[FFmpeg-devel] [PATCH 2/6] avformat/matroskaenc: Unify writing level 1 elements preliminarily
Andreas Rheinhardt
andreas.rheinhardt at gmail.com
Thu Apr 30 01:21:52 EEST 2020
The Matroska muxer updates several header elements when the output is
seekable; if unseekable, the buffer containing the contents of the element
is immediately freed after writing. Before this commit, there were three
places doing exactly the same: Checking whether the output is seekable
and calling the function that writes and frees or the function that
just writes the EBML master. This has been unified; adding SeekHead
entries for these elements has been unified, too.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
---
There was unfortunately a naming collision: The MatroskaMuxContext
already contains an element tracks, so I settled for track for the
stored EBML master.
libavformat/matroskaenc.c | 135 +++++++++++++++++---------------------
1 file changed, 62 insertions(+), 73 deletions(-)
diff --git a/libavformat/matroskaenc.c b/libavformat/matroskaenc.c
index b50fd8dd9b..31f75abc64 100644
--- a/libavformat/matroskaenc.c
+++ b/libavformat/matroskaenc.c
@@ -69,6 +69,11 @@ typedef struct ebml_master {
int sizebytes; ///< how many bytes were reserved for the size
} ebml_master;
+typedef struct ebml_stored_master {
+ AVIOContext *bc;
+ int64_t pos;
+} ebml_stored_master;
+
typedef struct mkv_seekhead_entry {
uint32_t elementid;
uint64_t segmentpos;
@@ -115,12 +120,9 @@ typedef struct mkv_track {
typedef struct MatroskaMuxContext {
const AVClass *class;
int mode;
- AVIOContext *tags_bc;
- int64_t tags_pos;
- AVIOContext *info_bc;
- int64_t info_pos;
- AVIOContext *tracks_bc;
- int64_t tracks_pos;
+ ebml_stored_master info;
+ ebml_stored_master track;
+ ebml_stored_master tags;
ebml_master segment;
int64_t segment_offset;
AVIOContext *cluster_bc;
@@ -402,19 +404,25 @@ static void end_ebml_master_crc32(AVIOContext *pb, AVIOContext **dyn_cp,
}
/**
-* Complete ebml master without destroying the buffer, allowing for later updates
-*/
-static void end_ebml_master_crc32_preliminary(AVIOContext *pb, AVIOContext *dyn_cp,
- uint32_t id, int64_t *pos)
+ * Output EBML master. Keep the buffer if seekable, allowing for later updates.
+ * Furthermore always add a SeekHead Entry for this element.
+ */
+static void end_ebml_master_crc32_tentatively(AVIOContext *pb,
+ ebml_stored_master *elem,
+ MatroskaMuxContext *mkv, uint32_t id)
{
+ if ((pb->seekable & AVIO_SEEKABLE_NORMAL) && !mkv->is_live) {
uint8_t *buf;
- int size = avio_get_dyn_buf(dyn_cp, &buf);
+ int size = avio_get_dyn_buf(elem->bc, &buf);
- *pos = avio_tell(pb);
+ elem->pos = avio_tell(pb);
+ mkv_add_seekhead_entry(mkv, id, elem->pos);
put_ebml_id(pb, id);
put_ebml_length(pb, size, 0);
avio_write(pb, buf, size);
+ } else
+ end_ebml_master_crc32(pb, &elem->bc, mkv, id, 0, 0, 1);
}
static void put_xiph_size(AVIOContext *pb, int size)
@@ -433,9 +441,9 @@ static void mkv_deinit(AVFormatContext *s)
av_packet_unref(&mkv->cur_audio_pkt);
