FFmpeg/libavcodec/vp3dsp.c

/*
 * Copyright (C) 2004 the ffmpeg project
 *
 * This library 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 of the License, or (at your option) any later version.
 *
 * This library 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 this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

/**
 * @file vp3dsp.c
 * Standard C DSP-oriented functions cribbed from the original VP3 
 * source code.
 */

#include "common.h"
#include "avcodec.h"
#include "dsputil.h"
#include "vp3data.h"

#define IdctAdjustBeforeShift 8
#define xC1S7 64277
#define xC2S6 60547
#define xC3S5 54491
#define xC4S4 46341
#define xC5S3 36410
#define xC6S2 25080
#define xC7S1 12785

static always_inline void idct(uint8_t *dst, int stride, int16_t *input, int type)
{
    int16_t *ip = input;
    uint8_t *cm = cropTbl + MAX_NEG_CROP;

    int A_, B_, C_, D_, _Ad, _Bd, _Cd, _Dd, E_, F_, G_, H_;
    int _Ed, _Gd, _Add, _Bdd, _Fd, _Hd;
    int t1, t2;

    int i, j;
    
    /* Inverse DCT on the rows now */
    for (i = 0; i < 8; i++) {
        /* Check for non-zero values */
        if ( ip[0] | ip[1] | ip[2] | ip[3] | ip[4] | ip[5] | ip[6] | ip[7] ) {
            t1 = (int32_t)(xC1S7 * ip[1]);
            t2 = (int32_t)(xC7S1 * ip[7]);
            t1 >>= 16;
            t2 >>= 16;
            A_ = t1 + t2;

            t1 = (int32_t)(xC7S1 * ip[1]);
            t2 = (int32_t)(xC1S7 * ip[7]);
            t1 >>= 16;
            t2 >>= 16;
            B_ = t1 - t2;

            t1 = (int32_t)(xC3S5 * ip[3]);
            t2 = (int32_t)(xC5S3 * ip[5]);
            t1 >>= 16;
            t2 >>= 16;
            C_ = t1 + t2;

            t1 = (int32_t)(xC3S5 * ip[5]);
            t2 = (int32_t)(xC5S3 * ip[3]);
            t1 >>= 16;
            t2 >>= 16;
            D_ = t1 - t2;


            t1 = (int32_t)(xC4S4 * (A_ - C_));
            t1 >>= 16;
            _Ad = t1;

            t1 = (int32_t)(xC4S4 * (B_ - D_));
            t1 >>= 16;
            _Bd = t1;


            _Cd = A_ + C_;
            _Dd = B_ + D_;

            t1 = (int32_t)(xC4S4 * (ip[0] + ip[4]));
            t1 >>= 16;
            E_ = t1;

            t1 = (int32_t)(xC4S4 * (ip[0] - ip[4]));
            t1 >>= 16;
            F_ = t1;

            t1 = (int32_t)(xC2S6 * ip[2]);
            t2 = (int32_t)(xC6S2 * ip[6]);
            t1 >>= 16;
            t2 >>= 16;
            G_ = t1 + t2;

            t1 = (int32_t)(xC6S2 * ip[2]);
            t2 = (int32_t)(xC2S6 * ip[6]);
            t1 >>= 16;
            t2 >>= 16;
            H_ = t1 - t2;


            _Ed = E_ - G_;
            _Gd = E_ + G_;

            _Add = F_ + _Ad;
            _Bdd = _Bd - H_;

            _Fd = F_ - _Ad;
            _Hd = _Bd + H_;

            /*  Final sequence of operations over-write original inputs. */
            ip[0] = _Gd + _Cd ;
            ip[7] = _Gd - _Cd ;

            ip[1] = _Add + _Hd;
            ip[2] = _Add - _Hd;

            ip[3] = _Ed + _Dd ;
            ip[4] = _Ed - _Dd ;

            ip[5] = _Fd + _Bdd;
            ip[6] = _Fd - _Bdd;

        }

        ip += 8;            /* next row */
    }
    
    ip = input;

    for ( i = 0; i < 8; i++) {
        /* Check for non-zero values (bitwise or faster than ||) */
        if ( ip[1 * 8] | ip[2 * 8] | ip[3 * 8] |
             ip[4 * 8] | ip[5 * 8] | ip[6 * 8] | ip[7 * 8] ) {

            t1 = (int32_t)(xC1S7 * ip[1*8]);
            t2 = (int32_t)(xC7S1 * ip[7*8]);
            t1 >>= 16;
            t2 >>= 16;
            A_ = t1 + t2;

            t1 = (int32_t)(xC7S1 * ip[1*8]);
            t2 = (int32_t)(xC1S7 * ip[7*8]);
            t1 >>= 16;
            t2 >>= 16;
            B_ = t1 - t2;

            t1 = (int32_t)(xC3S5 * ip[3*8]);
            t2 = (int32_t)(xC5S3 * ip[5*8]);
            t1 >>= 16;
            t2 >>= 16;
            C_ = t1 + t2;

            t1 = (int32_t)(xC3S5 * ip[5*8]);
            t2 = (int32_t)(xC5S3 * ip[3*8]);
            t1 >>= 16;
            t2 >>= 16;
            D_ = t1 - t2;


            t1 = (int32_t)(xC4S4 * (A_ - C_));
            t1 >>= 16;
            _Ad = t1;

            t1 = (int32_t)(xC4S4 * (B_ - D_));
            t1 >>= 16;
            _Bd = t1;


