int ff_h264_decode_mb_cavlc(H264Context *h){

    MpegEncContext * const s = &h->s;

    int mb_xy;

    int partition_count;

    unsigned int mb_type, cbp;

    int dct8x8_allowed= h->pps.transform_8x8_mode;



    mb_xy = h->mb_xy = s->mb_x + s->mb_y*s->mb_stride;



    tprintf(s->avctx, "pic:%d mb:%d/%d\n", h->frame_num, s->mb_x, s->mb_y);

    cbp = 0; 



    if(h->slice_type_nos != FF_I_TYPE){

        if(s->mb_skip_run==-1)

            s->mb_skip_run= get_ue_golomb(&s->gb);



        if (s->mb_skip_run--) {

            if(FRAME_MBAFF && (s->mb_y&1) == 0){

                if(s->mb_skip_run==0)

                    h->mb_mbaff = h->mb_field_decoding_flag = get_bits1(&s->gb);

                else

                    predict_field_decoding_flag(h);

            }

            decode_mb_skip(h);

            return 0;

        }

    }

    if(FRAME_MBAFF){

        if( (s->mb_y&1) == 0 )

            h->mb_mbaff = h->mb_field_decoding_flag = get_bits1(&s->gb);

    }



    h->prev_mb_skipped= 0;



    mb_type= get_ue_golomb(&s->gb);

    if(h->slice_type_nos == FF_B_TYPE){

        if(mb_type < 23){

            partition_count= b_mb_type_info[mb_type].partition_count;

            mb_type=         b_mb_type_info[mb_type].type;

        }else{

            mb_type -= 23;

            goto decode_intra_mb;

        }

    }else if(h->slice_type_nos == FF_P_TYPE){

        if(mb_type < 5){

            partition_count= p_mb_type_info[mb_type].partition_count;

            mb_type=         p_mb_type_info[mb_type].type;

        }else{

            mb_type -= 5;

            goto decode_intra_mb;

        }

    }else{

       assert(h->slice_type_nos == FF_I_TYPE);

        if(h->slice_type == FF_SI_TYPE && mb_type)

            mb_type--;

decode_intra_mb:

        if(mb_type > 25){

            av_log(h->s.avctx, AV_LOG_ERROR, "mb_type %d in %c slice too large at %d %d\n", mb_type, av_get_pict_type_char(h->slice_type), s->mb_x, s->mb_y);

            return -1;

        }

        partition_count=0;

        cbp= i_mb_type_info[mb_type].cbp;

        h->intra16x16_pred_mode= i_mb_type_info[mb_type].pred_mode;

        mb_type= i_mb_type_info[mb_type].type;

    }



    if(MB_FIELD)

        mb_type |= MB_TYPE_INTERLACED;



    h->slice_table[ mb_xy ]= h->slice_num;



    if(IS_INTRA_PCM(mb_type)){

        unsigned int x;



        

        align_get_bits(&s->gb);



        

        for(x=0; x < (CHROMA ? 384 : 256); x++){

            ((uint8_t*)h->mb)[x]= get_bits(&s->gb, 8);

        }



        

        s->current_picture.qscale_table[mb_xy]= 0;

        

        memset(h->non_zero_count[mb_xy], 16, 16);



        s->current_picture.mb_type[mb_xy]= mb_type;

        return 0;

    }



    if(MB_MBAFF){

        h->ref_count[0] <<= 1;

        h->ref_count[1] <<= 1;

    }



    fill_caches(h, mb_type, 0);



    

    if(IS_INTRA(mb_type)){

        int pred_mode;



        if(IS_INTRA4x4(mb_type)){

            int i;

            int di = 1;

            if(dct8x8_allowed && get_bits1(&s->gb)){

                mb_type |= MB_TYPE_8x8DCT;

                di = 4;

            }





            for(i=0; i<16; i+=di){

                int mode= pred_intra_mode(h, i);



                if(!get_bits1(&s->gb)){

                    const int rem_mode= get_bits(&s->gb, 3);

                    mode = rem_mode + (rem_mode >= mode);

                }



                if(di==4)

                    fill_rectangle( &h->intra4x4_pred_mode_cache[ scan8[i] ], 2, 2, 8, mode, 1 );

                else

                    h->intra4x4_pred_mode_cache[ scan8[i] ] = mode;

            }

            ff_h264_write_back_intra_pred_mode(h);

            if( ff_h264_check_intra4x4_pred_mode(h) < 0)

                return -1;

