MATROSKA_ID_TRACKDEFAULTDURATION  431 libavformat/matroskadec.c     { MATROSKA_ID_TRACKDEFAULTDURATION,  EBML_UINT,  0, offsetof(MatroskaTrack, default_duration) },
MATROSKA_ID_TRACKDEFAULTDURATION  925 libavformat/matroskaenc.c             put_ebml_uint(pb, MATROSKA_ID_TRACKDEFAULTDURATION, 1E9 / av_q2d(st->avg_frame_rate));
MATROSKA_ID_TRACKDEFAULTDURATION  927 libavformat/matroskaenc.c             put_ebml_uint(pb, MATROSKA_ID_TRACKDEFAULTDURATION, av_q2d(codec->time_base)*1E9);