h263.c

Trolltech公司发布的图形界面操作系统。可在qt-embedded-2.3.10平台上编译为嵌入式图形界面操作系统。

                /* different qscale, we must rescale */
                for(i=1; i<8; i++){
                    const int level= block[n][s->dsp.idct_permutation[i<<3]];
                    block[n][s->dsp.idct_permutation[i<<3]]= level - ROUNDED_DIV(ac_val[i]*qscale_table[xy], s->qscale);
                    ac_val1[i  ]= level;
                    ac_val1[i+8]=    block[n][s->dsp.idct_permutation[i   ]];
                }
            }
            st[n]= s->intra_v_scantable.permutated;
        }

        for(i=63; i>0; i--) //FIXME optimize
            if(block[n][ st[n][i] ]) break;
        s->block_last_index[n]= i;

        score += get_block_rate(s, block[n], s->block_last_index[n], st[n]);
    }

    return score < 0;
}

static inline void restore_ac_coeffs(MpegEncContext * s, DCTELEM block[6][64], int dir[6], uint8_t *st[6], int zigzag_last_index[6])
{
    int i, n;
    memcpy(s->block_last_index, zigzag_last_index, sizeof(int)*6);

    for(n=0; n<6; n++){
        int16_t *ac_val = s->ac_val[0][0] + s->block_index[n] * 16;

        st[n]= s->intra_scantable.permutated;
        if(dir[n]){
            /* top prediction */
            for(i=1; i<8; i++){
                block[n][s->dsp.idct_permutation[i   ]] = ac_val[i+8];
            }
        }else{
            /* left prediction */
            for(i=1; i<8; i++){
                block[n][s->dsp.idct_permutation[i<<3]]= ac_val[i  ];
            }
        }
    }
}

/**
 * modify qscale so that encoding is acually possible in h263 (limit difference to -2..2)
 */
void ff_clean_h263_qscales(MpegEncContext *s){
    int i;
    int8_t * const qscale_table= s->current_picture.qscale_table;
    
    for(i=1; i<s->mb_num; i++){
        if(qscale_table[ s->mb_index2xy[i] ] - qscale_table[ s->mb_index2xy[i-1] ] >2)
            qscale_table[ s->mb_index2xy[i] ]= qscale_table[ s->mb_index2xy[i-1] ]+2;
    }
    for(i=s->mb_num-2; i>=0; i--){
        if(qscale_table[ s->mb_index2xy[i] ] - qscale_table[ s->mb_index2xy[i+1] ] >2)
            qscale_table[ s->mb_index2xy[i] ]= qscale_table[ s->mb_index2xy[i+1] ]+2;
    }
}

/**
 * modify mb_type & qscale so that encoding is acually possible in mpeg4
 */
void ff_clean_mpeg4_qscales(MpegEncContext *s){
    int i;
    int8_t * const qscale_table= s->current_picture.qscale_table;

    ff_clean_h263_qscales(s);
    
    for(i=1; i<s->mb_num; i++){
        int mb_xy= s->mb_index2xy[i];
    
        if(qscale_table[mb_xy] != qscale_table[s->mb_index2xy[i-1]] && (s->mb_type[mb_xy]&MB_TYPE_INTER4V)){
            s->mb_type[mb_xy]&= ~MB_TYPE_INTER4V;
            s->mb_type[mb_xy]|= MB_TYPE_INTER;
        }
    }

    if(s->pict_type== B_TYPE){
        int odd=0;
        /* ok, come on, this isnt funny anymore, theres more code for handling this mpeg4 mess than
           for the actual adaptive quantization */
        
        for(i=0; i<s->mb_num; i++){
            int mb_xy= s->mb_index2xy[i];
            odd += qscale_table[mb_xy]&1;
        }
        
        if(2*odd > s->mb_num) odd=1;
        else                  odd=0;
        
        for(i=0; i<s->mb_num; i++){
            int mb_xy= s->mb_index2xy[i];
            if((qscale_table[mb_xy]&1) != odd)
                qscale_table[mb_xy]++;
            if(qscale_table[mb_xy] > 31)
                qscale_table[mb_xy]= 31;
        }            
    
        for(i=1; i<s->mb_num; i++){
            int mb_xy= s->mb_index2xy[i];
            if(qscale_table[mb_xy] != qscale_table[s->mb_index2xy[i-1]] && (s->mb_type[mb_xy]&MB_TYPE_DIRECT)){
                s->mb_type[mb_xy]&= ~MB_TYPE_DIRECT;
                s->mb_type[mb_xy]|= MB_TYPE_BIDIR;
            }
        }
    }
}

#endif //CONFIG_ENCODERS
/**
 *
 * @return the mb_type
 */
int ff_mpeg4_set_direct_mv(MpegEncContext *s, int mx, int my){
    const int mb_index= s->mb_x + s->mb_y*s->mb_stride;
    const int colocated_mb_type= s->next_picture.mb_type[mb_index]; //FIXME or next?
    int xy= s->block_index[0];
    uint16_t time_pp= s->pp_time;
    uint16_t time_pb= s->pb_time;
    int i;
    