        }else{

            h->intra16x16_pred_mode= ff_h264_check_intra_pred_mode(h, h->intra16x16_pred_mode);

            if(h->intra16x16_pred_mode < 0)

                return -1;

        }

        if(CHROMA){

            pred_mode= ff_h264_check_intra_pred_mode(h, get_ue_golomb_31(&s->gb));

            if(pred_mode < 0)

                return -1;

            h->chroma_pred_mode= pred_mode;

        }

    }else if(partition_count==4){

        int i, j, sub_partition_count[4], list, ref[2][4];



        if(h->slice_type_nos == FF_B_TYPE){

            for(i=0; i<4; i++){

                h->sub_mb_type[i]= get_ue_golomb_31(&s->gb);

                if(h->sub_mb_type[i] >=13){

                    av_log(h->s.avctx, AV_LOG_ERROR, "B sub_mb_type %u out of range at %d %d\n", h->sub_mb_type[i], s->mb_x, s->mb_y);

                    return -1;

                }

                sub_partition_count[i]= b_sub_mb_type_info[ h->sub_mb_type[i] ].partition_count;

                h->sub_mb_type[i]=      b_sub_mb_type_info[ h->sub_mb_type[i] ].type;

            }

            if(   IS_DIRECT(h->sub_mb_type[0]) || IS_DIRECT(h->sub_mb_type[1])

               || IS_DIRECT(h->sub_mb_type[2]) || IS_DIRECT(h->sub_mb_type[3])) {

                ff_h264_pred_direct_motion(h, &mb_type);

                h->ref_cache[0][scan8[4]] =

                h->ref_cache[1][scan8[4]] =

                h->ref_cache[0][scan8[12]] =

                h->ref_cache[1][scan8[12]] = PART_NOT_AVAILABLE;

            }

        }else{

            assert(h->slice_type_nos == FF_P_TYPE); 

            for(i=0; i<4; i++){

                h->sub_mb_type[i]= get_ue_golomb_31(&s->gb);

                if(h->sub_mb_type[i] >=4){

                    av_log(h->s.avctx, AV_LOG_ERROR, "P sub_mb_type %u out of range at %d %d\n", h->sub_mb_type[i], s->mb_x, s->mb_y);

                    return -1;

                }

                sub_partition_count[i]= p_sub_mb_type_info[ h->sub_mb_type[i] ].partition_count;

                h->sub_mb_type[i]=      p_sub_mb_type_info[ h->sub_mb_type[i] ].type;

            }

        }



        for(list=0; list<h->list_count; list++){

            int ref_count= IS_REF0(mb_type) ? 1 : h->ref_count[list];

            for(i=0; i<4; i++){

                if(IS_DIRECT(h->sub_mb_type[i])) continue;

                if(IS_DIR(h->sub_mb_type[i], 0, list)){

                    unsigned int tmp;

                    if(ref_count == 1){

                        tmp= 0;

                    }else if(ref_count == 2){

                        tmp= get_bits1(&s->gb)^1;

                    }else{

                        tmp= get_ue_golomb_31(&s->gb);

                        if(tmp>=ref_count){

                            av_log(h->s.avctx, AV_LOG_ERROR, "ref %u overflow\n", tmp);

                            return -1;

                        }

                    }

                    ref[list][i]= tmp;

                }else{

                 

                    ref[list][i] = -1;

                }

            }

        }



        if(dct8x8_allowed)

            dct8x8_allowed = get_dct8x8_allowed(h);



        for(list=0; list<h->list_count; list++){

            for(i=0; i<4; i++){

                if(IS_DIRECT(h->sub_mb_type[i])) {

                    h->ref_cache[list][ scan8[4*i] ] = h->ref_cache[list][ scan8[4*i]+1 ];

                    continue;

                }

                h->ref_cache[list][ scan8[4*i]   ]=h->ref_cache[list][ scan8[4*i]+1 ]=

                h->ref_cache[list][ scan8[4*i]+8 ]=h->ref_cache[list][ scan8[4*i]+9 ]= ref[list][i];



                if(IS_DIR(h->sub_mb_type[i], 0, list)){

                    const int sub_mb_type= h->sub_mb_type[i];

                    const int block_width= (sub_mb_type & (MB_TYPE_16x16|MB_TYPE_16x8)) ? 2 : 1;

                    for(j=0; j<sub_partition_count[i]; j++){

                        int mx, my;

                        const int index= 4*i + block_width*j;

