+ track = start_ebml_master(pb, MATROSKA_ID_TRACKENTRY, 0);
+ put_ebml_uint (pb, MATROSKA_ID_TRACKNUMBER , i + 1);
+ put_ebml_uint (pb, MATROSKA_ID_TRACKUID , i + 1);
+ put_ebml_uint (pb, MATROSKA_ID_TRACKFLAGLACING , 0); // no lacing (yet)
+
+ if ((tag = av_dict_get(st->metadata, "title", NULL, 0)))
+ put_ebml_string(pb, MATROSKA_ID_TRACKNAME, tag->value);
+ tag = av_dict_get(st->metadata, "language", NULL, 0);
+ put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, tag ? tag->value:"und");
+
+ // The default value for TRACKFLAGDEFAULT is 1, so add element
+ // if we need to clear it.
+ if (!(st->disposition & AV_DISPOSITION_DEFAULT))
+ put_ebml_uint(pb, MATROSKA_ID_TRACKFLAGDEFAULT, !!(st->disposition & AV_DISPOSITION_DEFAULT));
+ if (st->disposition & AV_DISPOSITION_FORCED)
+ put_ebml_uint(pb, MATROSKA_ID_TRACKFLAGFORCED, !!(st->disposition & AV_DISPOSITION_FORCED));
+
+ if (par->codec_type == AVMEDIA_TYPE_AUDIO && par->initial_padding) {
+ mkv->tracks[i].ts_offset = av_rescale_q(par->initial_padding,
+ (AVRational){ 1, par->sample_rate },
+ st->time_base);
+
+ put_ebml_uint(pb, MATROSKA_ID_CODECDELAY,
+ av_rescale_q(par->initial_padding,
+ (AVRational){ 1, par->sample_rate },
+ (AVRational){ 1, 1000000000 }));
+ }
+
+ // look for a codec ID string specific to mkv to use,
+ // if none are found, use AVI codes
+ for (j = 0; ff_mkv_codec_tags[j].id != AV_CODEC_ID_NONE; j++) {
+ if (ff_mkv_codec_tags[j].id == par->codec_id) {
+ put_ebml_string(pb, MATROSKA_ID_CODECID, ff_mkv_codec_tags[j].str);
+ native_id = 1;
+ break;
+ }
+ }
+
+ if (mkv->mode == MODE_WEBM && !(par->codec_id == AV_CODEC_ID_VP8 ||
+ par->codec_id == AV_CODEC_ID_VP9 ||
+ par->codec_id == AV_CODEC_ID_OPUS ||
+ par->codec_id == AV_CODEC_ID_VORBIS)) {
+ av_log(s, AV_LOG_ERROR,
+ "Only VP8 or VP9 video and Vorbis or Opus audio are supported for WebM.\n");
+ return AVERROR(EINVAL);
+ }
+
+ switch (par->codec_type) {
+ case AVMEDIA_TYPE_VIDEO:
+ mkv->have_video = 1;
+ put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_VIDEO);
+ if (st->avg_frame_rate.num > 0 && st->avg_frame_rate.den > 0)
+ put_ebml_uint(pb, MATROSKA_ID_TRACKDEFAULTDURATION, 1E9 / av_q2d(st->avg_frame_rate));
+
+ if (!native_id &&
+ ff_codec_get_tag(ff_codec_movvideo_tags, par->codec_id) &&
+ (!ff_codec_get_tag(ff_codec_bmp_tags, par->codec_id) ||
+ par->codec_id == AV_CODEC_ID_SVQ1 ||
+ par->codec_id == AV_CODEC_ID_SVQ3 ||
+ par->codec_id == AV_CODEC_ID_CINEPAK))
+ qt_id = 1;
+
+ if (qt_id)
+ put_ebml_string(pb, MATROSKA_ID_CODECID, "V_QUICKTIME");
+ else if (!native_id) {
+ // if there is no mkv-specific codec ID, use VFW mode
+ put_ebml_string(pb, MATROSKA_ID_CODECID, "V_MS/VFW/FOURCC");
+ mkv->tracks[i].write_dts = 1;
+ }
+
+ subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKVIDEO, 0);
+
+ put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELWIDTH , par->width);
+ put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELHEIGHT, par->height);
+
+ mkv_write_field_order(pb, par->field_order);
+
+ // check both side data and metadata for stereo information,
+ // write the result to the bitstream if any is found
+ ret = mkv_write_stereo_mode(s, pb, st, mkv->mode);
+ if (ret < 0)
+ return ret;
+ ret = mkv_write_video_projection(s, pb, st);
+ if (ret < 0)
+ return ret;
+
+ end_ebml_master(pb, subinfo);
+ break;
+
+ case AVMEDIA_TYPE_AUDIO:
+ put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_AUDIO);
+
+ if (!native_id)
+ // no mkv-specific ID, use ACM mode
+ put_ebml_string(pb, MATROSKA_ID_CODECID, "A_MS/ACM");
+
+ subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKAUDIO, 0);
+ put_ebml_uint (pb, MATROSKA_ID_AUDIOCHANNELS , par->channels);
+
+ mkv->tracks[i].sample_rate_offset = avio_tell(pb);
+ put_ebml_float (pb, MATROSKA_ID_AUDIOSAMPLINGFREQ, sample_rate);
+ if (output_sample_rate)
+ put_ebml_float(pb, MATROSKA_ID_AUDIOOUTSAMPLINGFREQ, output_sample_rate);
+ if (bit_depth)
+ put_ebml_uint(pb, MATROSKA_ID_AUDIOBITDEPTH, bit_depth);
+ end_ebml_master(pb, subinfo);
+ break;
+
+ case AVMEDIA_TYPE_SUBTITLE:
+ put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_SUBTITLE);
+ if (!native_id) {
+ av_log(s, AV_LOG_ERROR, "Subtitle codec %d is not supported.\n", par->codec_id);
+ return AVERROR(ENOSYS);
+ }
+ break;
+ default:
+ av_log(s, AV_LOG_ERROR, "Only audio, video, and subtitles are supported for Matroska.\n");
+ break;
+ }
+
+ mkv->tracks[i].codecpriv_offset = avio_tell(pb);
+ ret = mkv_write_codecprivate(s, pb, par, native_id, qt_id);
+ if (ret < 0)
+ return ret;
+
+ end_ebml_master(pb, track);
+
+ return 0;
+}
+
+static int mkv_write_tracks(AVFormatContext *s)
+{
+ MatroskaMuxContext *mkv = s->priv_data;
+ AVIOContext *pb = s->pb;
+ ebml_master tracks;
+ int i, ret;
+
+ ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_TRACKS, avio_tell(pb));
+ if (ret < 0)
+ return ret;
+
+ tracks = start_ebml_master(pb, MATROSKA_ID_TRACKS, 0);
+ for (i = 0; i < s->nb_streams; i++) {
+ ret = mkv_write_track(s, mkv, i, pb);
+ if (ret < 0)
+ return ret;