroska
58192 tests/data/fate/rgb24-mkv.matroska
#tb 0: 1/10
#media_type 0: video
#codec_id 0: rawvideo

View File

@ -1,3 +1,3 @@
58936d3ad4eb1372bd2e5845963fe17c *tests/data/lavf/lavf.mka
43563 tests/data/lavf/lavf.mka
9bd06ae5291de75c19a60c3f39db4c09 *tests/data/lavf/lavf.mka
43538 tests/data/lavf/lavf.mka
tests/data/lavf/lavf.mka CRC=0x3a1da17e

View File

@ -1,3 +1,3 @@
6ec6d6a058a85bf616e0b981bb8e383f *tests/data/lavf/lavf.mkv
320466 tests/data/lavf/lavf.mkv
85ef0666b3ad642221793b1c4f985011 *tests/data/lavf/lavf.mkv
320418 tests/data/lavf/lavf.mkv
tests/data/lavf/lavf.mkv CRC=0xec6c3c68

View File

@ -1,3 +1,3 @@
41b4f132ada6e0faedf92e909526a899 *tests/data/lavf/lavf.mkv_attachment
472617 tests/data/lavf/lavf.mkv_attachment
c339e42793d2a3cb1b8e99fc7a60de31 *tests/data/lavf/lavf.mkv_attachment
472569 tests/data/lavf/lavf.mkv_attachment
tests/data/lavf/lavf.mkv_attachment CRC=0xec6c3c68

View File

@ -1,48 +1,48 @@
ret: 0 st: 1 flags:1 dts: 0.000000 pts: 0.000000 pos: 714 size: 208
ret: 0 st: 1 flags:1 dts: 0.000000 pts: 0.000000 pos: 666 size: 208
ret: 0 st:-1 flags:0 ts:-1.000000
ret: 0 st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos: 930 size: 27837
ret: 0 st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos: 882 size: 27837
ret: 0 st:-1 flags:1 ts: 1.894167
ret: 0 st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292346 size: 27834
ret: 0 st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292298 size: 27834
ret: 0 st: 0 flags:0 ts: 0.788000
ret: 0 st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292346 size: 27834
ret: 0 st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292298 size: 27834
ret: 0 st: 0 flags:1 ts:-0.317000
ret: 0 st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos: 930 size: 27837
ret: 0 st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos: 882 size: 27837
ret:-1 st: 1 flags:0 ts: 2.577000
ret: 0 st: 1 flags:1 ts: 1.471000
ret: 0 st: 1 flags:1 dts: 0.993000 pts: 0.993000 pos: 320187 size: 209
ret: 0 st: 1 flags:1 dts: 0.993000 pts: 0.993000 pos: 320139 size: 209
ret: 0 st:-1 flags:0 ts: 0.365002
ret: 0 st: 0 flags:1 dts: 0.491000 pts: 0.491000 pos: 146898 size: 27925
ret: 0 st: 0 flags:1 dts: 0.491000 pts: 0.491000 pos: 146850 size: 27925
ret: 0 st:-1 flags:1 ts:-0.740831
ret: 0 st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos: 930 size: 27837
ret: 0 st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos: 882 size: 27837
ret:-1 st: 0 flags:0 ts: 2.153000
ret: 0 st: 0 flags:1 ts: 1.048000
ret: 0 st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292346 size: 27834
ret: 0 st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292298 size: 27834
ret: 0 st: 1 flags:0 ts:-0.058000
ret: 0 st: 1 flags:1 dts: 0.000000 pts: 0.000000 pos: 714 size: 208
ret: 0 st: 1 flags:1 dts: 0.000000 pts: 0.000000 pos: 666 size: 208
ret: 0 st: 1 flags:1 ts: 2.836000
ret: 0 st: 1 flags:1 dts: 0.993000 pts: 0.993000 pos: 320187 size: 209
ret: 0 st: 1 flags:1 dts: 0.993000 pts: 0.993000 pos: 320139 size: 209
ret:-1 st:-1 flags:0 ts: 1.730004
ret: 0 st:-1 flags:1 ts: 0.624171
ret: 0 st: 0 flags:1 dts: 0.491000 pts: 0.491000 pos: 146898 size: 27925
ret: 0 st: 0 flags:1 dts: 0.491000 pts: 0.491000 pos: 146850 size: 27925
ret: 0 st: 0 flags:0 ts:-0.482000
ret: 0 st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos: 930 size: 27837
ret: 0 st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos: 882 size: 27837
ret: 0 st: 0 flags:1 ts: 2.413000
ret: 0 st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292346 size: 27834
ret: 0 st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292298 size: 27834
ret:-1 st: 1 flags:0 ts: 1.307000
ret: 0 st: 1 flags:1 ts: 0.201000
ret: 0 st: 1 flags:1 dts: 0.000000 pts: 0.000000 pos: 714 size: 208
ret: 0 st: 1 flags:1 dts: 0.000000 pts: 0.000000 pos: 666 size: 208
ret: 0 st:-1 flags:0 ts:-0.904994
ret: 0 st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos: 930 size: 27837
ret: 0 st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos: 882 size: 27837
ret: 0 st:-1 flags:1 ts: 1.989173
ret: 0 st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292346 size: 27834
ret: 0 st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292298 size: 27834
ret: 0 st: 0 flags:0 ts: 0.883000
ret: 0 st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292346 size: 27834
ret: 0 st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292298 size: 27834
ret: 0 st: 0 flags:1 ts:-0.222000
ret: 0 st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos: 930 size: 27837
ret: 0 st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos: 882 size: 27837
ret:-1 st: 1 flags:0 ts: 2.672000
ret: 0 st: 1 flags:1 ts: 1.566000
ret: 0 st: 1 flags:1 dts: 0.993000 pts: 0.993000 pos: 320187 size: 209
ret: 0 st: 1 flags:1 dts: 0.993000 pts: 0.993000 pos: 320139 size: 209
ret: 0 st:-1 flags:0 ts: 0.460008
ret: 0 st: 0 flags:1 dts: 0.491000 pts: 0.491000 pos: 146898 size: 27925
ret: 0 st: 0 flags:1 dts: 0.491000 pts: 0.491000 pos: 146850 size: 27925
ret: 0 st:-1 flags:1 ts:-0.645825
ret: 0 st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos: 930 size: 27837
ret: 0 st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos: 882 size: 27837