                        int16_t (* mv_cache)[2]= &h->mv_cache[list][ scan8[index] ];

                        pred_motion(h, index, block_width, list, h->ref_cache[list][ scan8[index] ], &mx, &my);

                        mx += get_se_golomb(&s->gb);

                        my += get_se_golomb(&s->gb);

                        tprintf(s->avctx, "final mv:%d %d\n", mx, my);



                        if(IS_SUB_8X8(sub_mb_type)){

                            mv_cache[ 1 ][0]=

                            mv_cache[ 8 ][0]= mv_cache[ 9 ][0]= mx;

                            mv_cache[ 1 ][1]=

                            mv_cache[ 8 ][1]= mv_cache[ 9 ][1]= my;

                        }else if(IS_SUB_8X4(sub_mb_type)){

                            mv_cache[ 1 ][0]= mx;

                            mv_cache[ 1 ][1]= my;

                        }else if(IS_SUB_4X8(sub_mb_type)){

                            mv_cache[ 8 ][0]= mx;

                            mv_cache[ 8 ][1]= my;

                        }

                        mv_cache[ 0 ][0]= mx;

                        mv_cache[ 0 ][1]= my;

                    }

                }else{

                    uint32_t *p= (uint32_t *)&h->mv_cache[list][ scan8[4*i] ][0];

                    p[0] = p[1]=

                    p[8] = p[9]= 0;

                }

            }

        }

    }else if(IS_DIRECT(mb_type)){

        ff_h264_pred_direct_motion(h, &mb_type);

        dct8x8_allowed &= h->sps.direct_8x8_inference_flag;

    }else{

        int list, mx, my, i;

          we should set ref_idx_l? to 0 if we use that later ...

        if(IS_16X16(mb_type)){

            for(list=0; list<h->list_count; list++){

                    unsigned int val;

                    if(IS_DIR(mb_type, 0, list)){

                        if(h->ref_count[list]==1){

                            val= 0;

                        }else if(h->ref_count[list]==2){

                            val= get_bits1(&s->gb)^1;

                        }else{

                            val= get_ue_golomb_31(&s->gb);

                            if(val >= h->ref_count[list]){

                                av_log(h->s.avctx, AV_LOG_ERROR, "ref %u overflow\n", val);

                                return -1;

                            }

                        }

                    }else

                        val= LIST_NOT_USED&0xFF;

                    fill_rectangle(&h->ref_cache[list][ scan8[0] ], 4, 4, 8, val, 1);

            }

            for(list=0; list<h->list_count; list++){

                unsigned int val;

                if(IS_DIR(mb_type, 0, list)){

                    pred_motion(h, 0, 4, list, h->ref_cache[list][ scan8[0] ], &mx, &my);

                    mx += get_se_golomb(&s->gb);

                    my += get_se_golomb(&s->gb);

                    tprintf(s->avctx, "final mv:%d %d\n", mx, my);



                    val= pack16to32(mx,my);

                }else

                    val=0;

                fill_rectangle(h->mv_cache[list][ scan8[0] ], 4, 4, 8, val, 4);

            }

        }

        else if(IS_16X8(mb_type)){

            for(list=0; list<h->list_count; list++){

                    for(i=0; i<2; i++){

                        unsigned int val;

                        if(IS_DIR(mb_type, i, list)){

                            if(h->ref_count[list] == 1){

                                val= 0;

                            }else if(h->ref_count[list] == 2){

                                val= get_bits1(&s->gb)^1;

                            }else{

                                val= get_ue_golomb_31(&s->gb);

                                if(val >= h->ref_count[list]){

                                    av_log(h->s.avctx, AV_LOG_ERROR, "ref %u overflow\n", val);

                                    return -1;

                                }

                            }

                        }else

                            val= LIST_NOT_USED&0xFF;

                        fill_rectangle(&h->ref_cache[list][ scan8[0] + 16*i ], 4, 2, 8, val, 1);

                    }

            }

            for(list=0; list<h->list_count; list++){

                for(i=0; i<2; i++){

                    unsigned int val;

                    if(IS_DIR(mb_type, i, list)){

                        pred_16x8_motion(h, 8*i, list, h->ref_cache[list][scan8[0] + 16*i], &mx, &my);

                        mx += get_se_golomb(&s->gb);

                        my += get_se_golomb(&s->gb);

                        tprintf(s->avctx, "final mv:%d %d\n", mx, my);



                        val= pack16to32(mx,my);

