h263.c

Trolltech公司发布的图形界面操作系统。可在qt-embedded-2.3.7平台上编译为嵌入式图形界面操作系统。

        int cbp = 0;
        for (i = 0; i < 6; i++) {
            if (s->block_last_index[i] >= 0)
                cbp |= 1 << (5 - i);
        }

        if(s->pict_type==B_TYPE){
            static const int mb_type_table[8]= {-1, 2, 3, 1,-1,-1,-1, 0}; /* convert from mv_dir to type */
            int mb_type=  mb_type_table[s->mv_dir];
            
            if(s->mb_x==0){
                s->last_mv[0][0][0]= 
                s->last_mv[0][0][1]= 
                s->last_mv[1][0][0]= 
                s->last_mv[1][0][1]= 0;
            }
            
            assert(s->dquant>=-2 && s->dquant<=2);
            assert((s->dquant&1)==0);
            assert(mb_type>=0);

            /* nothing to do if this MB was skiped in the next P Frame */
            if(s->mbskip_table[s->mb_y * s->mb_width + s->mb_x]){ //FIXME avoid DCT & ...
                s->skip_count++;
                s->mv[0][0][0]= 
                s->mv[0][0][1]= 
                s->mv[1][0][0]= 
                s->mv[1][0][1]= 0;
                s->mv_dir= MV_DIR_FORWARD; //doesnt matter
                s->qscale -= s->dquant;
                return;
            }

            if ((cbp | motion_x | motion_y | mb_type) ==0) {
                /* direct MB with MV={0,0} */
                assert(s->dquant==0);
                
                put_bits(&s->pb, 1, 1); /* mb not coded modb1=1 */

                if(interleaved_stats){
                    s->misc_bits++;
                    s->last_bits++;
                }
                s->skip_count++;
                return;
            }
            put_bits(&s->pb, 1, 0);	/* mb coded modb1=0 */
            put_bits(&s->pb, 1, cbp ? 0 : 1); /* modb2 */ //FIXME merge
            put_bits(&s->pb, mb_type+1, 1); // this table is so simple that we dont need it :)
            if(cbp) put_bits(&s->pb, 6, cbp);
            
            if(cbp && mb_type){
                if(s->dquant)
                    put_bits(&s->pb, 2, (s->dquant>>2)+3);
                else
                    put_bits(&s->pb, 1, 0);
            }else
                s->qscale -= s->dquant;
            
            if(!s->progressive_sequence){
                if(cbp)
                    put_bits(&s->pb, 1, s->interlaced_dct);
                if(mb_type) // not diect mode
                    put_bits(&s->pb, 1, 0); // no interlaced ME yet
            }

            if(interleaved_stats){
                bits= get_bit_count(&s->pb);
                s->misc_bits+= bits - s->last_bits;
                s->last_bits=bits;
            }

            switch(mb_type)
            {
            case 0: /* direct */
                h263_encode_motion(s, motion_x, 1);
                h263_encode_motion(s, motion_y, 1);                
                s->b_count++;
                s->f_count++;
                break;
            case 1: /* bidir */
                h263_encode_motion(s, s->mv[0][0][0] - s->last_mv[0][0][0], s->f_code);
                h263_encode_motion(s, s->mv[0][0][1] - s->last_mv[0][0][1], s->f_code);
                h263_encode_motion(s, s->mv[1][0][0] - s->last_mv[1][0][0], s->b_code);
                h263_encode_motion(s, s->mv[1][0][1] - s->last_mv[1][0][1], s->b_code);
                s->last_mv[0][0][0]= s->mv[0][0][0];
                s->last_mv[0][0][1]= s->mv[0][0][1];
                s->last_mv[1][0][0]= s->mv[1][0][0];
                s->last_mv[1][0][1]= s->mv[1][0][1];
                s->b_count++;
                s->f_count++;
                break;
            case 2: /* backward */
                h263_encode_motion(s, motion_x - s->last_mv[1][0][0], s->b_code);
                h263_encode_motion(s, motion_y - s->last_mv[1][0][1], s->b_code);
                s->last_mv[1][0][0]= motion_x;
                s->last_mv[1][0][1]= motion_y;
                s->b_count++;
                break;
            case 3: /* forward */
                h263_encode_motion(s, motion_x - s->last_mv[0][0][0], s->f_code);
                h263_encode_motion(s, motion_y - s->last_mv[0][0][1], s->f_code);
                s->last_mv[0][0][0]= motion_x;
                s->last_mv[0][0][1]= motion_y;
                s->f_count++;
                break;
            default:
                printf("unknown mb type\n");
                return;
            }

            if(interleaved_stats){
                bits= get_bit_count(&s->pb);
                s->mv_bits+= bits - s->last_bits;
                s->last_bits=bits;
            }

