h263.c

从FFMPEG转换而来的H264解码程序,VC下编译..

           +h263_get_motion_length(s, y, f_code));
    }else{
        ff_h263_encode_motion(s, x, f_code);
        ff_h263_encode_motion(s, y, f_code);
    }
}

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;
}

static inline void mpeg4_encode_blocks(MpegEncContext * s, DCTELEM block[6][64], int intra_dc[6],
                               uint8_t **scan_table, PutBitContext *dc_pb, PutBitContext *ac_pb){
    int i;

    if(scan_table){
        if(s->flags2 & CODEC_FLAG2_NO_OUTPUT){
            for (i = 0; i < 6; i++) {
                skip_put_bits(&s->pb, mpeg4_get_block_length(s, block[i], i, intra_dc[i], scan_table[i]));
            }
        }else{
            /* encode each block */
            for (i = 0; i < 6; i++) {
                mpeg4_encode_block(s, block[i], i, intra_dc[i], scan_table[i], dc_pb, ac_pb);
            }
        }
    }else{
        if(s->flags2 & CODEC_FLAG2_NO_OUTPUT){
            for (i = 0; i < 6; i++) {
                skip_put_bits(&s->pb, mpeg4_get_block_length(s, block[i], i, 0, s->intra_scantable.permutated));
            }
        }else{
            /* encode each block */
            for (i = 0; i < 6; i++) {
                mpeg4_encode_block(s, block[i], i, 0, s->intra_scantable.permutated, dc_pb, ac_pb);
            }
        }
    }
}

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) {
        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){
                for(i=0; i<2; i++){
                    s->last_mv[i][0][0]=
                    s->last_mv[i][0][1]=
                    s->last_mv[i][1][0]=
                    s->last_mv[i][1][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 skipped 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; //doesn't matter
                s->qscale -= s->dquant;
//                s->mb_skipped=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 don't 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 direct mode
                    put_bits(&s->pb, 1, s->mv_type == MV_TYPE_FIELD);
            }

            if(interleaved_stats){
                s->misc_bits+= get_bits_diff(s);
            }

            if(mb_type == 0){
                assert(s->mv_dir & MV_DIRECT);
                ff_h263_encode_motion_vector(s, motion_x, motion_y, 1);
                s->b_count++;
                s->f_count++;
            }else{
                assert(mb_type > 0 && mb_type < 4);
                if(s->mv_type != MV_TYPE_FIELD){
                    if(s->mv_dir & MV_DIR_FORWARD){
                        ff_h263_encode_motion_vector(s, s->mv[0][0][0] - s->last_mv[0][0][0],
                                                        s->mv[0][0][1] - s->last_mv[0][0][1], s->f_code);
                        s->last_mv[0][0][0]= s->last_mv[0][1][0]= s->mv[0][0][0];
                        s->last_mv[0][0][1]= s->last_mv[0][1][1]= s->mv[0][0][1];
                        s->f_count++;
                    }
                    if(s->mv_dir & MV_DIR_BACKWARD){
                        ff_h263_encode_motion_vector(s, s->mv[1][0][0] - s->last_mv[1][0][0],
                                                        s->mv[1][0][1] - s->last_mv[1][0][1], s->b_code);
                        s->last_mv[1][0][0]= s->last_mv[1][1][0]= s->mv[1][0][0];
                        s->last_mv[1][0][1]= s->last_mv[1][1][1]= s->mv[1][0][1];
                        s->b_count++;
                    }
                }else{
                    if(s->mv_dir & MV_DIR_FORWARD){
                        put_bits(&s->pb, 1, s->field_select[0][0]);
                        put_bits(&s->pb, 1, s->field_select[0][1]);
                    }
                    if(s->mv_dir & MV_DIR_BACKWARD){
                        put_bits(&s->pb, 1, s->field_select[1][0]);
                        put_bits(&s->pb, 1, s->field_select[1][1]);
                    }
                    if(s->mv_dir & MV_DIR_FORWARD){
                        for(i=0; i<2; i++){
                            ff_h263_encode_motion_vector(s, s->mv[0][i][0] - s->last_mv[0][i][0]  ,
                                                            s->mv[0][i][1] - s->last_mv[0][i][1]/2, s->f_code);
                            s->last_mv[0][i][0]= s->mv[0][i][0];
                            s->last_mv[0][i][1]= s->mv[0][i][1]*2;
                        }
                        s->f_count++;
                    }
                    if(s->mv_dir & MV_DIR_BACKWARD){
                        for(i=0; i<2; i++){
                            ff_h263_encode_motion_vector(s, s->mv[1][i][0] - s->last_mv[1][i][0]  ,
                                                            s->mv[1][i][1] - s->last_mv[1][i][1]/2, s->b_code);
                            s->last_mv[1][i][0]= s->mv[1][i][0];
                            s->last_mv[1][i][1]= s->mv[1][i][1]*2;
                        }
                        s->b_count++;
                    }
                }
            }

            if(interleaved_stats){
                s->mv_bits+= get_bits_diff(s);
            }

            mpeg4_encode_blocks(s, block, NULL, NULL, NULL, &s->pb);

            if(interleaved_stats){
                s->p_tex_bits+= get_bits_diff(s);
            }

        }else{ /* s->pict_type==B_TYPE */
            cbp= get_p_cbp(s, block, motion_x, motion_y);

            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 didn't 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.data[0] + offset;

                    s->mb_skipped=1;
                    for(i=0; i<s->max_b_frames; i++){
                        uint8_t *b_pic;
                        int diff;
                        Picture *pic= s->reordered_input_picture[i+1];

                        if(pic==NULL || pic->pict_type!=B_TYPE) break;

                        b_pic= pic->data[0] + offset;
                        if(pic->type != FF_BUFFER_TYPE_SHARED)
                            b_pic+= INPLACE_OFFSET;
                        diff= s->dsp.sad[0](NULL, p_pic, b_pic, s->linesize, 16);
                        if(diff>s->qscale*70){ //FIXME check that 70 is optimal
                            s->mb_skipped=0;
                            break;
                        }
                    }
                }else
                    s->mb_skipped=1;

                if(s->mb_skipped==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 */
            cbpc = cbp & 3;
            cbpy = cbp >> 2;
            cbpy ^= 0xf;
            if(s->mv_type==MV_TYPE_16X16){
                if(s->dquant) cbpc+= 8;
                put_bits(&s->pb,
                        inter_MCBPC_bits[cbpc],
                        inter_MCBPC_code[cbpc]);

                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);
                }

                if(interleaved_stats){
                    s->misc_bits+= get_bits_diff(s);
                }

                /* motion vectors: 16x16 mode */
                h263_pred_motion(s, 0, 0, &pred_x, &pred_y);

                ff_h263_encode_motion_vector(s, motion_x - pred_x,
                                                motion_y - pred_y, s->f_code);
            }else if(s->mv_type==MV_TYPE_FIELD){
                if(s->dquant) cbpc+= 8;
                put_bits(&s->pb,
                        inter_MCBPC_bits[cbpc],
                        inter_MCBPC_code[cbpc]);

                put_bits(pb2, cbpy_tab[cbpy][1], cbpy_tab[cbpy][0]);