intrax8.c

ffmpeg移植到symbian的全部源代码

       similar it would trigger if e.g. x=3;y=2;
       I guess somebody wrote something wrong and it became standard. */
    if( (s->mb_x & s->mb_y) != 0 ) w->est_run=FFMIN(c,w->est_run);
    w->est_run>>=2;

    a&=3;
    b&=3;
    c&=3;

    i=( 0xFFEAF4C4>>(2*b+8*a) )&3;
    if(i!=3) w->orient=i;
    else     w->orient=( 0xFFEAD8>>(2*c+8*(w->quant>12)) )&3;
/*
lut1[b][a]={
->{0, 1, 0, pad},
  {0, 1, X, pad},
  {2, 2, 2, pad}}
   pad 2   2  2; pad X  1  0; pad 0  1  0 <-
-> 11 10 '10 10 '11 11'01 00 '11 00'01 00=>0xEAF4C4

lut2[q>12][c]={
  ->{0,2,1,pad},
    {2,2,2,pad}}
   pad 2  2  2; pad 1  2  0 <-
-> 11 10'10 10 '11 01'10 00=>0xEAD8
*/
}


static void x8_ac_compensation(IntraX8Context * const w, int const direction, int const dc_level){
    MpegEncContext * const s= w->s;
    int t;
#define B(x,y)  s->block[0][s->dsp.idct_permutation[(x)+(y)*8]]
#define T(x)  ((x) * dc_level + 0x8000) >> 16;
    switch(direction){
    case 0:
        t = T(3811);//h
        B(1,0) -= t;
        B(0,1) -= t;

        t = T(487);//e
        B(2,0) -= t;
        B(0,2) -= t;

        t = T(506);//f
        B(3,0) -= t;
        B(0,3) -= t;

        t = T(135);//c
        B(4,0) -= t;
        B(0,4) -= t;
        B(2,1) += t;
        B(1,2) += t;
        B(3,1) += t;
        B(1,3) += t;

        t = T(173);//d
        B(5,0) -= t;
        B(0,5) -= t;

        t = T(61);//b
        B(6,0) -= t;
        B(0,6) -= t;
        B(5,1) += t;
        B(1,5) += t;

        t = T(42); //a
        B(7,0) -= t;
        B(0,7) -= t;
        B(4,1) += t;
        B(1,4) += t;
        B(4,4) += t;

        t = T(1084);//g
        B(1,1) += t;

        s->block_last_index[0] = FFMAX(s->block_last_index[0], 7*8);
        break;
    case 1:
        B(0,1) -= T(6269);
        B(0,3) -= T( 708);
        B(0,5) -= T( 172);
        B(0,7) -= T(  73);

        s->block_last_index[0] = FFMAX(s->block_last_index[0], 7*8);
        break;
    case 2:
        B(1,0) -= T(6269);
        B(3,0) -= T( 708);
        B(5,0) -= T( 172);
        B(7,0) -= T(  73);

        s->block_last_index[0] = FFMAX(s->block_last_index[0], 7);
        break;
    }
#undef B
#undef T
}

static void dsp_x8_put_solidcolor(uint8_t const pix, uint8_t * dst, int const linesize){
    int k;
    for(k=0;k<8;k++){
        memset(dst,pix,8);
        dst+=linesize;
    }
}

static const int16_t quant_table[64] = {
    256, 256, 256, 256,  256, 256, 259, 262,
    265, 269, 272, 275,  278, 282, 285, 288,
    292, 295, 299, 303,  306, 310, 314, 317,
    321, 325, 329, 333,  337, 341, 345, 349,
    353, 358, 362, 366,  371, 375, 379, 384,
    389, 393, 398, 403,  408, 413, 417, 422,
    428, 433, 438, 443,  448, 454, 459, 465,
    470, 476, 482, 488,  493, 499, 505, 511
};

static int x8_decode_intra_mb(IntraX8Context* const w, const int chroma){
    MpegEncContext * const s= w->s;

    uint8_t * scantable;
    int final,run,level;
    int ac_mode,dc_mode,est_run,dc_level;
    int pos,n;
    int zeros_only;
    int use_quant_matrix;
    int sign;

    assert(w->orient<12);
    memset(s->block[0],0x00,64*sizeof(DCTELEM));

    if(chroma){
        dc_mode=2;
    }else{
        dc_mode=!!w->est_run;//0,1
    }