                    }else

                        val=0;

                    fill_rectangle(h->mv_cache[list][ scan8[0] + 16*i ], 4, 2, 8, val, 4);

                }

            }

        }else{

            assert(IS_8X16(mb_type));

            for(list=0; list<h->list_count; list++){

                    for(i=0; i<2; i++){

                        unsigned int val;

                        if(IS_DIR(mb_type, i, list)){  optimize

                            if(h->ref_count[list]==1){

                                val= 0;

                            }else if(h->ref_count[list]==2){

                                val= get_bits1(&s->gb)^1;

                            }else{

                                val= get_ue_golomb_31(&s->gb);

                                if(val >= h->ref_count[list]){

                                    av_log(h->s.avctx, AV_LOG_ERROR, "ref %u overflow\n", val);

                                    return -1;

                                }

                            }

                        }else

                            val= LIST_NOT_USED&0xFF;

                        fill_rectangle(&h->ref_cache[list][ scan8[0] + 2*i ], 2, 4, 8, val, 1);

                    }

            }

            for(list=0; list<h->list_count; list++){

                for(i=0; i<2; i++){

                    unsigned int val;

                    if(IS_DIR(mb_type, i, list)){

                        pred_8x16_motion(h, i*4, list, h->ref_cache[list][ scan8[0] + 2*i ], &mx, &my);

                        mx += get_se_golomb(&s->gb);

                        my += get_se_golomb(&s->gb);

                        tprintf(s->avctx, "final mv:%d %d\n", mx, my);



                        val= pack16to32(mx,my);

                    }else

                        val=0;

                    fill_rectangle(h->mv_cache[list][ scan8[0] + 2*i ], 2, 4, 8, val, 4);

                }

            }

        }

    }



    if(IS_INTER(mb_type))

        write_back_motion(h, mb_type);



    if(!IS_INTRA16x16(mb_type)){

        cbp= get_ue_golomb(&s->gb);

        if(cbp > 47){

            av_log(h->s.avctx, AV_LOG_ERROR, "cbp too large (%u) at %d %d\n", cbp, s->mb_x, s->mb_y);

            return -1;

        }



        if(CHROMA){

            if(IS_INTRA4x4(mb_type)) cbp= golomb_to_intra4x4_cbp[cbp];

            else                     cbp= golomb_to_inter_cbp   [cbp];

        }else{

            if(IS_INTRA4x4(mb_type)) cbp= golomb_to_intra4x4_cbp_gray[cbp];

            else                     cbp= golomb_to_inter_cbp_gray[cbp];

        }

    }

    h->cbp = cbp;



    if(dct8x8_allowed && (cbp&15) && !IS_INTRA(mb_type)){

        if(get_bits1(&s->gb)){

            mb_type |= MB_TYPE_8x8DCT;

            h->cbp_table[mb_xy]= cbp;

        }

    }

    s->current_picture.mb_type[mb_xy]= mb_type;



    if(cbp || IS_INTRA16x16(mb_type)){

        int i8x8, i4x4, chroma_idx;

        int dquant;

        GetBitContext *gb= IS_INTRA(mb_type) ? h->intra_gb_ptr : h->inter_gb_ptr;

        const uint8_t *scan, *scan8x8, *dc_scan;







        if(IS_INTERLACED(mb_type)){

            scan8x8= s->qscale ? h->field_scan8x8_cavlc : h->field_scan8x8_cavlc_q0;

            scan= s->qscale ? h->field_scan : h->field_scan_q0;

            dc_scan= luma_dc_field_scan;

        }else{

            scan8x8= s->qscale ? h->zigzag_scan8x8_cavlc : h->zigzag_scan8x8_cavlc_q0;

            scan= s->qscale ? h->zigzag_scan : h->zigzag_scan_q0;

            dc_scan= luma_dc_zigzag_scan;

        }



        dquant= get_se_golomb(&s->gb);



        if( dquant > 25 || dquant < -26 ){

            av_log(h->s.avctx, AV_LOG_ERROR, "dquant out of range (%d) at %d %d\n", dquant, s->mb_x, s->mb_y);

            return -1;

        }



        s->qscale += dquant;

        if(((unsigned)s->qscale) > 51){

            if(s->qscale<0) s->qscale+= 52;

            else            s->qscale-= 52;