ffio_free_dyn_buf(&mkv->cluster_bc);
- ffio_free_dyn_buf(&mkv->info_bc);
- ffio_free_dyn_buf(&mkv->tracks_bc);
- ffio_free_dyn_buf(&mkv->tags_bc);
+ ffio_free_dyn_buf(&mkv->info.bc);
+ ffio_free_dyn_buf(&mkv->track.bc);
+ ffio_free_dyn_buf(&mkv->tags.bc);
av_freep(&mkv->cues.entries);
av_freep(&mkv->tracks);
@@ -1374,9 +1382,7 @@ static int mkv_write_tracks(AVFormatContext *s)
if (mkv->nb_attachments == s->nb_streams)
return 0;
- mkv_add_seekhead_entry(mkv, MATROSKA_ID_TRACKS, avio_tell(pb));
-
- ret = start_ebml_master_crc32(&mkv->tracks_bc, mkv);
+ ret = start_ebml_master_crc32(&mkv->track.bc, mkv);
if (ret < 0)
return ret;
@@ -1416,17 +1422,13 @@ static int mkv_write_tracks(AVFormatContext *s)
i == video_default_idx || i == audio_default_idx ||
i == subtitle_default_idx;
ret = mkv_write_track(s, mkv, st, &mkv->tracks[i],
- mkv->tracks_bc, is_default);
+ mkv->track.bc, is_default);
if (ret < 0)
return ret;
}
- if ((pb->seekable & AVIO_SEEKABLE_NORMAL) && !mkv->is_live)
- end_ebml_master_crc32_preliminary(pb, mkv->tracks_bc,
- MATROSKA_ID_TRACKS, &mkv->tracks_pos);
- else
- end_ebml_master_crc32(pb, &mkv->tracks_bc, mkv,
- MATROSKA_ID_TRACKS, 0, 0, 0);
+ end_ebml_master_crc32_tentatively(pb, &mkv->track, mkv,
+ MATROSKA_ID_TRACKS);
return 0;
}
@@ -1532,14 +1534,12 @@ static int mkv_write_tag_targets(AVFormatContext *s, uint32_t elementid,
ebml_master targets;
int ret;
- if (!mkv->tags_bc) {
- mkv_add_seekhead_entry(mkv, MATROSKA_ID_TAGS, avio_tell(s->pb));
-
- ret = start_ebml_master_crc32(&mkv->tags_bc, mkv);
+ if (!mkv->tags.bc) {
+ ret = start_ebml_master_crc32(&mkv->tags.bc, mkv);
if (ret < 0)
return ret;
}
- pb = mkv->tags_bc;
+ pb = mkv->tags.bc;
*tag = start_ebml_master(pb, MATROSKA_ID_TAG, 0);
targets = start_ebml_master(pb, MATROSKA_ID_TAGTARGETS, 4 + 1 + 8);
@@ -1577,14 +1577,14 @@ static int mkv_write_tag(AVFormatContext *s, const AVDictionary *m,
while ((t = av_dict_get(m, "", t, AV_DICT_IGNORE_SUFFIX))) {
if (mkv_check_tag_name(t->key, elementid)) {
- ret = mkv_write_simpletag(mkv->tags_bc, t);
+ ret = mkv_write_simpletag(mkv->tags.bc, t);
if (ret < 0)
return ret;
}
}
if (!tag)
- end_ebml_master(mkv->tags_bc, tag2);
+ end_ebml_master(mkv->tags.bc, tag2);
return 0;
}
@@ -1631,7 +1631,7 @@ static int mkv_write_tags(AVFormatContext *s)
return ret;
if (tagp) {
- AVIOContext *pb = mkv->tags_bc;
+ AVIOContext *pb = mkv->tags.bc;
ebml_master simpletag;
simpletag = start_ebml_master(pb, MATROSKA_ID_SIMPLETAG,
@@ -1680,13 +1680,9 @@ static int mkv_write_tags(AVFormatContext *s)
}
}
- if (mkv->tags_bc) {
- if ((s->pb->seekable & AVIO_SEEKABLE_NORMAL) && !mkv->is_live)
- end_ebml_master_crc32_preliminary(s->pb, mkv->tags_bc,
- MATROSKA_ID_TAGS, &mkv->tags_pos);
- else
- end_ebml_master_crc32(s->pb, &mkv->tags_bc, mkv,
- MATROSKA_ID_TAGS, 0, 0, 0);
+ if (mkv->tags.bc) {
+ end_ebml_master_crc32_tentatively(s->pb, &mkv->tags, mkv,
+ MATROSKA_ID_TAGS);
}
return 0;
}
@@ -1815,12 +1811,10 @@ static int mkv_write_header(AVFormatContext *s)
// one elements (except Clusters).