    //FIXME avoid divides
    
    if(IS_8X8(colocated_mb_type)){
        s->mv_type = MV_TYPE_8X8;
        for(i=0; i<4; i++){
            xy= s->block_index[i];
            s->mv[0][i][0] = s->motion_val[xy][0]*time_pb/time_pp + mx;
            s->mv[0][i][1] = s->motion_val[xy][1]*time_pb/time_pp + my;
            s->mv[1][i][0] = mx ? s->mv[0][i][0] - s->motion_val[xy][0]
                                : s->motion_val[xy][0]*(time_pb - time_pp)/time_pp;
            s->mv[1][i][1] = my ? s->mv[0][i][1] - s->motion_val[xy][1] 
                                : s->motion_val[xy][1]*(time_pb - time_pp)/time_pp;
        }
        return MB_TYPE_DIRECT2 | MB_TYPE_8x8 | MB_TYPE_L0L1;
    } else if(IS_INTERLACED(colocated_mb_type)){
        s->mv_type = MV_TYPE_FIELD;
        for(i=0; i<2; i++){
            if(s->top_field_first){
                time_pp= s->pp_field_time - s->field_select_table[mb_index][i] + i;
                time_pb= s->pb_field_time - s->field_select_table[mb_index][i] + i;
            }else{
                time_pp= s->pp_field_time + s->field_select_table[mb_index][i] - i;
                time_pb= s->pb_field_time + s->field_select_table[mb_index][i] - i;
            }
            s->mv[0][i][0] = s->field_mv_table[mb_index][i][0]*time_pb/time_pp + mx;
            s->mv[0][i][1] = s->field_mv_table[mb_index][i][1]*time_pb/time_pp + my;
            s->mv[1][i][0] = mx ? s->mv[0][i][0] - s->field_mv_table[mb_index][i][0]
                                : s->field_mv_table[mb_index][i][0]*(time_pb - time_pp)/time_pp;
            s->mv[1][i][1] = my ? s->mv[0][i][1] - s->field_mv_table[mb_index][i][1] 
                                : s->field_mv_table[mb_index][i][1]*(time_pb - time_pp)/time_pp;
        }
        return MB_TYPE_DIRECT2 | MB_TYPE_16x8 | MB_TYPE_L0L1 | MB_TYPE_INTERLACED;
    }else{
        s->mv[0][0][0] = s->mv[0][1][0] = s->mv[0][2][0] = s->mv[0][3][0] = s->motion_val[xy][0]*time_pb/time_pp + mx;
        s->mv[0][0][1] = s->mv[0][1][1] = s->mv[0][2][1] = s->mv[0][3][1] = s->motion_val[xy][1]*time_pb/time_pp + my;
        s->mv[1][0][0] = s->mv[1][1][0] = s->mv[1][2][0] = s->mv[1][3][0] = mx ? s->mv[0][0][0] - s->motion_val[xy][0]
                            : s->motion_val[xy][0]*(time_pb - time_pp)/time_pp;
        s->mv[1][0][1] = s->mv[1][1][1] = s->mv[1][2][1] = s->mv[1][3][1] = my ? s->mv[0][0][1] - s->motion_val[xy][1] 
                            : s->motion_val[xy][1]*(time_pb - time_pp)/time_pp;
        if((s->avctx->workaround_bugs & FF_BUG_DIRECT_BLOCKSIZE) || !s->quarter_sample)
            s->mv_type= MV_TYPE_16X16;
        else
            s->mv_type= MV_TYPE_8X8;
        return MB_TYPE_DIRECT2 | MB_TYPE_16x16 | MB_TYPE_L0L1; //Note see prev line
    }
}

void ff_h263_update_motion_val(MpegEncContext * s){
    const int mb_xy = s->mb_y * s->mb_stride + s->mb_x;
               //FIXME a lot of thet is only needed for !low_delay
    const int wrap = s->block_wrap[0];
    const int xy = s->block_index[0];
    
    s->current_picture.mbskip_table[mb_xy]= s->mb_skiped; 

    if(s->mv_type != MV_TYPE_8X8){
        int motion_x, motion_y;
        if (s->mb_intra) {
            motion_x = 0;
            motion_y = 0;
        } else if (s->mv_type == MV_TYPE_16X16) {
            motion_x = s->mv[0][0][0];
            motion_y = s->mv[0][0][1];
        } else /*if (s->mv_type == MV_TYPE_FIELD)*/ {
            int i;
            motion_x = s->mv[0][0][0] + s->mv[0][1][0];
            motion_y = s->mv[0][0][1] + s->mv[0][1][1];
            motion_x = (motion_x>>1) | (motion_x&1);
            for(i=0; i<2; i++){
                s->field_mv_table[mb_xy][i][0]= s->mv[0][i][0];
                s->field_mv_table[mb_xy][i][1]= s->mv[0][i][1];
                s->field_select_table[mb_xy][i]= s->field_select[0][i];
            }
        }
        
