return DECODE_SLICE_ERROR;
return DECODE_SLICE_MB_ADDR_ERROR;
static int mpeg_decode_slice(AVCodecContext *avctx,                               AVFrame *pict,                              int start_code,                              uint8_t *buf, int buf_size){    Mpeg1Context *s1 = avctx->priv_data;    MpegEncContext *s = &s1->mpeg_enc_ctx;    int ret;    const int field_pic= s->picture_structure != PICT_FRAME;    start_code = (start_code - 1) & 0xff;    if (start_code >= s->mb_height){        fprintf(stderr, "slice below image (%d >= %d)\n", start_code, s->mb_height);        return DECODE_SLICE_ERROR;    }        ff_mpeg1_clean_buffers(s);            /* start frame decoding */    if (s->first_slice) {      if(s->first_field || s->picture_structure==PICT_FRAME){        if(MPV_frame_start(s, avctx) < 0)            return DECODE_SLICE_FATAL_ERROR;        /* first check if we must repeat the frame */        s->current_picture.repeat_pict = 0;        if (s->repeat_first_field) {            if (s->progressive_sequence) {                if (s->top_field_first)                    s->current_picture.repeat_pict = 4;                else                    s->current_picture.repeat_pict = 2;            } else if (s->progressive_frame) {                s->current_picture.repeat_pict = 1;            }        }         //        printf("%d \n", s->current_picture.repeat_pict);        if(s->avctx->debug&FF_DEBUG_PICT_INFO){             printf("qp:%d fc:%2d%2d%2d%2d %s %s %s %s dc:%d pstruct:%d fdct:%d cmv:%d qtype:%d ivlc:%d rff:%d %s\n",                  s->qscale, s->mpeg_f_code[0][0],s->mpeg_f_code[0][1],s->mpeg_f_code[1][0],s->mpeg_f_code[1][1],                 s->pict_type == I_TYPE ? "I" : (s->pict_type == P_TYPE ? "P" : (s->pict_type == B_TYPE ? "B" : "S")),                  s->progressive_sequence ? "pro" :"", s->alternate_scan ? "alt" :"", s->top_field_first ? "top" :"",                  s->intra_dc_precision, s->picture_structure, s->frame_pred_frame_dct, s->concealment_motion_vectors,                 s->q_scale_type, s->intra_vlc_format, s->repeat_first_field, s->chroma_420_type ? "420" :"");        }      }else{ //second field            int i;            for(i=0; i<4; i++){                s->current_picture.data[i] = s->current_picture_ptr->data[i];                if(s->picture_structure == PICT_BOTTOM_FIELD){                    s->current_picture.data[i] += s->current_picture_ptr->linesize[i];                }             }      }    }    s->first_slice = 0;    init_get_bits(&s->gb, buf, buf_size*8);    s->qscale = get_qscale(s);    /* extra slice info */    while (get_bits1(&s->gb) != 0) {        skip_bits(&s->gb, 8);    }    s->mb_x=0;    for(;;) {        int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);        if (code < 0)            return -1; /* error = end of slice, but empty slice is bad or?*/        if (code >= 33) {            if (code == 33) {                s->mb_x += 33;            }            /* otherwise, stuffing, nothing to do */        } else {            s->mb_x += code;            break;        }    }        s->mb_y = start_code;    s->mb_skip_run= 0;    for(;;) {	s->dsp.clear_blocks(s->block[0]);                ret = mpeg_decode_mb(s, s->block);        dprintf("ret=%d\n", ret);        if (ret < 0)            return -1;                MPV_decode_mb(s, s->block);        if (++s->mb_x >= s->mb_width) {            if(s->picture_structure==PICT_FRAME){                ff_draw_horiz_band(s, 16*s->mb_y, 16);            }else{                if(!s->first_field){                    ff_draw_horiz_band(s, 32*s->mb_y, 32);                }            }            s->mb_x = 0;            s->mb_y++;            PRINT_QP("%s", "\n");        }        PRINT_QP("%2d", s->qscale);        /* skip mb handling */        if (s->mb_skip_run == -1) {            /* read again increment */            s->mb_skip_run = 0;            for(;;) {                int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);                if (code < 0)                    goto eos; /* error = end of slice */                if (code >= 33) {                    if (code == 33) {                        s->mb_skip_run += 33;                    }                    /* otherwise, stuffing, nothing to do */                } else {                    s->mb_skip_run += code;                    break;                }            }        }        if(s->mb_y<<field_pic >= s->mb_height){            fprintf(stderr, "slice too long\n");            return DECODE_SLICE_ERROR;        }    }eos: //end of slice        emms_c();//intf("%d %d %d %d\n", s->mb_y, s->mb_height, s->pict_type, s->picture_number);    /* end of slice reached */    if (s->mb_y<<field_pic == s->mb_height && !s->first_field) {        /* end of image */        if(s->mpeg2)            s->qscale >>=1;        MPV_frame_end(s);        if (s->pict_type == B_TYPE || s->low_delay) {            *pict= *(AVFrame*)&s->current_picture;        } else {            s->picture_number++;            /* latency of 1 frame for I and P frames */            /* XXX: use another variable than picture_number */            if (s->last_picture_ptr == NULL) {                return DECODE_SLICE_OK;            } else {                *pict= *(AVFrame*)&s->last_picture;            }        }        return DECODE_SLICE_EOP;    } else {        return DECODE_SLICE_OK;    }}