fsize = dv_assemble_frame((DVMuxContext *)s->priv_data, s->streams[stream_index], buf, size, &frame);
fsize = dv_assemble_frame((DVMuxContext *)s->priv_data, s->streams[pkt->stream_index], pkt->data, pkt->size, &frame);
static int dv_write_packet(struct AVFormatContext *s,                            int stream_index,                           const uint8_t *buf, int size, int64_t pts){    uint8_t* frame;    int fsize;       fsize = dv_assemble_frame((DVMuxContext *)s->priv_data, s->streams[stream_index],                              buf, size, &frame);    if (fsize > 0) {        put_buffer(&s->pb, frame, fsize);         put_flush_packet(&s->pb);    }     return 0;}