macroblock_enc.c

H.264改进解码软件

/*****************************************************************************
 * macroblock.c: h264 encoder library
 *****************************************************************************
 * Copyright (C) 2003 Laurent Aimar
 * $Id: macroblock.c,v 1.1 2004/06/03 19:27:08 fenrir Exp $
 *
 * Authors: Laurent Aimar <[e-mail]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
 *****************************************************************************/

#include <stdio.h>
#include <string.h>

#include "common.h"
#include "macroblock_enc.h"


/* def_quant4_mf only for probe_skip; actual encoding uses matrices from set.c */
/* FIXME this seems to make better decisions with cqm=jvt, but could screw up
 * with general custom matrices. */
static const int def_quant4_mf[6][4][4] =
{
    { { 13107, 8066, 13107, 8066 }, { 8066, 5243, 8066, 5243 },
      { 13107, 8066, 13107, 8066 }, { 8066, 5243, 8066, 5243 } },
    { { 11916, 7490, 11916, 7490 }, { 7490, 4660, 7490, 4660 },
      { 11916, 7490, 11916, 7490 }, { 7490, 4660, 7490, 4660 } },
    { { 10082, 6554, 10082, 6554 }, { 6554, 4194, 6554, 4194 },
      { 10082, 6554, 10082, 6554 }, { 6554, 4194, 6554, 4194 } },
    { {  9362, 5825,  9362, 5825 }, { 5825, 3647, 5825, 3647 },
      {  9362, 5825,  9362, 5825 }, { 5825, 3647, 5825, 3647 } },
    { {  8192, 5243,  8192, 5243 }, { 5243, 3355, 5243, 3355 },
      {  8192, 5243,  8192, 5243 }, { 5243, 3355, 5243, 3355 } },
    { {  7282, 4559,  7282, 4559 }, { 4559, 2893, 4559, 2893 },
      {  7282, 4559,  7282, 4559 }, { 4559, 2893, 4559, 2893 } }
};

/****************************************************************************
 * Scan and Quant functions
 ****************************************************************************/
//static const int scan_zigzag_x[16]={0, 1, 0, 0, 1, 2, 3, 2, 1, 0, 1, 2, 3, 3, 2, 3};
//static const int scan_zigzag_y[16]={0, 0, 1, 2, 1, 0, 0, 1, 2, 3, 3, 2, 1, 2, 3, 3};

#define ZIG(i,y,x) level[i] = dct[y][x];//用宏定义赋值语句,用到两个值参
static void scan_zigzag_8x8full( int level[64], int16_t dct[8][8] )
{
    ZIG( 0,0,0) ZIG( 1,0,1) ZIG( 2,1,0) ZIG( 3,2,0)
    ZIG( 4,1,1) ZIG( 5,0,2) ZIG( 6,0,3) ZIG( 7,1,2)
    ZIG( 8,2,1) ZIG( 9,3,0) ZIG(10,4,0) ZIG(11,3,1)
    ZIG(12,2,2) ZIG(13,1,3) ZIG(14,0,4) ZIG(15,0,5)
    ZIG(16,1,4) ZIG(17,2,3) ZIG(18,3,2) ZIG(19,4,1)
    ZIG(20,5,0) ZIG(21,6,0) ZIG(22,5,1) ZIG(23,4,2)
    ZIG(24,3,3) ZIG(25,2,4) ZIG(26,1,5) ZIG(27,0,6)
    ZIG(28,0,7) ZIG(29,1,6) ZIG(30,2,5) ZIG(31,3,4)
    ZIG(32,4,3) ZIG(33,5,2) ZIG(34,6,1) ZIG(35,7,0)
    ZIG(36,7,1) ZIG(37,6,2) ZIG(38,5,3) ZIG(39,4,4)
    ZIG(40,3,5) ZIG(41,2,6) ZIG(42,1,7) ZIG(43,2,7)
    ZIG(44,3,6) ZIG(45,4,5) ZIG(46,5,4) ZIG(47,6,3)
    ZIG(48,7,2) ZIG(49,7,3) ZIG(50,6,4) ZIG(51,5,5)
    ZIG(52,4,6) ZIG(53,3,7) ZIG(54,4,7) ZIG(55,5,6)
    ZIG(56,6,5) ZIG(57,7,4) ZIG(58,7,5) ZIG(59,6,6)
    ZIG(60,5,7) ZIG(61,6,7) ZIG(62,7,6) ZIG(63,7,7)
}
static void scan_zigzag_4x4full( int level[16], int16_t dct[4][4] )
{
    ZIG( 0,0,0) ZIG( 1,0,1) ZIG( 2,1,0) ZIG( 3,2,0)
    ZIG( 4,1,1) ZIG( 5,0,2) ZIG( 6,0,3) ZIG( 7,1,2)
    ZIG( 8,2,1) ZIG( 9,3,0) ZIG(10,3,1) ZIG(11,2,2)
    ZIG(12,1,3) ZIG(13,2,3) ZIG(14,3,2) ZIG(15,3,3)
}
static void scan_zigzag_4x4( int level[15], int16_t dct[4][4] )
{
                ZIG( 0,0,1) ZIG( 1,1,0) ZIG( 2,2,0)
    ZIG( 3,1,1) ZIG( 4,0,2) ZIG( 5,0,3) ZIG( 6,1,2)
    ZIG( 7,2,1) ZIG( 8,3,0) ZIG( 9,3,1) ZIG(10,2,2)
    ZIG(11,1,3) ZIG(12,2,3) ZIG(13,3,2) ZIG(14,3,3)
}
static void scan_zigzag_2x2_dc( int level[4], int16_t dct[2][2] )
{
    ZIG(0,0,0)
    ZIG(1,0,1)
    ZIG(2,1,0)
    ZIG(3,1,1)
}
#undef ZIG