    if(x8_get_dc_rlf(w, dc_mode, &dc_level, &final)) return -1;
    n=0;
    zeros_only=0;
    if(!final){//decode ac
        use_quant_matrix=w->use_quant_matrix;
        if(chroma){
            ac_mode = 1;
            est_run = 64;//not used
        }else{
            if (w->raw_orient < 3){
                use_quant_matrix = 0;
            }
            if(w->raw_orient > 4){
                ac_mode = 0;
                est_run = 64;
            }else{
                if(w->est_run > 1){
                    ac_mode = 2;
                    est_run=w->est_run;
                }else{
                    ac_mode = 3;
                    est_run = 64;
                }
            }
        }
        x8_select_ac_table(w,ac_mode);
        /*scantable_selector[12]={0,2,0,1,1,1,0,2,2,0,1,2};<-
        -> 10'01' 00'10' 10'00' 01'01' 01'00' 10'00 =>0x928548 */
        scantable = w->scantable[ (0x928548>>(2*w->orient))&3 ].permutated;
        pos=0;
        do {
            n++;
            if( n >= est_run ){
                ac_mode=3;
                x8_select_ac_table(w,3);
            }

            x8_get_ac_rlf(w,ac_mode,&run,&level,&final);

            pos+=run+1;
            if(pos>63){
                //this also handles vlc error in x8_get_ac_rlf
                return -1;
            }
            level= (level+1) * w->dquant;
            level+= w->qsum;

            sign = - get_bits1(&s->gb);
            level = (level ^ sign) - sign;

            if(use_quant_matrix){
                level = (level*quant_table[pos])>>8;
            }
            s->block[0][ scantable[pos] ]=level;
        }while(!final);

        s->block_last_index[0]=pos;
    }else{//DC only
        s->block_last_index[0]=0;
        if(w->flat_dc && ((unsigned)(dc_level+1)) < 3){//[-1;1]
            int32_t divide_quant= !chroma ? w->divide_quant_dc_luma:
                                            w->divide_quant_dc_chroma;
            int32_t dc_quant    = !chroma ? w->quant:
                                            w->quant_dc_chroma;

            //original intent dc_level+=predicted_dc/quant; but it got lost somewhere in the rounding
            dc_level+= (w->predicted_dc*divide_quant + (1<<12) )>>13;

            dsp_x8_put_solidcolor( av_clip_uint8((dc_level*dc_quant+4)>>3),
                                   s->dest[chroma], s->current_picture.linesize[!!chroma]);

            goto block_placed;
        }
        zeros_only = (dc_level == 0);
    }
    if(!chroma){
        s->block[0][0] = dc_level*w->quant;
    }else{
        s->block[0][0] = dc_level*w->quant_dc_chroma;
    }

    //there is !zero_only check in the original, but dc_level check is enough
    if( (unsigned int)(dc_level+1) >= 3 && (w->edges&3) != 3 ){
        int direction;
        /*ac_comp_direction[orient] = { 0, 3, 3, 1, 1, 0, 0, 0, 2, 2, 2, 1 };<-
        -> 01'10' 10'10' 00'00' 00'01' 01'11' 11'00 =>0x6A017C */
        direction= (0x6A017C>>(w->orient*2))&3;
        if (direction != 3){
            x8_ac_compensation(w, direction, s->block[0][0]);//modify block_last[]
        }
    }

    if(w->flat_dc){
        dsp_x8_put_solidcolor(w->predicted_dc, s->dest[chroma], s->current_picture.linesize[!!chroma]);
    }else{
        s->dsp.x8_spatial_compensation[w->orient]( s->edge_emu_buffer,
                                            s->dest[chroma],
                                            s->current_picture.linesize[!!chroma] );
    }
    if(!zeros_only)
        s->dsp.idct_add ( s->dest[chroma],
                          s->current_picture.linesize[!!chroma],
                          s->block[0] );

block_placed:

    if(!chroma){
        x8_update_predictions(w,w->orient,n);
    }

    if(s->loop_filter){
        uint8_t* ptr = s->dest[chroma];
        int linesize = s->current_picture.linesize[!!chroma];

        if(!( (w->edges&2) || ( zeros_only && (w->orient|4)==4 ) )){
            s->dsp.x8_h_loop_filter(ptr, linesize, w->quant);
        }
        if(!( (w->edges&1) || ( zeros_only && (w->orient|8)==8 ) )){
            s->dsp.x8_v_loop_filter(ptr, linesize, w->quant);
        }
    }
    return 0;
}

static void x8_init_block_index(MpegEncContext *s){ //FIXME maybe merge with ff_*
//not s->linesize as this would be wrong for field pics
//not that IntraX8 has interlacing support ;)
    const int linesize  = s->current_picture.linesize[0];
    const int uvlinesize= s->current_picture.linesize[1];

    s->dest[0] = s->current_picture.data[0];
    s->dest[1] = s->current_picture.data[1];
    s->dest[2] = s->current_picture.data[2];

    s->dest[0] +=   s->mb_y        *   linesize << 3;
    s->dest[1] += ( s->mb_y&(~1) ) * uvlinesize << 2;//chroma blocks are on add rows
    s->dest[2] += ( s->mb_y&(~1) ) * uvlinesize << 2;
}

