UINT8 *buf, int size)
UINT8 *buf, int size, int force_pts)
static int single_jpeg_write_packet(AVFormatContext *s, int stream_index,                            UINT8 *buf, int size){    put_buffer(&s->pb, buf, size);    put_flush_packet(&s->pb);    return 1; /* no more data can be sent */}