#define ZIG(i,y,x) {\
    int oe = x+y*FENC_STRIDE;\
    int od = x+y*FDEC_STRIDE;\
    level[i] = p_src[oe] - p_dst[od];\
    p_dst[od] = p_src[oe];\
}
static void sub_zigzag_4x4full( int level[16], const uint8_t *p_src, uint8_t *p_dst )
{
    ZIG( 0,0,0) ZIG( 1,0,1) ZIG( 2,1,0) ZIG( 3,2,0)
    ZIG( 4,1,1) ZIG( 5,0,2) ZIG( 6,0,3) ZIG( 7,1,2)
    ZIG( 8,2,1) ZIG( 9,3,0) ZIG(10,3,1) ZIG(11,2,2)
    ZIG(12,1,3) ZIG(13,2,3) ZIG(14,3,2) ZIG(15,3,3)
}
static void sub_zigzag_4x4( int level[15], const uint8_t *p_src, uint8_t *p_dst )
{
                ZIG( 0,0,1) ZIG( 1,1,0) ZIG( 2,2,0)
    ZIG( 3,1,1) ZIG( 4,0,2) ZIG( 5,0,3) ZIG( 6,1,2)
    ZIG( 7,2,1) ZIG( 8,3,0) ZIG( 9,3,1) ZIG(10,2,2)
    ZIG(11,1,3) ZIG(12,2,3) ZIG(13,3,2) ZIG(14,3,3)
}
#undef ZIG

static void quant_8x8( x264_t *h, int16_t dct[8][8], int quant_mf[6][8][8], int i_qscale, int b_intra )
{
    const int i_qbits = 16 + i_qscale / 6;
    const int i_mf = i_qscale % 6;
    const int f = ( 1 << i_qbits ) / ( b_intra ? 3 : 6 );
    h->quantf.quant_8x8_core( dct, quant_mf[i_mf], i_qbits, f );
}
static void quant_4x4( x264_t *h, int16_t dct[4][4], int quant_mf[6][4][4], int i_qscale, int b_intra )
{
    const int i_qbits = 15 + i_qscale / 6;
    const int i_mf = i_qscale % 6;
    const int f = ( 1 << i_qbits ) / ( b_intra ? 3 : 6 );
    h->quantf.quant_4x4_core( dct, quant_mf[i_mf], i_qbits, f );
}
static void quant_4x4_dc( x264_t *h, int16_t dct[4][4], int quant_mf[6][4][4], int i_qscale )
{
    const int i_qbits = 16 + i_qscale / 6;
    const int i_mf = i_qscale % 6;
    const int f = ( 1 << i_qbits ) / 3;
    h->quantf.quant_4x4_dc_core( dct, quant_mf[i_mf][0][0], i_qbits, f );
}
static void quant_2x2_dc( x264_t *h, int16_t dct[2][2], int quant_mf[6][4][4], int i_qscale, int b_intra )
{
    const int i_qbits = 16 + i_qscale / 6;
    const int i_mf = i_qscale % 6;
    const int f = ( 1 << i_qbits ) / ( b_intra ? 3 : 6 );
    h->quantf.quant_2x2_dc_core( dct, quant_mf[i_mf][0][0], i_qbits, f );
}

