dprintf("pict_type=%d number=%d\n", s->pict_type, s->picture_number);
static int mpeg1_decode_picture(AVCodecContext *avctx,                                 uint8_t *buf, int buf_size){    Mpeg1Context *s1 = avctx->priv_data;    MpegEncContext *s = &s1->mpeg_enc_ctx;    int ref, f_code, vbv_delay;    init_get_bits(&s->gb, buf, buf_size*8);    ref = get_bits(&s->gb, 10); /* temporal ref */    s->pict_type = get_bits(&s->gb, 3);    dprintf("pict_type=%d number=%d\n", s->pict_type, s->picture_number);    vbv_delay= get_bits(&s->gb, 16);    if (s->pict_type == P_TYPE || s->pict_type == B_TYPE) {        s->full_pel[0] = get_bits1(&s->gb);        f_code = get_bits(&s->gb, 3);        if (f_code == 0)            return -1;        s->mpeg_f_code[0][0] = f_code;        s->mpeg_f_code[0][1] = f_code;    }    if (s->pict_type == B_TYPE) {        s->full_pel[1] = get_bits1(&s->gb);        f_code = get_bits(&s->gb, 3);        if (f_code == 0)            return -1;        s->mpeg_f_code[1][0] = f_code;        s->mpeg_f_code[1][1] = f_code;    }    s->current_picture.pict_type= s->pict_type;    s->current_picture.key_frame= s->pict_type == I_TYPE;        s->y_dc_scale = 8;    s->c_dc_scale = 8;    s->first_slice = 1;    return 0;}