macroblock.c

H.264编码器

    }

    /* Write:
      - type
      - prediction
      - mv */
    if( mb->i_type == I_PCM )
    {
        /* Untested */
        bs_write_ue( s, i_mb_i_offset + 25 );

        bs_align_0( s );
        /* Luma */
        for( i = 0; i < 16*16; i++ )
        {
            bs_write( s, 8, h->picture->plane[0][mb->i_mb_y * 16 * h->picture->i_stride[0] + mb->i_mb_x * 16+i] );
        }
        /* Cb */
        for( i = 0; i < 8*8; i++ )
        {
            bs_write( s, 8, h->picture->plane[1][mb->i_mb_y * 8 * h->picture->i_stride[1] + mb->i_mb_x * 8+i] );
        }
        /* Cr */
        for( i = 0; i < 8*8; i++ )
        {
            bs_write( s, 8, h->picture->plane[2][mb->i_mb_y * 8 * h->picture->i_stride[2] + mb->i_mb_x * 8+i] );
        }

        for( i = 0; i < 16 + 8; i++ )
        {
            /* special case */
            mb->block[i].i_non_zero_count = 16;
        }
        return;
    }
    else if( mb->i_type == I_4x4 )
    {
        bs_write_ue( s, i_mb_i_offset + 0 );

        /* Prediction: Luma */
        for( i = 0; i < 16; i++ )
        {
            int i_predicted_mode = x264_mb_predict_intra4x4_mode( h, mb, i );
            int i_mode = mb->block[i].i_intra4x4_pred_mode;

            if( i_predicted_mode == i_mode)
            {
                bs_write1( s, 1 );  /* b_prev_intra4x4_pred_mode */
            }
            else
            {
                bs_write1( s, 0 );  /* b_prev_intra4x4_pred_mode */
                if( i_mode < i_predicted_mode )
                {
                    bs_write( s, 3, i_mode );
                }
                else
                {
                    bs_write( s, 3, i_mode - 1 );
                }
            }
        }
        /* Prediction: chroma */
        bs_write_ue( s, mb->i_chroma_pred_mode );
    }
    else if( mb->i_type == I_16x16 )
    {
        bs_write_ue( s, i_mb_i_offset + 1 + mb->i_intra16x16_pred_mode +
                                            mb->i_cbp_chroma * 4 +
                                            ( mb->i_cbp_luma == 0 ? 0 : 12 ) );
        /* Prediction: chroma */
        bs_write_ue( s, mb->i_chroma_pred_mode );
    }
    else if( mb->i_type == P_L0 )
    {
        int mvp[2];

        if( mb->i_partition == D_16x16 )
        {
            bs_write_ue( s, 0 );

            if( h->sh.i_num_ref_idx_l0_active > 1 )
            {
                bs_write_te( s, h->sh.i_num_ref_idx_l0_active - 1, mb->partition[0][0].i_ref[0] );
            }
            x264_mb_predict_mv( mb, 0, 0, 0, mvp );
            bs_write_se( s, mb->partition[0][0].mv[0][0] - mvp[0] );
            bs_write_se( s, mb->partition[0][0].mv[0][1] - mvp[1] );
        }
        else if( mb->i_partition == D_16x8 )
        {
            bs_write_ue( s, 1 );
            if( h->sh.i_num_ref_idx_l0_active > 1 )
            {
                bs_write_te( s, h->sh.i_num_ref_idx_l0_active - 1, mb->partition[0][0].i_ref[0] );
                bs_write_te( s, h->sh.i_num_ref_idx_l0_active - 1, mb->partition[0][2].i_ref[0] );
            }

            x264_mb_predict_mv( mb, 0, 0, 0, mvp );
            bs_write_se( s, mb->partition[0][0].mv[0][0] - mvp[0] );
            bs_write_se( s, mb->partition[0][0].mv[0][1] - mvp[1] );

