MATROSKA_ID_DURATION  340 libavformat/matroskadec.c     { MATROSKA_ID_DURATION,      EBML_FLOAT, 0, offsetof(MatroskaDemuxContext, duration) },
MATROSKA_ID_DURATION 1943 libavformat/matroskaenc.c         put_ebml_float(pb, MATROSKA_ID_DURATION, mkv->duration);