put_be32(pb, track->frameCount);  put_be32(pb, track->sampleDelta);
put_be32(pb, track->sampleCount);  put_be32(pb, track->sampleDuration);
static int mov_write_stts_tag(ByteIOContext *pb, MOVTrack* track){    put_be32(pb, 0x18); /* size */    put_tag(pb, "stts");    put_be32(pb, 0); /* version & flags */    put_be32(pb, 1); /* entry count */    put_be32(pb, track->frameCount); /* sample count */    put_be32(pb, track->sampleDelta); /* sample delta */    return 0x18;}