            x264_mb_predict_mv( mb, 0, 1, 0, mvp );
            bs_write_se( s, mb->partition[0][2].mv[0][0] - mvp[0] );
            bs_write_se( s, mb->partition[0][2].mv[0][1] - mvp[1] );
        }
        else if( mb->i_partition == D_8x16 )
        {
            bs_write_ue( s, 2 );
            if( h->sh.i_num_ref_idx_l0_active > 1 )
            {
                bs_write_te( s, h->sh.i_num_ref_idx_l0_active - 1, mb->partition[0][0].i_ref[0] );
                bs_write_te( s, h->sh.i_num_ref_idx_l0_active - 1, mb->partition[2][0].i_ref[0] );
            }

            x264_mb_predict_mv( mb, 0, 0, 0, mvp );
            bs_write_se( s, mb->partition[0][0].mv[0][0] - mvp[0] );
            bs_write_se( s, mb->partition[0][0].mv[0][1] - mvp[1] );

            x264_mb_predict_mv( mb, 0, 1, 0, mvp );
            bs_write_se( s, mb->partition[2][0].mv[0][0] - mvp[0] );
            bs_write_se( s, mb->partition[2][0].mv[0][1] - mvp[1] );
        }
    }
    else if( mb->i_type == P_8x8 )
    {
        int b_sub_ref0;

        if( mb->partition[0][0].i_ref[0] == 0 &&
            mb->partition[0][2].i_ref[0] == 0 &&
            mb->partition[2][0].i_ref[0] == 0 &&
            mb->partition[2][2].i_ref[0] == 0 )
        {
            bs_write_ue( s, 4 );
            b_sub_ref0 = 0;
        }
        else
        {
            bs_write_ue( s, 3 );
            b_sub_ref0 = 1;
        }
        /* sub mb type */
        for( i = 0; i < 4; i++ )
        {
            switch( mb->i_sub_partition[i] )
            {
                case D_L0_8x8:
                    bs_write_ue( s, 0 );
                    break;
                case D_L0_8x4:
                    bs_write_ue( s, 1 );
                    break;
                case D_L0_4x8:
                    bs_write_ue( s, 2 );
                    break;
                case D_L0_4x4:
                    bs_write_ue( s, 3 );
                    break;
            }
        }
        /* ref0 */
        if( h->sh.i_num_ref_idx_l0_active > 1 && b_sub_ref0 )
        {
            bs_write_te( s, h->sh.i_num_ref_idx_l0_active - 1, mb->partition[0][0].i_ref[0] );
            bs_write_te( s, h->sh.i_num_ref_idx_l0_active - 1, mb->partition[2][0].i_ref[0] );
            bs_write_te( s, h->sh.i_num_ref_idx_l0_active - 1, mb->partition[0][2].i_ref[0] );
            bs_write_te( s, h->sh.i_num_ref_idx_l0_active - 1, mb->partition[2][2].i_ref[0] );
        }
        for( i = 0; i < 4; i++ )
        {
            int i_part;
            for( i_part = 0; i_part < x264_mb_partition_count_table[mb->i_sub_partition[i]]; i_part++ )
            {
                int mvx, mvy;
                int mvp[2];

                x264_mb_partition_get( mb, 0, i, i_part, NULL, &mvx, &mvy );
                x264_mb_predict_mv( mb, 0, i, i_part, mvp );

                bs_write_se( s, mvx - mvp[0] );
                bs_write_se( s, mvy - mvp[1]);
            }
        }
    }
    else if( mb->i_type == B_8x8 )
    {
        fprintf( stderr, "invalid/unhandled mb_type (B_8x8)\n" );
        return;
    }
    else if( mb->i_type != B_DIRECT )
    {
        /* All B mode */
        /* Motion Vector */
        int i_part = x264_mb_partition_count_table[mb->i_partition];
        int i_ref;
        int mvx, mvy;
        int mvp[2];

        int b_list0[2];
        int b_list1[2];