/* (ref: JVT-B118)
 * x264_mb_decimate_score: given dct coeffs it returns a score to see if we could empty this dct coeffs
 * to 0 (low score means set it to null)
 * Used in inter macroblock (luma and chroma)
 *  luma: for a 8x8 block: if score < 4 -> null
 *        for the complete mb: if score < 6 -> null
 *  chroma: for the complete mb: if score < 7 -> null
 */
static int x264_mb_decimate_score( int *dct, int i_max )
{
    static const int i_ds_table4[16] = {
        3,2,2,1,1,1,0,0,0,0,0,0,0,0,0,0 };
    static const int i_ds_table8[64] = {
        3,3,3,3,2,2,2,2,2,2,2,2,1,1,1,1,
        1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,
        0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
        0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 };

    const int *ds_table = (i_max == 64) ? i_ds_table8 : i_ds_table4;
    int i_score = 0;
    int idx = i_max - 1;

    while( idx >= 0 && dct[idx] == 0 )
        idx--;

    while( idx >= 0 )
    {
        int i_run;

        if( abs( dct[idx--] ) > 1 )
            return 9;

        i_run = 0;
        while( idx >= 0 && dct[idx] == 0 )
        {
            idx--;
            i_run++;
        }
        i_score += ds_table[i_run];
    }

    return i_score;
}

void x264_mb_encode_i4x4( x264_t *h, int idx, int i_qscale )
{
    int x = 4 * block_idx_x[idx];//当前4*4块首像素在宏块内的坐标
    int y = 4 * block_idx_y[idx];
    uint8_t *p_src = &h->mb.pic.p_fenc[0][x+y*FENC_STRIDE];//真实值
    uint8_t *p_dst = &h->mb.pic.p_fdec[0][x+y*FDEC_STRIDE];//预测值
    int16_t dct4x4[4][4];

    if( h->mb.b_lossless )
    {
        sub_zigzag_4x4full( h->dct.block[idx].luma4x4, p_src, p_dst );
        return;
    }

    h->dctf.sub4x4_dct( dct4x4, p_src, FENC_STRIDE, p_dst, FDEC_STRIDE );//对亮度预测差值做dct变换-->dct4x4

//    if( h->mb.b_trellis )
//        x264_quant_4x4_trellis( h, dct4x4, CQM_4IY, i_qscale, DCT_LUMA_4x4, 1 );
//    else
        quant_4x4( h, dct4x4, h->quant4_mf[CQM_4IY], i_qscale, 1 );//量化,量化后系数-->dct4x4

    scan_zigzag_4x4full( h->dct.block[idx].luma4x4, dct4x4 );//将量化系数之字形扫描放到一维数组函数h->dct.block[idx].luma4x4[]
    h->quantf.dequant_4x4( dct4x4, h->dequant4_mf[CQM_4IY], i_qscale );//反量化系数-->h->dequant4_mf[CQM_4IY]

    /* output samples to fdec */
    h->dctf.add4x4_idct( p_dst, FDEC_STRIDE, dct4x4 );//差值反dct变换,然后加上预测值得到重构宏块数据-->h->mb....fdec[]
}

void x264_mb_encode_i8x8( x264_t *h, int idx, int i_qscale )
{
    int x = 8 * (idx&1);
    int y = 8 * (idx>>1);
    uint8_t *p_src = &h->mb.pic.p_fenc[0][x+y*FENC_STRIDE];
    uint8_t *p_dst = &h->mb.pic.p_fdec[0][x+y*FDEC_STRIDE];
    int16_t dct8x8[8][8];

    h->dctf.sub8x8_dct8( dct8x8, p_src, FENC_STRIDE, p_dst, FDEC_STRIDE );

