put_be32(pb, track->cluster[cl][id].chunkSize);
put_be32(pb, track->cluster[cl][id].samplesInChunk);
static int mov_write_stsc_tag(ByteIOContext *pb, MOVTrack* track){    int index = 0, oldval = -1, i, entryPos, curpos;    int pos = url_ftell(pb);    put_be32(pb, 0); /* size */    put_tag(pb, "stsc");    put_be32(pb, 0); // version & flags     entryPos = url_ftell(pb);    put_be32(pb, track->entry); // entry count     for (i=0; i<track->entry; i++) {        int cl = i / MOV_INDEX_CLUSTER_SIZE;        int id = i % MOV_INDEX_CLUSTER_SIZE;        if(oldval != track->cluster[cl][id].chunkSize)         {            put_be32(pb, i+1); // first chunk             put_be32(pb, track->cluster[cl][id].chunkSize);            put_be32(pb, 0x1); // sample description index             oldval = track->cluster[cl][id].chunkSize;            index++;        }    }    curpos = url_ftell(pb);    url_fseek(pb, entryPos, SEEK_SET);    put_be32(pb, index); // rewrite size     url_fseek(pb, curpos, SEEK_SET);    return updateSize (pb, pos);}