        /* init ref list utilisations */
        for( i = 0; i < 2; i++ )
        {
            b_list0[i] = x264_mb_type_list0_table[mb->i_type][i];
            b_list1[i] = x264_mb_type_list1_table[mb->i_type][i];
        }


        if( mb->i_partition == D_16x16 )
        {
            if( b_list0[0] && b_list1[0] )
            {
                bs_write_ue( s, 3 );
            }
            else if( b_list1[0] )
            {
                bs_write_ue( s, 2 );
            }
            else
            {
                bs_write_ue( s, 1 );
            }
        }
        else
        {
            if( mb->i_type == B_BI_BI )
            {
                bs_write_ue( s, 20 + (mb->i_partition == D_16x8 ? 0 : 1 ) );
            }
            else if( b_list0[0] && b_list1[0] )
            {
                /* B_BI_LX* */
                bs_write_ue( s, 16 + (b_list0[1]?0:2) + (mb->i_partition == D_16x8?0:1) );
            }
            else if( b_list0[1] && b_list1[1] )
            {
                /* B_LX_BI */
                bs_write_ue( s, 12 + (b_list0[1]?0:2) + (mb->i_partition == D_16x8?0:1) );
            }
            else if( b_list1[1] )
            {
                /* B_LX_L1 */
                bs_write_ue( s, 6 + (b_list0[0]?2:0) + (mb->i_partition == D_16x8?0:1) );
            }
            else if( b_list0[1] )
            {
                /* B_LX_L0 */
                bs_write_ue( s, 4 + (b_list0[0]?0:6) + (mb->i_partition == D_16x8?0:1) );
            }
        }

        if( h->sh.i_num_ref_idx_l0_active > 1 )
        {
            for( i = 0; i < i_part; i++ )
            {
                if( b_list0[i] )
                {
                    x264_mb_partition_get( mb, 0, i, 0, &i_ref, NULL, NULL );
                    bs_write_te( s, h->sh.i_num_ref_idx_l0_active - 1, i_ref );
                }
            }
        }
        if( h->sh.i_num_ref_idx_l1_active > 1 )
        {
            for( i = 0; i < i_part; i++ )
            {
                if( b_list1[i] )
                {
                    x264_mb_partition_get( mb, 1, i, 0, &i_ref, NULL, NULL );
                    bs_write_te( s, h->sh.i_num_ref_idx_l1_active - 1, i_ref );
                }
            }
        }

        for( i = 0; i < i_part; i++ )
        {
            if( b_list0[i] )
            {
                x264_mb_partition_get( mb, 0, i, 0, NULL, &mvx, &mvy );
                x264_mb_predict_mv( mb, 0, i, 0, mvp );

                bs_write_se( s, mvx - mvp[0] );
                bs_write_se( s, mvy - mvp[1] );
            }
        }
        for( i = 0; i < i_part; i++ )
        {
            if( b_list1[i] )
            {
                x264_mb_partition_get( mb, 1, i, 0, NULL, &mvx, &mvy );
                x264_mb_predict_mv( mb, 1, i, 0, mvp );

                bs_write_se( s, mvx - mvp[0] );
                bs_write_se( s, mvy - mvp[1] );
            }
        }
    }
    else if( mb->i_type == B_DIRECT )
    {
        bs_write_ue( s, 0 );
    }
    else
    {
        fprintf( stderr, "invalid/unhandled mb_type\n" );
        return;
    }

    /* Coded block patern */
    if( mb->i_type == I_4x4 )
    {
        bs_write_ue( s, intra4x4_cbp_to_golomb[( mb->i_cbp_chroma << 4 )|mb->i_cbp_luma] );
    }
    else if( mb->i_type != I_16x16 )
    {
        bs_write_ue( s, inter_cbp_to_golomb[( mb->i_cbp_chroma << 4 )|mb->i_cbp_luma] );
    }

    /* write residual */
    if( mb->i_type == I_16x16 )
    {
        if( mb->i_mb_x > 0 || mb->i_mb_y > 0 )
            bs_write_se( s, mb->i_qp - (mb-1)->i_qp);
        else
            bs_write_se( s, mb->i_qp - h->pps->i_pic_init_qp - h->sh.i_qp_delta );