            /* encode each block */
            for (i = 0; i < 6; i++) {
                mpeg4_encode_block(s, block[i], i, 0, s->intra_scantable.permutated, NULL, &s->pb);
            }

            if(interleaved_stats){
                bits= get_bit_count(&s->pb);
                s->p_tex_bits+= bits - s->last_bits;
                s->last_bits=bits;
            }
        }else{ /* s->pict_type==B_TYPE */
            if ((cbp | motion_x | motion_y | s->dquant) == 0 && s->mv_type==MV_TYPE_16X16) {
                /* check if the B frames can skip it too, as we must skip it if we skip here 
                   why didnt they just compress the skip-mb bits instead of reusing them ?! */
                if(s->max_b_frames>0){
                    int i;
                    int x,y, offset;
                    uint8_t *p_pic;

                    x= s->mb_x*16;
                    y= s->mb_y*16;
                    if(x+16 > s->width)  x= s->width-16;
                    if(y+16 > s->height) y= s->height-16;

                    offset= x + y*s->linesize;
                    p_pic= s->new_picture[0] + offset;
                    
                    s->mb_skiped=1;
                    for(i=0; i<s->max_b_frames; i++){
                        uint8_t *b_pic;
                        int diff;

                        if(s->coded_order[i+1].pict_type!=B_TYPE) break;

                        b_pic= s->coded_order[i+1].picture[0] + offset;
			diff= s->dsp.pix_abs16x16(p_pic, b_pic, s->linesize);
                        if(diff>s->qscale*70){ //FIXME check that 70 is optimal
                            s->mb_skiped=0;
                            break;
                        }
                    }
                }else
                    s->mb_skiped=1; 

                if(s->mb_skiped==1){
                    /* skip macroblock */
                    put_bits(&s->pb, 1, 1);

                    if(interleaved_stats){
                        s->misc_bits++;
                        s->last_bits++;
                    }
                    s->skip_count++;
                    return;
                }
            }

            put_bits(&s->pb, 1, 0);	/* mb coded */
            if(s->mv_type==MV_TYPE_16X16){
                cbpc = cbp & 3;
                if(s->dquant) cbpc+= 8;
                put_bits(&s->pb,
                        inter_MCBPC_bits[cbpc],
                        inter_MCBPC_code[cbpc]);

                cbpy = cbp >> 2;
                cbpy ^= 0xf;
                put_bits(pb2, cbpy_tab[cbpy][1], cbpy_tab[cbpy][0]);
                if(s->dquant)
                    put_bits(pb2, 2, dquant_code[s->dquant+2]);

                if(!s->progressive_sequence){
                    if(cbp)
                        put_bits(pb2, 1, s->interlaced_dct);
                    put_bits(pb2, 1, 0); // no interlaced ME yet
                }
                    
                if(interleaved_stats){
                    bits= get_bit_count(&s->pb);
                    s->misc_bits+= bits - s->last_bits;
                    s->last_bits=bits;
                }

                /* motion vectors: 16x16 mode */
                h263_pred_motion(s, 0, &pred_x, &pred_y);
            
                h263_encode_motion(s, motion_x - pred_x, s->f_code);
                h263_encode_motion(s, motion_y - pred_y, s->f_code);
            }else{
                cbpc = (cbp & 3)+16;
                put_bits(&s->pb,
                        inter_MCBPC_bits[cbpc],
                        inter_MCBPC_code[cbpc]);
                cbpy = cbp >> 2;
                cbpy ^= 0xf;
                put_bits(pb2, cbpy_tab[cbpy][1], cbpy_tab[cbpy][0]);

                if(!s->progressive_sequence){
                    if(cbp)
                        put_bits(pb2, 1, s->interlaced_dct);
                }
    
                if(interleaved_stats){
                    bits= get_bit_count(&s->pb);
                    s->misc_bits+= bits - s->last_bits;
                    s->last_bits=bits;
                }

                for(i=0; i<4; i++){
                    /* motion vectors: 8x8 mode*/
                    h263_pred_motion(s, i, &pred_x, &pred_y);

                    h263_encode_motion(s, s->motion_val[ s->block_index[i] ][0] - pred_x, s->f_code);
                    h263_encode_motion(s, s->motion_val[ s->block_index[i] ][1] - pred_y, s->f_code);
                }
            }

            if(interleaved_stats){ 
                bits= get_bit_count(&s->pb);
                s->mv_bits+= bits - s->last_bits;
                s->last_bits=bits;
            }

            /* encode each block */
            for (i = 0; i < 6; i++) {
                mpeg4_encode_block(s, block[i], i, 0, s->intra_scantable.permutated, NULL, tex_pb);
            }

            if(interleaved_stats){
                bits= get_bit_count(&s->pb);
                s->p_tex_bits+= bits - s->last_bits;
                s->last_bits=bits;
            }
            s->f_count++;
        }
    } else {
        int cbp;
        int dc_diff[6];   //dc values with the dc prediction subtracted 
        int dir[6];  //prediction direction
        int zigzag_last_index[6];
        UINT8 *scan_table[6];

        for(i=0; i<6; i++){
            const int level= block[i][0];
            UINT16 *dc_ptr;

            dc_diff[i]= level - ff_mpeg4_pred_dc(s, i, &dc_ptr, &dir[i]);
            if (i < 4) {
                *dc_ptr = level * s->y_dc_scale;
            } else {
                *dc_ptr = level * s->c_dc_scale;
            }
        }

