intrax8.c

ffmpeg移植到symbian的全部源代码

/*
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file intrax8.c
 * @brief IntraX8 (J-Frame) subdecoder, used by WMV2 and VC-1
 */

#include "avcodec.h"
#include "bitstream.h"
#include "mpegvideo.h"
#include "msmpeg4data.h"
#include "intrax8huf.h"
#include "intrax8.h"

#define MAX_TABLE_DEPTH(table_bits, max_bits) ((max_bits+table_bits-1)/table_bits)

#define DC_VLC_BITS 9
#define AC_VLC_BITS 9
#define OR_VLC_BITS 7

#define DC_VLC_MTD MAX_TABLE_DEPTH(DC_VLC_BITS, MAX_DC_VLC_BITS)
#define AC_VLC_MTD MAX_TABLE_DEPTH(AC_VLC_BITS, MAX_AC_VLC_BITS)
#define OR_VLC_MTD MAX_TABLE_DEPTH(OR_VLC_BITS, MAX_OR_VLC_BITS)

static VLC j_ac_vlc[2][2][8];  //[quant<13],[intra/inter],[select]
static VLC j_dc_vlc[2][8];     //[quant], [select]
static VLC j_orient_vlc[2][4]; //[quant], [select]

static void x8_vlc_init(){
    int i;

#define  init_ac_vlc(dst,src) \
       init_vlc(&dst, \
              AC_VLC_BITS,77, \
              &src[1],4,2, \
              &src[0],4,2, \
              1)
//set ac tables
    for(i=0;i<8;i++){
        init_ac_vlc( j_ac_vlc[0][0][i], x8_ac0_highquant_table[i][0] );
        init_ac_vlc( j_ac_vlc[0][1][i], x8_ac1_highquant_table[i][0] );
        init_ac_vlc( j_ac_vlc[1][0][i], x8_ac0_lowquant_table [i][0] );
        init_ac_vlc( j_ac_vlc[1][1][i], x8_ac1_lowquant_table [i][0] );
    }
#undef init_ac_vlc

//set dc tables
#define init_dc_vlc(dst,src) \
        init_vlc(&dst, \
        DC_VLC_BITS,34, \
        &src[1],4,2, \
        &src[0],4,2, \
        1);
    for(i=0;i<8;i++){
        init_dc_vlc( j_dc_vlc[0][i], x8_dc_highquant_table[i][0]);
        init_dc_vlc( j_dc_vlc[1][i], x8_dc_lowquant_table [i][0]);
    }
#undef init_dc_vlc

//set orient tables
#define init_or_vlc(dst,src) \
    init_vlc(&dst, \
    OR_VLC_BITS,12, \
    &src[1],4,2, \
    &src[0],4,2, \
    1);
    for(i=0;i<2;i++){
        init_or_vlc( j_orient_vlc[0][i], x8_orient_highquant_table[i][0]);
    }
    for(i=0;i<4;i++){
        init_or_vlc( j_orient_vlc[1][i], x8_orient_lowquant_table [i][0])
    }
}
#undef init_or_vlc

static void x8_reset_vlc_tables(IntraX8Context * w){
    memset(w->j_dc_vlc,0,sizeof(w->j_dc_vlc));
    memset(w->j_ac_vlc,0,sizeof(w->j_ac_vlc));
    w->j_orient_vlc=NULL;
}

static inline void x8_select_ac_table(IntraX8Context * const w , int mode){
    MpegEncContext * const s= w->s;
    int table_index;

    assert(mode<4);

    if( w->j_ac_vlc[mode] ) return;

    table_index = get_bits(&s->gb, 3);
    w->j_ac_vlc[mode] = &j_ac_vlc[w->quant<13][mode>>1][table_index];//2 modes use same tables
    assert(w->j_ac_vlc[mode]);
}

static inline int x8_get_orient_vlc(IntraX8Context * w){
    MpegEncContext * const s= w->s;
    int table_index;