        /* DC Luma */
        block_residual_write_cavlc( h, s, mb, BLOCK_INDEX_LUMA_DC , mb->luma16x16_dc, 16 );

        if( mb->i_cbp_luma != 0 )
        {
            /* AC Luma */
            for( i = 0; i < 16; i++ )
            {
                block_residual_write_cavlc( h, s, mb, i, mb->block[i].residual_ac, 15 );
            }
        }
    }
    else if( mb->i_cbp_luma != 0 || mb->i_cbp_chroma != 0 )
    {
        bs_write_se( s, mb->i_qp - h->pps->i_pic_init_qp - h->sh.i_qp_delta );

        for( i = 0; i < 16; i++ )
        {
            if( mb->i_cbp_luma & ( 1 << ( i / 4 ) ) )
            {
                block_residual_write_cavlc( h, s, mb, i, mb->block[i].luma4x4, 16 );
            }
        }
    }
    if( mb->i_cbp_chroma != 0 )
    {
        /* Chroma DC residual present */
        block_residual_write_cavlc( h, s, mb, BLOCK_INDEX_CHROMA_DC, mb->chroma_dc[0], 4 );
        block_residual_write_cavlc( h, s, mb, BLOCK_INDEX_CHROMA_DC, mb->chroma_dc[1], 4 );
        if( mb->i_cbp_chroma&0x02 ) /* Chroma AC residual present */
        {
            for( i = 0; i < 8; i++ )
            {
                block_residual_write_cavlc( h, s, mb, 16 + i, mb->block[16+i].residual_ac, 15 );
            }
        }
    }
}

/*****************************************************************************
 *
 * Cabac stuff
 *
 *****************************************************************************/

static void x264_cabac_mb_type( x264_t *h, x264_macroblock_t *mb )
{
    x264_macroblock_t *mba = mb->context->mba;
    x264_macroblock_t *mbb = mb->context->mbb;
    int i_ctxIdxInc    = 0;

    if( h->sh.i_type == SLICE_TYPE_I )
    {

        if( mba != NULL && mba->i_type != I_4x4 )
        {
            i_ctxIdxInc++;
        }
        if( mbb != NULL && mbb->i_type != I_4x4 )
        {
            i_ctxIdxInc++;
        }

        if( mb->i_type == I_4x4 )
        {
            x264_cabac_encode_decision( &h->cabac, 3 + i_ctxIdxInc, 0 );
        }
        else if( mb->i_type == I_PCM )
        {
            x264_cabac_encode_decision( &h->cabac, 3 + i_ctxIdxInc, 1 );
            x264_cabac_encode_terminal( &h->cabac, 1 ); /*ctxIdx == 276 */
        }
        else    /* I_16x16 */
        {
            x264_cabac_encode_decision( &h->cabac, 3 + i_ctxIdxInc, 1 );
            x264_cabac_encode_terminal( &h->cabac, 0 ); /*ctxIdx == 276 */

            x264_cabac_encode_decision( &h->cabac, 3 + 3, ( mb->i_cbp_luma == 0 ? 0 : 1 ));
            if( mb->i_cbp_chroma == 0 )
            {
                x264_cabac_encode_decision( &h->cabac, 3 + 4, 0 );
            }
            else
            {
                x264_cabac_encode_decision( &h->cabac, 3 + 4, 1 );
                x264_cabac_encode_decision( &h->cabac, 3 + 5, ( mb->i_cbp_chroma == 1 ? 0 : 1 ) );
            }
            x264_cabac_encode_decision( &h->cabac, 3 + 6, ( (mb->i_intra16x16_pred_mode / 2) ? 1 : 0 ));
            x264_cabac_encode_decision( &h->cabac, 3 + 7, ( (mb->i_intra16x16_pred_mode % 2) ? 1 : 0 ));
        }
    }
    else if( h->sh.i_type == SLICE_TYPE_P )
    {
        /* prefix: 14, suffix: 17 */
        if( mb->i_type == P_L0 )
        {
            if( mb->i_partition == D_16x16 )
            {
                x264_cabac_encode_decision( &h->cabac, 14, 0 );
                x264_cabac_encode_decision( &h->cabac, 15, 0 );
                x264_cabac_encode_decision( &h->cabac, 16, 0 );
            }
            else if( mb->i_partition == D_16x8 )
            {
                x264_cabac_encode_decision( &h->cabac, 14, 0 );
                x264_cabac_encode_decision( &h->cabac, 15, 1 );
                x264_cabac_encode_decision( &h->cabac, 17, 1 );
            }
            else if( mb->i_partition == D_8x16 )
            {
                x264_cabac_encode_decision( &h->cabac, 14, 0 );