//    if( h->mb.b_trellis )
//        x264_quant_8x8_trellis( h, dct8x8, CQM_8IY, i_qscale, 1 );
//    else 
        quant_8x8( h, dct8x8, h->quant8_mf[CQM_8IY], i_qscale, 1 );

    scan_zigzag_8x8full( h->dct.luma8x8[idx], dct8x8 );
    h->quantf.dequant_8x8( dct8x8, h->dequant8_mf[CQM_8IY], i_qscale );
    h->dctf.add8x8_idct8( p_dst, FDEC_STRIDE, dct8x8 );
}

static void x264_mb_encode_i16x16( x264_t *h, int i_qscale )
{
    uint8_t  *p_src = h->mb.pic.p_fenc[0];
    uint8_t  *p_dst = h->mb.pic.p_fdec[0];

    int16_t dct4x4[16+1][4][4];

    int i;

    if( h->mb.b_lossless )
    {
        for( i = 0; i < 16; i++ )
        {
            int oe = block_idx_x[i]*4 + block_idx_y[i]*4*FENC_STRIDE;
            int od = block_idx_x[i]*4 + block_idx_y[i]*4*FDEC_STRIDE;
            sub_zigzag_4x4( h->dct.block[i].residual_ac, p_src+oe, p_dst+od );
            dct4x4[0][block_idx_y[i]][block_idx_x[i]] = p_src[oe] - p_dst[od];
            p_dst[od] = p_src[oe];
        }
        scan_zigzag_4x4full( h->dct.luma16x16_dc, dct4x4[0] );
        return;
    }

    h->dctf.sub16x16_dct( &dct4x4[1], p_src, FENC_STRIDE, p_dst, FDEC_STRIDE );
    for( i = 0; i < 16; i++ )
    {
        /* copy dc coeff */
        dct4x4[0][block_idx_y[i]][block_idx_x[i]] = dct4x4[1+i][0][0];

        /* quant/scan/dequant */
//        if( h->mb.b_trellis )
//            x264_quant_4x4_trellis( h, dct4x4[1+i], CQM_4IY, i_qscale, DCT_LUMA_AC, 1 );
//        else
            quant_4x4( h, dct4x4[1+i], h->quant4_mf[CQM_4IY], i_qscale, 1 );

        scan_zigzag_4x4( h->dct.block[i].residual_ac, dct4x4[1+i] );
        h->quantf.dequant_4x4( dct4x4[1+i], h->dequant4_mf[CQM_4IY], i_qscale );
    }

    h->dctf.dct4x4dc( dct4x4[0] );
    quant_4x4_dc( h, dct4x4[0], h->quant4_mf[CQM_4IY], i_qscale );
    scan_zigzag_4x4full( h->dct.luma16x16_dc, dct4x4[0] );

    /* output samples to fdec */
    h->dctf.idct4x4dc( dct4x4[0] );
    x264_mb_dequant_4x4_dc( dct4x4[0], h->dequant4_mf[CQM_4IY], i_qscale );  /* XXX not inversed */

    /* calculate dct coeffs */
    for( i = 0; i < 16; i++ )
    {
        /* copy dc coeff */
        dct4x4[1+i][0][0] = dct4x4[0][block_idx_y[i]][block_idx_x[i]];
    }
    /* put pixels to fdec */
    h->dctf.add16x16_idct( p_dst, FDEC_STRIDE, &dct4x4[1] );
}

static void x264_mb_encode_8x8_chroma( x264_t *h, int b_inter, int i_qscale )
{
    int i, ch;

    for( ch = 0; ch < 2; ch++ )
    {
        uint8_t  *p_src = h->mb.pic.p_fenc[1+ch];
        uint8_t  *p_dst = h->mb.pic.p_fdec[1+ch];
        int i_decimate_score = 0;

        int16_t dct2x2[2][2];
        int16_t dct4x4[4][4][4];

        if( h->mb.b_lossless )
        {
            for( i = 0; i < 4; i++ )
            {
                int oe = block_idx_x[i]*4 + block_idx_y[i]*4*FENC_STRIDE;
                int od = block_idx_x[i]*4 + block_idx_y[i]*4*FDEC_STRIDE;
                sub_zigzag_4x4( h->dct.block[16+i+ch*4].residual_ac, p_src+oe, p_dst+od );
                h->dct.chroma_dc[ch][i] = p_src[oe] - p_dst[od];
                p_dst[od] = p_src[oe];
            }
            continue;
        }
            
        h->dctf.sub8x8_dct( dct4x4, p_src, FENC_STRIDE, p_dst, FDEC_STRIDE );
        /* calculate dct coeffs */
        for( i = 0; i < 4; i++ )
        {
            /* copy dc coeff */
            dct2x2[block_idx_y[i]][block_idx_x[i]] = dct4x4[i][0][0];