        /* no update if 8X8 because it has been done during parsing */
        s->motion_val[xy][0] = motion_x;
        s->motion_val[xy][1] = motion_y;
        s->motion_val[xy + 1][0] = motion_x;
        s->motion_val[xy + 1][1] = motion_y;
        s->motion_val[xy + wrap][0] = motion_x;
        s->motion_val[xy + wrap][1] = motion_y;
        s->motion_val[xy + 1 + wrap][0] = motion_x;
        s->motion_val[xy + 1 + wrap][1] = motion_y;
    }

    if(s->encoding){ //FIXME encoding MUST be cleaned up
        if (s->mv_type == MV_TYPE_8X8) 
            s->current_picture.mb_type[mb_xy]= MB_TYPE_L0 | MB_TYPE_8x8;
        else
            s->current_picture.mb_type[mb_xy]= MB_TYPE_L0 | MB_TYPE_16x16;
    }
}

#ifdef CONFIG_ENCODERS

static inline int get_p_cbp(MpegEncContext * s,
                      DCTELEM block[6][64],
                      int motion_x, int motion_y){
    int cbp, i;

    if(s->flags & CODEC_FLAG_CBP_RD){
        int best_cbpy_score= INT_MAX;
        int best_cbpc_score= INT_MAX;
        int cbpc = (-1), cbpy= (-1);
        const int offset= (s->mv_type==MV_TYPE_16X16 ? 0 : 16) + (s->dquant ? 8 : 0);
        const int lambda= s->lambda2 >> (FF_LAMBDA_SHIFT - 6);

        for(i=0; i<4; i++){
            int score= inter_MCBPC_bits[i + offset] * lambda;
            if(i&1) score += s->coded_score[5];
            if(i&2) score += s->coded_score[4];

            if(score < best_cbpc_score){
                best_cbpc_score= score;
                cbpc= i;
            }
        }

        for(i=0; i<16; i++){
            int score= cbpy_tab[i ^ 0xF][1] * lambda;
            if(i&1) score += s->coded_score[3];
            if(i&2) score += s->coded_score[2];
            if(i&4) score += s->coded_score[1];
            if(i&8) score += s->coded_score[0];

            if(score < best_cbpy_score){
                best_cbpy_score= score;
                cbpy= i;
            }
        }
        cbp= cbpc + 4*cbpy;
        if ((motion_x | motion_y | s->dquant) == 0 && s->mv_type==MV_TYPE_16X16){
            if(best_cbpy_score + best_cbpc_score + 2*lambda >= 0)
                cbp= 0;
        }

        for (i = 0; i < 6; i++) {
            if (s->block_last_index[i] >= 0 && ((cbp >> (5 - i))&1)==0 ){
                s->block_last_index[i]= -1;
                memset(s->block[i], 0, sizeof(DCTELEM)*64);
            }
        }
    }else{
        cbp= 0;
        for (i = 0; i < 6; i++) {
            if (s->block_last_index[i] >= 0)
                cbp |= 1 << (5 - i);
        }
    }
    return cbp;
}

static inline int get_b_cbp(MpegEncContext * s, DCTELEM block[6][64],
                            int motion_x, int motion_y, int mb_type){
    int cbp=0, i;

    if(s->flags & CODEC_FLAG_CBP_RD){
        int score=0;
        const int lambda= s->lambda2 >> (FF_LAMBDA_SHIFT - 6);
        
        for(i=0; i<6; i++){
            if(s->coded_score[i] < 0){
                score += s->coded_score[i];
                cbp |= 1 << (5 - i);
            }
        }
        
        if(cbp){
            int zero_score= -6;
            if ((motion_x | motion_y | s->dquant | mb_type) == 0){
                zero_score-= 4; //2*MV + mb_type + cbp bit
            }

            zero_score*= lambda;
            if(zero_score <= score){
                cbp=0;
            }
        }

        for (i = 0; i < 6; i++) {
            if (s->block_last_index[i] >= 0 && ((cbp >> (5 - i))&1)==0 ){
                s->block_last_index[i]= -1;
                memset(s->block[i], 0, sizeof(DCTELEM)*64);
            }
        }
    }else{
        for (i = 0; i < 6; i++) {
            if (s->block_last_index[i] >= 0)
                cbp |= 1 << (5 - i);
        }
    }
    return cbp;
}

void mpeg4_encode_mb(MpegEncContext * s,
		    DCTELEM block[6][64],
		    int motion_x, int motion_y)
{
    int cbpc, cbpy, pred_x, pred_y;
    PutBitContext * const pb2    = s->data_partitioning                         ? &s->pb2    : &s->pb;
    PutBitContext * const tex_pb = s->data_partitioning && s->pict_type!=B_TYPE ? &s->tex_pb : &s->pb;
    PutBitContext * const dc_pb  = s->data_partitioning && s->pict_type!=I_TYPE ? &s->pb2    : &s->pb;
    const int interleaved_stats= (s->flags&CODEC_FLAG_PASS1) && !s->data_partitioning ? 1 : 0;
    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 */
        int i, cbp;
        
        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->next_picture.mbskip_table[s->mb_y * s->mb_stride + 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;
//                s->mb_skiped=1;

                return;
            }
            
            cbp= get_b_cbp(s, block, motion_x, motion_y, mb_type);
            
            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;