    if(!w->j_orient_vlc ){
        table_index = get_bits(&s->gb, 1+(w->quant<13) );
        w->j_orient_vlc = &j_orient_vlc[w->quant<13][table_index];
    }
    assert(w->j_orient_vlc);
    assert(w->j_orient_vlc->table);

    return get_vlc2(&s->gb, w->j_orient_vlc->table, OR_VLC_BITS, OR_VLC_MTD);
}

#define extra_bits(eb) (eb)
#define extra_run   (0xFF<<8)
#define extra_level (0x00<<8)
#define   run_offset(r)    ((r)<<16)
#define level_offset(l)    ((l)<<24)
static const uint32_t ac_decode_table[]={
    /*46*/ extra_bits(3) |  extra_run  | run_offset(16) | level_offset( 0),
    /*47*/ extra_bits(3) |  extra_run  | run_offset(24) | level_offset( 0),
    /*48*/ extra_bits(2) |  extra_run  | run_offset( 4) | level_offset( 1),
    /*49*/ extra_bits(3) |  extra_run  | run_offset( 8) | level_offset( 1),

    /*50*/ extra_bits(5) |  extra_run  | run_offset(32) | level_offset( 0),
    /*51*/ extra_bits(4) |  extra_run  | run_offset(16) | level_offset( 1),

    /*52*/ extra_bits(2) | extra_level | run_offset( 0) | level_offset( 4),
    /*53*/ extra_bits(2) | extra_level | run_offset( 0) | level_offset( 8),
    /*54*/ extra_bits(2) | extra_level | run_offset( 0) | level_offset(12),
    /*55*/ extra_bits(3) | extra_level | run_offset( 0) | level_offset(16),
    /*56*/ extra_bits(3) | extra_level | run_offset( 0) | level_offset(24),

    /*57*/ extra_bits(2) | extra_level | run_offset( 1) | level_offset( 3),
    /*58*/ extra_bits(3) | extra_level | run_offset( 1) | level_offset( 7),

    /*59*/ extra_bits(2) |  extra_run  | run_offset(16) | level_offset( 0),
    /*60*/ extra_bits(2) |  extra_run  | run_offset(20) | level_offset( 0),
    /*61*/ extra_bits(2) |  extra_run  | run_offset(24) | level_offset( 0),
    /*62*/ extra_bits(2) |  extra_run  | run_offset(28) | level_offset( 0),
    /*63*/ extra_bits(4) |  extra_run  | run_offset(32) | level_offset( 0),
    /*64*/ extra_bits(4) |  extra_run  | run_offset(48) | level_offset( 0),

    /*65*/ extra_bits(2) |  extra_run  | run_offset( 4) | level_offset( 1),
    /*66*/ extra_bits(3) |  extra_run  | run_offset( 8) | level_offset( 1),
    /*67*/ extra_bits(4) |  extra_run  | run_offset(16) | level_offset( 1),

    /*68*/ extra_bits(2) | extra_level | run_offset( 0) | level_offset( 4),
    /*69*/ extra_bits(3) | extra_level | run_offset( 0) | level_offset( 8),
    /*70*/ extra_bits(4) | extra_level | run_offset( 0) | level_offset(16),

    /*71*/ extra_bits(2) | extra_level | run_offset( 1) | level_offset( 3),
    /*72*/ extra_bits(3) | extra_level | run_offset( 1) | level_offset( 7),
};
//extra_bits = 3bits; extra_run/level = 1 bit; run_offset = 6bits; level_offset = 5 bits;
#undef extra_bits
#undef extra_run
#undef extra_level
#undef run_offset
#undef level_offset

static void x8_get_ac_rlf(IntraX8Context * const w, const int mode,
                     int * const run, int * const level, int * const final){
    MpegEncContext *  const s= w->s;
    int i,e;

//    x8_select_ac_table(w,mode);
    i = get_vlc2(&s->gb, w->j_ac_vlc[mode]->table, AC_VLC_BITS, AC_VLC_MTD);

    if(i<46){ //[0-45]
        int t,l;
        if(i<0){
            (*level)=(*final)=//prevent 'may be used unilitialized'
            (*run)=64;//this would cause error exit in the ac loop
            return;
        }