mkv_start_seekhead(mkv, pb);
- mkv_add_seekhead_entry(mkv, MATROSKA_ID_INFO, avio_tell(pb));
-
- ret = start_ebml_master_crc32(&mkv->info_bc, mkv);
+ ret = start_ebml_master_crc32(&mkv->info.bc, mkv);
if (ret < 0)
return ret;
- pb = mkv->info_bc;
+ pb = mkv->info.bc;
put_ebml_uint(pb, MATROSKA_ID_TIMECODESCALE, 1000000);
if ((tag = av_dict_get(s->metadata, "title", NULL, 0)))
@@ -1866,12 +1860,7 @@ static int mkv_write_header(AVFormatContext *s)
put_ebml_void(pb, 11); // assumes double-precision float to be written
}
}
- if ((s->pb->seekable & AVIO_SEEKABLE_NORMAL) && !mkv->is_live)
- end_ebml_master_crc32_preliminary(s->pb, mkv->info_bc,
- MATROSKA_ID_INFO, &mkv->info_pos);
- else
- end_ebml_master_crc32(s->pb, &mkv->info_bc, mkv,
- MATROSKA_ID_INFO, 0, 0, 0);
+ end_ebml_master_crc32_tentatively(s->pb, &mkv->info, mkv, MATROSKA_ID_INFO);
pb = s->pb;
ret = mkv_write_tracks(s);
@@ -2191,14 +2180,14 @@ static int mkv_check_new_extra_data(AVFormatContext *s, const AVPacket *pkt)
if (ret < 0)
return ret;
memcpy(par->extradata, side_data, side_data_size);
- avio_seek(mkv->tracks_bc, track->codecpriv_offset, SEEK_SET);
- mkv_write_codecprivate(s, mkv->tracks_bc, par, 1, 0);
- filler = MAX_PCE_SIZE + 2 + 4 - (avio_tell(mkv->tracks_bc) - track->codecpriv_offset);
+ avio_seek(mkv->track.bc, track->codecpriv_offset, SEEK_SET);
+ mkv_write_codecprivate(s, mkv->track.bc, par, 1, 0);
+ filler = MAX_PCE_SIZE + 2 + 4 - (avio_tell(mkv->track.bc) - track->codecpriv_offset);
if (filler)
- put_ebml_void(mkv->tracks_bc, filler);
- avio_seek(mkv->tracks_bc, track->sample_rate_offset, SEEK_SET);
- put_ebml_float(mkv->tracks_bc, MATROSKA_ID_AUDIOSAMPLINGFREQ, track->sample_rate);
- put_ebml_float(mkv->tracks_bc, MATROSKA_ID_AUDIOOUTSAMPLINGFREQ, output_sample_rate);
+ put_ebml_void(mkv->track.bc, filler);
+ avio_seek(mkv->track.bc, track->sample_rate_offset, SEEK_SET);
+ put_ebml_float(mkv->track.bc, MATROSKA_ID_AUDIOSAMPLINGFREQ, track->sample_rate);
+ put_ebml_float(mkv->track.bc, MATROSKA_ID_AUDIOOUTSAMPLINGFREQ, output_sample_rate);
} else if (!par->extradata_size && !track->sample_rate) {
// No extradata (codecpar or packet side data).