/**
 * Initialize IntraX8 frame decoder.
 * Requires valid MpegEncContext with valid s->mb_width before calling.
 * @param w pointer to IntraX8Context
 * @param s pointer to MpegEncContext of the parent codec
 */
void ff_intrax8_common_init(IntraX8Context * w, MpegEncContext * const s){

    w->s=s;
    x8_vlc_init();
    assert(s->mb_width>0);
    w->prediction_table=av_mallocz(s->mb_width*2*2);//two rows, 2 blocks per cannon mb

    ff_init_scantable(s->dsp.idct_permutation, &w->scantable[0], wmv1_scantable[0]);
    ff_init_scantable(s->dsp.idct_permutation, &w->scantable[1], wmv1_scantable[2]);
    ff_init_scantable(s->dsp.idct_permutation, &w->scantable[2], wmv1_scantable[3]);
}

/**
 * Destroy IntraX8 frame structure.
 * @param w pointer to IntraX8Context
 */
void ff_intrax8_common_end(IntraX8Context * w)
{
    av_freep(&w->prediction_table);
}

/**
 * Decode single IntraX8 frame.
 * The parent codec must fill s->loopfilter and s->gb (bitstream).
 * The parent codec must call MPV_frame_start(), ff_er_frame_start() before calling this function.
 * The parent codec must call ff_er_frame_end(), MPV_frame_end() after calling this function.
 * This function does not use MPV_decode_mb().
 * lowres decoding is theoretically impossible.
 * @param w pointer to IntraX8Context
 * @param dquant doubled quantizer, it would be odd in case of VC-1 halfpq==1.
 * @param quant_offset offset away from zero
 */
//FIXME extern uint8_t wmv3_dc_scale_table[32];
int ff_intrax8_decode_picture(IntraX8Context * const w, int dquant, int quant_offset){
    MpegEncContext * const s= w->s;
    int mb_xy;
    assert(s);
    w->use_quant_matrix = get_bits1(&s->gb);

    w->dquant = dquant;
    w->quant  = dquant >> 1;
    w->qsum   = quant_offset;

    w->divide_quant_dc_luma = ((1<<16) + (w->quant>>1)) / w->quant;
    if(w->quant < 5){
        w->quant_dc_chroma =  w->quant;
        w->divide_quant_dc_chroma = w->divide_quant_dc_luma;
    }else{
        w->quant_dc_chroma =  w->quant+((w->quant+3)>>3);
        w->divide_quant_dc_chroma = ((1<<16) + (w->quant_dc_chroma>>1)) / w->quant_dc_chroma;
    }
    x8_reset_vlc_tables(w);

    s->resync_mb_x=0;
    s->resync_mb_y=0;

    for(s->mb_y=0; s->mb_y < s->mb_height*2; s->mb_y++){
        x8_init_block_index(s);
        mb_xy=(s->mb_y>>1)*s->mb_stride;

        for(s->mb_x=0; s->mb_x < s->mb_width*2; s->mb_x++){
            x8_get_prediction(w);
            if(x8_setup_spatial_predictor(w,0)) goto error;
            if(x8_decode_intra_mb(w,0)) goto error;

            if( s->mb_x & s->mb_y & 1 ){
                x8_get_prediction_chroma(w);

                /*when setting up chroma, no vlc is read,
                so no error condition can be reached*/
                x8_setup_spatial_predictor(w,1);
                if(x8_decode_intra_mb(w,1)) goto error;

                x8_setup_spatial_predictor(w,2);
                if(x8_decode_intra_mb(w,2)) goto error;

                s->dest[1]+= 8;
                s->dest[2]+= 8;

                /*emulate MB info in the relevant tables*/
                s->mbskip_table [mb_xy]=0;
                s->mbintra_table[mb_xy]=1;
                s->current_picture.qscale_table[mb_xy]=w->quant;
                mb_xy++;
            }
            s->dest[0]+= 8;
        }
        if(s->mb_y&1){
            ff_draw_horiz_band(s, (s->mb_y-1)*8, 16);
        }
    }

error:
    ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y,
                        (s->mb_x>>1)-1, (s->mb_y>>1)-1,
                        (AC_END|DC_END|MV_END) );
    return 0;
}