        (*final) = t = (i>22);
        i-=23*t;
/*
  i== 0-15 r=0-15 l=0 ;r=i& %01111
  i==16-19 r=0-3  l=1 ;r=i& %00011
  i==20-21 r=0-1  l=2 ;r=i& %00001
  i==22    r=0    l=3 ;r=i& %00000
l=lut_l[i/2]={0,0,0,0,0,0,0,0,1,1,2,3}[i>>1];// 11 10'01 01'00 00'00 00'00 00'00 00 => 0xE50000
t=lut_mask[l]={0x0f,0x03,0x01,0x00}[l]; as i<256 the higher bits do not matter */
        l=(0xE50000>>(i&(0x1E)))&3;/*0x1E or (~1) or ((i>>1)<<1)*/
        t=(0x01030F>>(l<<3));

        (*run)   = i&t;
        (*level) = l;
    }else if(i<73){//[46-72]
        uint32_t sm;
        uint32_t mask;

        i-=46;
        sm=ac_decode_table[i];

        e=get_bits(&s->gb,sm&0xF);sm>>=8;//3bits
        mask=sm&0xff;sm>>=8;             //1bit

        (*run)  =(sm&0xff) + (e&( mask));//6bits
        (*level)=(sm>>8)   + (e&(~mask));//5bits
        (*final)=i>(58-46);
    }else if(i<75){//[73-74]
        static const uint8_t crazy_mix_runlevel[32]={
        0x22,0x32,0x33,0x53,0x23,0x42,0x43,0x63,
        0x24,0x52,0x34,0x73,0x25,0x62,0x44,0x83,
        0x26,0x72,0x35,0x54,0x27,0x82,0x45,0x64,
        0x28,0x92,0x36,0x74,0x29,0xa2,0x46,0x84};

        (*final)=!(i&1);
        e=get_bits(&s->gb,5);//get the extra bits
        (*run)  =crazy_mix_runlevel[e]>>4;
        (*level)=crazy_mix_runlevel[e]&0x0F;
    }else{
        (*level)=get_bits( &s->gb, 7-3*(i&1));
        (*run)  =get_bits( &s->gb, 6);
        (*final)=get_bits1(&s->gb);
    }
    return;
}

//static const uint8_t dc_extra_sbits[]   ={0, 1,1, 1,1, 2,2, 3,3,   4,4,   5,5,   6,6,    7,7    };
static const uint8_t dc_index_offset[]  ={ 0, 1,2, 3,4, 5,7, 9,13, 17,25, 33,49, 65,97, 129,193};

static int x8_get_dc_rlf(IntraX8Context * const w,int const mode, int * const level, int * const final){
    MpegEncContext * const s= w->s;
    int i,e,c;

    assert(mode<3);
    if( !w->j_dc_vlc[mode] ) {
        int table_index;
        table_index = get_bits(&s->gb, 3);
        //4 modes, same table
        w->j_dc_vlc[mode]= &j_dc_vlc[w->quant<13][table_index];
    }
    assert(w->j_dc_vlc);
    assert(w->j_dc_vlc[mode]->table);

    i=get_vlc2(&s->gb, w->j_dc_vlc[mode]->table, DC_VLC_BITS, DC_VLC_MTD);

    /*(i>=17) {i-=17;final=1;}*/
    c= i>16;
    (*final)=c;
    i-=17*c;

    if(i<=0){
        (*level)=0;
        return -i;
    }
    c=(i+1)>>1;//hackish way to calculate dc_extra_sbits[]
    c-=c>1;

    e=get_bits(&s->gb,c);//get the extra bits
    i=dc_index_offset[i]+(e>>1);

    e= -(e & 1);//0,0xffffff
    (*level)= (i ^ e) - e;// (i^0)-0 , (i^0xff)-(-1)
    return 0;
}
//end of huffman

static int x8_setup_spatial_predictor(IntraX8Context * const w, const int chroma){
    MpegEncContext * const s= w->s;
    int range;
    int sum;
    int quant;