        }



        h->chroma_qp[0]= get_chroma_qp(h, 0, s->qscale);

        h->chroma_qp[1]= get_chroma_qp(h, 1, s->qscale);

        if(IS_INTRA16x16(mb_type)){

            if( decode_residual(h, h->intra_gb_ptr, h->mb, LUMA_DC_BLOCK_INDEX, dc_scan, h->dequant4_coeff[0][s->qscale], 16) < 0){

                return -1;  continue if partitioned and other return -1 too

            }



            assert((cbp&15) == 0 || (cbp&15) == 15);



            if(cbp&15){

                for(i8x8=0; i8x8<4; i8x8++){

                    for(i4x4=0; i4x4<4; i4x4++){

                        const int index= i4x4 + 4*i8x8;

                        if( decode_residual(h, h->intra_gb_ptr, h->mb + 16*index, index, scan + 1, h->dequant4_coeff[0][s->qscale], 15) < 0 ){

                            return -1;

                        }

                    }

                }

            }else{

                fill_rectangle(&h->non_zero_count_cache[scan8[0]], 4, 4, 8, 0, 1);

            }

        }else{

            for(i8x8=0; i8x8<4; i8x8++){

                if(cbp & (1<<i8x8)){

                    if(IS_8x8DCT(mb_type)){

                        DCTELEM *buf = &h->mb[64*i8x8];

                        uint8_t *nnz;

                        for(i4x4=0; i4x4<4; i4x4++){

                            if( decode_residual(h, gb, buf, i4x4+4*i8x8, scan8x8+16*i4x4,

                                                h->dequant8_coeff[IS_INTRA( mb_type ) ? 0:1][s->qscale], 16) <0 )

                                return -1;

                        }

                        nnz= &h->non_zero_count_cache[ scan8[4*i8x8] ];

                        nnz[0] += nnz[1] + nnz[8] + nnz[9];

                    }else{

                        for(i4x4=0; i4x4<4; i4x4++){

                            const int index= i4x4 + 4*i8x8;



                            if( decode_residual(h, gb, h->mb + 16*index, index, scan, h->dequant4_coeff[IS_INTRA( mb_type ) ? 0:3][s->qscale], 16) <0 ){

                                return -1;

                            }

                        }

                    }

                }else{

                    uint8_t * const nnz= &h->non_zero_count_cache[ scan8[4*i8x8] ];

                    nnz[0] = nnz[1] = nnz[8] = nnz[9] = 0;

                }

            }

        }



        if(cbp&0x30){

            for(chroma_idx=0; chroma_idx<2; chroma_idx++)

                if( decode_residual(h, gb, h->mb + 256 + 16*4*chroma_idx, CHROMA_DC_BLOCK_INDEX, chroma_dc_scan, NULL, 4) < 0){

                    return -1;

                }

        }



        if(cbp&0x20){

            for(chroma_idx=0; chroma_idx<2; chroma_idx++){

                const uint32_t *qmul = h->dequant4_coeff[chroma_idx+1+(IS_INTRA( mb_type ) ? 0:3)][h->chroma_qp[chroma_idx]];

                for(i4x4=0; i4x4<4; i4x4++){

                    const int index= 16 + 4*chroma_idx + i4x4;

                    if( decode_residual(h, gb, h->mb + 16*index, index, scan + 1, qmul, 15) < 0){

                        return -1;

                    }

                }

            }

        }else{

            uint8_t * const nnz= &h->non_zero_count_cache[0];

            nnz[ scan8[16]+0 ] = nnz[ scan8[16]+1 ] =nnz[ scan8[16]+8 ] =nnz[ scan8[16]+9 ] =

            nnz[ scan8[20]+0 ] = nnz[ scan8[20]+1 ] =nnz[ scan8[20]+8 ] =nnz[ scan8[20]+9 ] = 0;

        }

    }else{

        uint8_t * const nnz= &h->non_zero_count_cache[0];

        fill_rectangle(&nnz[scan8[0]], 4, 4, 8, 0, 1);

        nnz[ scan8[16]+0 ] = nnz[ scan8[16]+1 ] =nnz[ scan8[16]+8 ] =nnz[ scan8[16]+9 ] =

        nnz[ scan8[20]+0 ] = nnz[ scan8[20]+1 ] =nnz[ scan8[20]+8 ] =nnz[ scan8[20]+9 ] = 0;

    }

    s->current_picture.qscale_table[mb_xy]= s->qscale;

    write_back_non_zero_count(h);



    if(MB_MBAFF){

        h->ref_count[0] >>= 1;

        h->ref_count[1] >>= 1;

    }



    return 0;

}
