MATROSKA_ID_DURATION  270 libavformat/matroskadec.c     { MATROSKA_ID_DURATION,           EBML_FLOAT, 0, offsetof(MatroskaDemuxContext,duration) },
MATROSKA_ID_DURATION  862 libavformat/matroskaenc.c         put_ebml_float(pb, MATROSKA_ID_DURATION, mkv->duration);