            /* no trellis; it doesn't seem to help chroma noticeably */
            quant_4x4( h, dct4x4[i], h->quant4_mf[CQM_4IC + b_inter], i_qscale, !b_inter );
            scan_zigzag_4x4( h->dct.block[16+i+ch*4].residual_ac, dct4x4[i] );

            if( b_inter )
            {
                i_decimate_score += x264_mb_decimate_score( h->dct.block[16+i+ch*4].residual_ac, 15 );
            }
        }

        h->dctf.dct2x2dc( dct2x2 );
        quant_2x2_dc( h, dct2x2, h->quant4_mf[CQM_4IC + b_inter], i_qscale, !b_inter );
        scan_zigzag_2x2_dc( h->dct.chroma_dc[ch], dct2x2 );

        /* output samples to fdec */
        h->dctf.idct2x2dc( dct2x2 );
        x264_mb_dequant_2x2_dc( dct2x2, h->dequant4_mf[CQM_4IC + b_inter], i_qscale );  /* XXX not inversed */

        if( b_inter && i_decimate_score < 7 )
        {
            /* Near null chroma 8x8 block so make it null (bits saving) */
            memset( dct4x4, 0, sizeof( dct4x4 ) );
            memset( &h->dct.block[16+ch*4], 0, 4 * sizeof( *h->dct.block ) );
        }
        else
        {
            for( i = 0; i < 4; i++ )
                h->quantf.dequant_4x4( dct4x4[i], h->dequant4_mf[CQM_4IC + b_inter], i_qscale );
        }

        /* calculate dct coeffs */
        for( i = 0; i < 4; i++ )
        {
            /* copy dc coeff */
            dct4x4[i][0][0] = dct2x2[0][i];
        }
        h->dctf.add8x8_idct( p_dst, FDEC_STRIDE, dct4x4 );
    }
}

static void x264_macroblock_encode_skip( x264_t *h )
{
    int i;
    h->mb.i_cbp_luma = 0x00;
    h->mb.i_cbp_chroma = 0x00;

    for( i = 0; i < 16+8; i++ )
    {
        h->mb.cache.non_zero_count[x264_scan8[i]] = 0;
    }

    /* store cbp */
    h->mb.cbp[h->mb.i_mb_xy] = 0;
}

/*****************************************************************************
 * x264_macroblock_encode_pskip:
 *  Encode an already marked skip block
 *****************************************************************************/
void x264_macroblock_encode_pskip( x264_t *h )
{
    const int mvx = x264_clip3( h->mb.cache.mv[0][x264_scan8[0]][0],
                                h->mb.mv_min[0], h->mb.mv_max[0] );
    const int mvy = x264_clip3( h->mb.cache.mv[0][x264_scan8[0]][1],
                                h->mb.mv_min[1], h->mb.mv_max[1] );

    /* Motion compensation XXX probably unneeded */
    h->mc.mc_luma( h->mb.pic.p_fref[0][0], h->mb.pic.i_stride[0],
                   h->mb.pic.p_fdec[0],    FDEC_STRIDE,
                   mvx, mvy, 16, 16 );

    /* Chroma MC */
    h->mc.mc_chroma( h->mb.pic.p_fref[0][0][4], h->mb.pic.i_stride[1],
                     h->mb.pic.p_fdec[1],       FDEC_STRIDE,
                     mvx, mvy, 8, 8 );

    h->mc.mc_chroma( h->mb.pic.p_fref[0][0][5], h->mb.pic.i_stride[2],
                     h->mb.pic.p_fdec[2],       FDEC_STRIDE,
                     mvx, mvy, 8, 8 );

    x264_macroblock_encode_skip( h );
}

/*****************************************************************************
 * x264_macroblock_encode:
 *****************************************************************************/
void x264_macroblock_encode( x264_t *h )
{
    int i_cbp_dc = 0;
    int i_qp = h->mb.i_qp;
    int i;

    if( h->mb.i_type == P_SKIP )
    {
        /* A bit special */
        x264_macroblock_encode_pskip( h );