    s->dsp.x8_setup_spatial_compensation(s->dest[chroma], s->edge_emu_buffer,
                                          s->current_picture.linesize[chroma>0],
                                          &range, &sum, w->edges);
    if(chroma){
        w->orient=w->chroma_orient;
        quant=w->quant_dc_chroma;
    }else{
        quant=w->quant;
    }

    w->flat_dc=0;
    if(range < quant || range < 3){
        w->orient=0;
        if(range < 3){//yep you read right, a +-1 idct error may break decoding!
            w->flat_dc=1;
            sum+=9;
            w->predicted_dc = (sum*6899)>>17;//((1<<17)+9)/(8+8+1+2)=6899
        }
    }
    if(chroma)
        return 0;

    assert(w->orient < 3);
    if(range < 2*w->quant){
        if( (w->edges&3) == 0){
            if(w->orient==1) w->orient=11;
            if(w->orient==2) w->orient=10;
        }else{
            w->orient=0;
        }
        w->raw_orient=0;
    }else{
        static const uint8_t prediction_table[3][12]={
            {0,8,4, 10,11, 2,6,9,1,3,5,7},
            {4,0,8, 11,10, 3,5,2,6,9,1,7},
            {8,0,4, 10,11, 1,7,2,6,9,3,5}
        };
        w->raw_orient=x8_get_orient_vlc(w);
        if(w->raw_orient<0) return -1;
        assert(w->raw_orient < 12 );
        assert(w->orient<3);
        w->orient=prediction_table[w->orient][w->raw_orient];
    }
    return 0;
}

static void x8_update_predictions(IntraX8Context * const w, const int orient, const int est_run ){
    MpegEncContext * const s= w->s;

    w->prediction_table[s->mb_x*2+(s->mb_y&1)] = (est_run<<2) + 1*(orient==4) + 2*(orient==8);
/*
  y=2n+0 ->//0 2 4
  y=2n+1 ->//1 3 5
*/
}
static void x8_get_prediction_chroma(IntraX8Context * const w){
    MpegEncContext * const s= w->s;

    w->edges = 1*( !(s->mb_x>>1) );
    w->edges|= 2*( !(s->mb_y>>1) );
    w->edges|= 4*( s->mb_x >= (2*s->mb_width-1) );//mb_x for chroma would always be odd

    w->raw_orient=0;
    if(w->edges&3){//lut_co[8]={inv,4,8,8, inv,4,8,8}<- =>{1,1,0,0;1,1,0,0} => 0xCC
        w->chroma_orient=4<<((0xCC>>w->edges)&1);
        return;
    }
    w->chroma_orient = (w->prediction_table[2*s->mb_x-2] & 0x03)<<2;//block[x-1][y|1-1)]
}

static void x8_get_prediction(IntraX8Context * const w){
    MpegEncContext * const s= w->s;
    int a,b,c,i;

    w->edges = 1*( !s->mb_x );
    w->edges|= 2*( !s->mb_y );
    w->edges|= 4*( s->mb_x >= (2*s->mb_width-1) );

    switch(w->edges&3){
        case 0:
            break;
        case 1:
            //take the one from the above block[0][y-1]
            w->est_run = w->prediction_table[!(s->mb_y&1)]>>2;
            w->orient  = 1;
            return;
        case 2:
            //take the one from the previous block[x-1][0]
            w->est_run = w->prediction_table[2*s->mb_x-2]>>2;
            w->orient  = 2;
            return;
        case 3:
            w->est_run = 16;
            w->orient  = 0;
            return;
    }
    //no edge cases
    b= w->prediction_table[2*s->mb_x   + !(s->mb_y&1) ];//block[x  ][y-1]
    a= w->prediction_table[2*s->mb_x-2 +  (s->mb_y&1) ];//block[x-1][y  ]
    c= w->prediction_table[2*s->mb_x-2 + !(s->mb_y&1) ];//block[x-1][y-1]

    w->est_run = FFMIN(b,a);
    /* This condition has nothing to do with w->edges, even if it looks