            _Cd = A_ + C_;
            _Dd = B_ + D_;

            t1 = (int32_t)(xC4S4 * (ip[0*8] + ip[4*8]));
            t1 >>= 16;
            E_ = t1;

            t1 = (int32_t)(xC4S4 * (ip[0*8] - ip[4*8]));
            t1 >>= 16;
            F_ = t1;

            t1 = (int32_t)(xC2S6 * ip[2*8]);
            t2 = (int32_t)(xC6S2 * ip[6*8]);
            t1 >>= 16;
            t2 >>= 16;
            G_ = t1 + t2;

            t1 = (int32_t)(xC6S2 * ip[2*8]);
            t2 = (int32_t)(xC2S6 * ip[6*8]);
            t1 >>= 16;
            t2 >>= 16;
            H_ = t1 - t2;


            _Ed = E_ - G_;
            _Gd = E_ + G_;

            _Add = F_ + _Ad;
            _Bdd = _Bd - H_;

            _Fd = F_ - _Ad;
            _Hd = _Bd + H_;

            if(type==1){  //HACK
                _Gd += 16*128;
                _Add+= 16*128;
                _Ed += 16*128;
                _Fd += 16*128;
            }
            _Gd += IdctAdjustBeforeShift;
            _Add += IdctAdjustBeforeShift;
            _Ed += IdctAdjustBeforeShift;
            _Fd += IdctAdjustBeforeShift;

            /* Final sequence of operations over-write original inputs. */
            if(type==0){
                ip[0*8] = (_Gd + _Cd )  >> 4;
                ip[7*8] = (_Gd - _Cd )  >> 4;
    
                ip[1*8] = (_Add + _Hd ) >> 4;
                ip[2*8] = (_Add - _Hd ) >> 4;
    
                ip[3*8] = (_Ed + _Dd )  >> 4;
                ip[4*8] = (_Ed - _Dd )  >> 4;
    
                ip[5*8] = (_Fd + _Bdd ) >> 4;
                ip[6*8] = (_Fd - _Bdd ) >> 4;
            }else if(type==1){
                dst[0*stride] = cm[(_Gd + _Cd )  >> 4];
                dst[7*stride] = cm[(_Gd - _Cd )  >> 4];
    
                dst[1*stride] = cm[(_Add + _Hd ) >> 4];
                dst[2*stride] = cm[(_Add - _Hd ) >> 4];
    
                dst[3*stride] = cm[(_Ed + _Dd )  >> 4];
                dst[4*stride] = cm[(_Ed - _Dd )  >> 4];
    
                dst[5*stride] = cm[(_Fd + _Bdd ) >> 4];
                dst[6*stride] = cm[(_Fd - _Bdd ) >> 4];
            }else{
                dst[0*stride] = cm[dst[0*stride] + ((_Gd + _Cd )  >> 4)];
                dst[7*stride] = cm[dst[7*stride] + ((_Gd - _Cd )  >> 4)];
    
                dst[1*stride] = cm[dst[1*stride] + ((_Add + _Hd ) >> 4)];
                dst[2*stride] = cm[dst[2*stride] + ((_Add - _Hd ) >> 4)];
    
                dst[3*stride] = cm[dst[3*stride] + ((_Ed + _Dd )  >> 4)];
                dst[4*stride] = cm[dst[4*stride] + ((_Ed - _Dd )  >> 4)];
    
                dst[5*stride] = cm[dst[5*stride] + ((_Fd + _Bdd ) >> 4)];
                dst[6*stride] = cm[dst[6*stride] + ((_Fd - _Bdd ) >> 4)];
            }

        } else {
            if(type==0){
                ip[0*8] = 
                ip[1*8] = 
                ip[2*8] = 
                ip[3*8] = 
                ip[4*8] = 
                ip[5*8] = 
                ip[6*8] =
                ip[7*8] = ((xC4S4 * ip[0*8] + (IdctAdjustBeforeShift<<16))>>20);
            }else if(type==1){
                dst[0*stride]=
                dst[1*stride]=
                dst[2*stride]=
                dst[3*stride]=
                dst[4*stride]=
                dst[5*stride]=
                dst[6*stride]=
                dst[7*stride]= 128 + ((xC4S4 * ip[0*8] + (IdctAdjustBeforeShift<<16))>>20);
            }else{
                if(ip[0*8]){
                    int v= ((xC4S4 * ip[0*8] + (IdctAdjustBeforeShift<<16))>>20);
                    dst[0*stride] = cm[dst[0*stride] + v];
                    dst[1*stride] = cm[dst[1*stride] + v];
                    dst[2*stride] = cm[dst[2*stride] + v];
                    dst[3*stride] = cm[dst[3*stride] + v];
                    dst[4*stride] = cm[dst[4*stride] + v];
                    dst[5*stride] = cm[dst[5*stride] + v];
                    dst[6*stride] = cm[dst[6*stride] + v];
                    dst[7*stride] = cm[dst[7*stride] + v];
                }
            }
        }

        ip++;            /* next column */
        dst++;
    }
}

void ff_vp3_idct_c(DCTELEM *block/* align 16*/){
    idct(NULL, 0, block, 0);
}
    
void ff_vp3_idct_put_c(uint8_t *dest/*align 8*/, int line_size, DCTELEM *block/*align 16*/){
    idct(dest, line_size, block, 1);
}

void ff_vp3_idct_add_c(uint8_t *dest/*align 8*/, int line_size, DCTELEM *block/*align 16*/){
    idct(dest, line_size, block, 2);
}