        s->ac_pred= decide_ac_pred(s, block, dir);

        if(s->ac_pred){
            for(i=0; i<6; i++){
                UINT8 *st;
                int last_index;

                mpeg4_inv_pred_ac(s, block[i], i, dir[i]);
                if (dir[i]==0) st = s->intra_v_scantable.permutated; /* left */
                else           st = s->intra_h_scantable.permutated; /* top */

                for(last_index=63; last_index>=0; last_index--) //FIXME optimize
                    if(block[i][st[last_index]]) break;
                zigzag_last_index[i]= s->block_last_index[i];
                s->block_last_index[i]= last_index;
                scan_table[i]= st;
            }
        }else{
            for(i=0; i<6; i++)
                scan_table[i]= s->intra_scantable.permutated;
        }

        /* compute cbp */
        cbp = 0;
        for (i = 0; i < 6; i++) {
            if (s->block_last_index[i] >= 1)
                cbp |= 1 << (5 - i);
        }

        cbpc = cbp & 3;
        if (s->pict_type == I_TYPE) {
            if(s->dquant) cbpc+=4;
            put_bits(&s->pb,
                intra_MCBPC_bits[cbpc],
                intra_MCBPC_code[cbpc]);
        } else {
            if(s->dquant) cbpc+=8;
            put_bits(&s->pb, 1, 0);	/* mb coded */
            put_bits(&s->pb,
                inter_MCBPC_bits[cbpc + 4],
                inter_MCBPC_code[cbpc + 4]);
        }
        put_bits(pb2, 1, s->ac_pred);
        cbpy = cbp >> 2;
        put_bits(pb2, cbpy_tab[cbpy][1], cbpy_tab[cbpy][0]);
        if(s->dquant)
            put_bits(dc_pb, 2, dquant_code[s->dquant+2]);

        if(!s->progressive_sequence){
            put_bits(dc_pb, 1, s->interlaced_dct);
        }

        if(interleaved_stats){
            bits= get_bit_count(&s->pb);
            s->misc_bits+= bits - s->last_bits;
            s->last_bits=bits;
        }

        /* encode each block */
        for (i = 0; i < 6; i++) {
            mpeg4_encode_block(s, block[i], i, dc_diff[i], scan_table[i], dc_pb, tex_pb);
        }

        if(interleaved_stats){
            bits= get_bit_count(&s->pb);
            s->i_tex_bits+= bits - s->last_bits;
            s->last_bits=bits;
        }
        s->i_count++;

        /* restore ac coeffs & last_index stuff if we messed them up with the prediction */
        if(s->ac_pred){
            for(i=0; i<6; i++){
                int j;    
                INT16 *ac_val;

                ac_val = s->ac_val[0][0] + s->block_index[i] * 16;

                if(dir[i]){
                    for(j=1; j<8; j++) 
                        block[i][s->idct_permutation[j   ]]= ac_val[j+8];
                }else{
                    for(j=1; j<8; j++) 
                        block[i][s->idct_permutation[j<<3]]= ac_val[j  ];
                }
                s->block_last_index[i]= zigzag_last_index[i];
            }
        }
    }
}

void h263_encode_mb(MpegEncContext * s,
		    DCTELEM block[6][64],
		    int motion_x, int motion_y)
{
    int cbpc, cbpy, i, cbp, pred_x, pred_y;
    INT16 pred_dc;
    INT16 rec_intradc[6];
    UINT16 *dc_ptr[6];
    const int dquant_code[5]= {1,0,9,2,3};
           
    //printf("**mb x=%d y=%d\n", s->mb_x, s->mb_y);
    if (!s->mb_intra) {
        /* compute cbp */
        cbp = 0;
        for (i = 0; i < 6; i++) {
            if (s->block_last_index[i] >= 0)
                cbp |= 1 << (5 - i);
        }
        if ((cbp | motion_x | motion_y | s->dquant) == 0) {
            /* skip macroblock */
            put_bits(&s->pb, 1, 1);
            return;
        }
        put_bits(&s->pb, 1, 0);	/* mb coded */
        cbpc = cbp & 3;
        if(s->dquant) cbpc+= 8;
        put_bits(&s->pb,
		    inter_MCBPC_bits[cbpc],
		    inter_MCBPC_code[cbpc]);
        cbpy = cbp >> 2;
        cbpy ^= 0xf;
        put_bits(&s->pb, cbpy_tab[cbpy][1], cbpy_tab[cbpy][0]);
        if(s->dquant)
            put_bits(&s->pb, 2, dquant_code[s->dquant+2]);

        /* motion vectors: 16x16 mode only now */
        h263_pred_motion(s, 0, &pred_x, &pred_y);
      
        if (!s->umvplus) {  
            h263_encode_motion(s, motion_x - pred_x, s->f_code);
            h263_encode_motion(s, motion_y - pred_y, s->f_code);
        }
        else {
            h263p_encode_umotion(s, motion_x - pred_x);