michael@0: /*
michael@0:  *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
michael@0:  *
michael@0:  *  Use of this source code is governed by a BSD-style license
michael@0:  *  that can be found in the LICENSE file in the root of the source
michael@0:  *  tree. An additional intellectual property rights grant can be found
michael@0:  *  in the file PATENTS.  All contributing project authors may
michael@0:  *  be found in the AUTHORS file in the root of the source tree.
michael@0:  */
michael@0: 
michael@0: 
michael@0: #include <math.h>
michael@0: 
michael@0: void vp8_short_fdct4x4_c(short *input, short *output, int pitch)
michael@0: {
michael@0:     int i;
michael@0:     int a1, b1, c1, d1;
michael@0:     short *ip = input;
michael@0:     short *op = output;
michael@0: 
michael@0:     for (i = 0; i < 4; i++)
michael@0:     {
michael@0:         a1 = ((ip[0] + ip[3]) * 8);
michael@0:         b1 = ((ip[1] + ip[2]) * 8);
michael@0:         c1 = ((ip[1] - ip[2]) * 8);
michael@0:         d1 = ((ip[0] - ip[3]) * 8);
michael@0: 
michael@0:         op[0] = a1 + b1;
michael@0:         op[2] = a1 - b1;
michael@0: 
michael@0:         op[1] = (c1 * 2217 + d1 * 5352 +  14500)>>12;
michael@0:         op[3] = (d1 * 2217 - c1 * 5352 +   7500)>>12;
michael@0: 
michael@0:         ip += pitch / 2;
michael@0:         op += 4;
michael@0: 
michael@0:     }
michael@0:     ip = output;
michael@0:     op = output;
michael@0:     for (i = 0; i < 4; i++)
michael@0:     {
michael@0:         a1 = ip[0] + ip[12];
michael@0:         b1 = ip[4] + ip[8];
michael@0:         c1 = ip[4] - ip[8];
michael@0:         d1 = ip[0] - ip[12];
michael@0: 
michael@0:         op[0]  = ( a1 + b1 + 7)>>4;
michael@0:         op[8]  = ( a1 - b1 + 7)>>4;
michael@0: 
michael@0:         op[4]  =((c1 * 2217 + d1 * 5352 +  12000)>>16) + (d1!=0);
michael@0:         op[12] = (d1 * 2217 - c1 * 5352 +  51000)>>16;
michael@0: 
michael@0:         ip++;
michael@0:         op++;
michael@0:     }
michael@0: }
michael@0: 
michael@0: void vp8_short_fdct8x4_c(short *input, short *output, int pitch)
michael@0: {
michael@0:     vp8_short_fdct4x4_c(input,   output,    pitch);
michael@0:     vp8_short_fdct4x4_c(input + 4, output + 16, pitch);
michael@0: }
michael@0: 
michael@0: void vp8_short_walsh4x4_c(short *input, short *output, int pitch)
michael@0: {
michael@0:     int i;
michael@0:     int a1, b1, c1, d1;
michael@0:     int a2, b2, c2, d2;
michael@0:     short *ip = input;
michael@0:     short *op = output;
michael@0: 
michael@0: 
michael@0:     for (i = 0; i < 4; i++)
michael@0:     {
michael@0:         a1 = ((ip[0] + ip[2]) * 4);
michael@0:         d1 = ((ip[1] + ip[3]) * 4);
michael@0:         c1 = ((ip[1] - ip[3]) * 4);
michael@0:         b1 = ((ip[0] - ip[2]) * 4);
michael@0: 
michael@0:         op[0] = a1 + d1 + (a1!=0);
michael@0:         op[1] = b1 + c1;
michael@0:         op[2] = b1 - c1;
michael@0:         op[3] = a1 - d1;
michael@0:         ip += pitch / 2;
michael@0:         op += 4;
michael@0:     }
michael@0: 
michael@0:     ip = output;
michael@0:     op = output;
michael@0: 
michael@0:     for (i = 0; i < 4; i++)
michael@0:     {
michael@0:         a1 = ip[0] + ip[8];
michael@0:         d1 = ip[4] + ip[12];
michael@0:         c1 = ip[4] - ip[12];
michael@0:         b1 = ip[0] - ip[8];
michael@0: 
michael@0:         a2 = a1 + d1;
michael@0:         b2 = b1 + c1;
michael@0:         c2 = b1 - c1;
michael@0:         d2 = a1 - d1;
michael@0: 
michael@0:         a2 += a2<0;
michael@0:         b2 += b2<0;
michael@0:         c2 += c2<0;
michael@0:         d2 += d2<0;
michael@0: 
michael@0:         op[0] = (a2+3) >> 3;
michael@0:         op[4] = (b2+3) >> 3;
michael@0:         op[8] = (c2+3) >> 3;
michael@0:         op[12]= (d2+3) >> 3;
michael@0: 
michael@0:         ip++;
michael@0:         op++;
michael@0:     }
michael@0: }