av_log(s, AV_LOG_ERROR, "Error parsing AAC extradata, unable to determine samplerate.\n");
@@ -2214,8 +2203,8 @@ static int mkv_check_new_extra_data(AVFormatContext *s, const AVPacket *pkt)
return AVERROR(EINVAL);
}
par->extradata = side_data;
- avio_seek(mkv->tracks_bc, track->codecpriv_offset, SEEK_SET);
- mkv_write_codecprivate(s, mkv->tracks_bc, par, 1, 0);
+ avio_seek(mkv->track.bc, track->codecpriv_offset, SEEK_SET);
+ mkv_write_codecprivate(s, mkv->track.bc, par, 1, 0);
par->extradata = old_extradata;
}
break;
@@ -2236,9 +2225,9 @@ static int mkv_check_new_extra_data(AVFormatContext *s, const AVPacket *pkt)
av_free(codecpriv);
return AVERROR_INVALIDDATA;
}
- avio_seek(mkv->tracks_bc, track->codecpriv_offset, SEEK_SET);
+ avio_seek(mkv->track.bc, track->codecpriv_offset, SEEK_SET);
// Do not write the OBUs as we don't have space saved for them
- put_ebml_binary(mkv->tracks_bc, MATROSKA_ID_CODECPRIVATE, codecpriv, 4);
+ put_ebml_binary(mkv->track.bc, MATROSKA_ID_CODECPRIVATE, codecpriv, 4);
av_free(codecpriv);
ret = ff_alloc_extradata(par, side_data_size);
if (ret < 0)
@@ -2518,25 +2507,25 @@ static int mkv_write_trailer(AVFormatContext *s)
}
after_cues:
- ret = mkv_write_seekhead(pb, mkv, 1, mkv->info_pos);
+ ret = mkv_write_seekhead(pb, mkv, 1, mkv->info.pos);
if (ret < 0)
return ret;
// update the duration
av_log(s, AV_LOG_DEBUG, "end duration = %" PRIu64 "\n", mkv->duration);
- avio_seek(mkv->info_bc, mkv->duration_offset, SEEK_SET);
- put_ebml_float(mkv->info_bc, MATROSKA_ID_DURATION, mkv->duration);
- end_ebml_master_crc32(pb, &mkv->info_bc, mkv, MATROSKA_ID_INFO, 0, 0, 0);
+ avio_seek(mkv->info.bc, mkv->duration_offset, SEEK_SET);
+ put_ebml_float(mkv->info.bc, MATROSKA_ID_DURATION, mkv->duration);
+ end_ebml_master_crc32(pb, &mkv->info.bc, mkv, MATROSKA_ID_INFO, 0, 0, 0);
- if (mkv->tracks_bc) {
+ if (mkv->track.bc) {
// write Tracks master
- avio_seek(pb, mkv->tracks_pos, SEEK_SET);
- end_ebml_master_crc32(pb, &mkv->tracks_bc, mkv,
+ avio_seek(pb, mkv->track.pos, SEEK_SET);
+ end_ebml_master_crc32(pb, &mkv->track.bc, mkv,
MATROSKA_ID_TRACKS, 0, 0, 0);
}
// update stream durations
- if (mkv->tags_bc) {
+ if (mkv->tags.bc) {
int i;
for (i = 0; i < s->nb_streams; ++i) {
const AVStream *st = s->streams[i];
@@ -2549,18 +2538,18 @@ static int mkv_write_trailer(AVFormatContext *s)
av_log(s, AV_LOG_DEBUG, "stream %d end duration = %" PRIu64 "\n", i,
track->duration);
- avio_seek(mkv->tags_bc, track->duration_offset, SEEK_SET);
+ avio_seek(mkv->tags.bc, track->duration_offset, SEEK_SET);
snprintf(duration_string, 20, "%02d:%02d:%012.9f",
(int) duration_sec / 3600, ((int) duration_sec / 60) % 60,
fmod(duration_sec, 60));
- put_ebml_binary(mkv->tags_bc, MATROSKA_ID_TAGSTRING, duration_string, 20);
+ put_ebml_binary(mkv->tags.bc, MATROSKA_ID_TAGSTRING, duration_string, 20);
}
}
- avio_seek(pb, mkv->tags_pos, SEEK_SET);
- end_ebml_master_crc32(pb, &mkv->tags_bc, mkv,
+ avio_seek(pb, mkv->tags.pos, SEEK_SET);
+ end_ebml_master_crc32(pb, &mkv->tags.bc, mkv,
MATROSKA_ID_TAGS, 0, 0, 0);
}
--
2.20.1
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