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Diffstat (limited to 'vp8/encoder/dct.c')
| -rw-r--r-- | vp8/encoder/dct.c | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/vp8/encoder/dct.c b/vp8/encoder/dct.c new file mode 100644 index 000000000..5207e39c4 --- /dev/null +++ b/vp8/encoder/dct.c @@ -0,0 +1,223 @@ +/* + * Copyright (c) 2010 The VP8 project authors. All Rights Reserved. + * + * Use of this source code is governed by a BSD-style license and patent + * grant that can be found in the LICENSE file in the root of the source + * tree. All contributing project authors may be found in the AUTHORS + * file in the root of the source tree. + */ + + +#include <math.h> + + +static const short dct_matrix2[4][4] = +{ + { 23170, 30274, 23170, 12540 }, + { 23170, 12540, -23170, -30274 }, + { 23170, -12540, -23170, 30274 }, + { 23170, -30274, 23170, -12540 } +}; + +static const short dct_matrix1[4][4] = +{ + { 23170, 23170, 23170, 23170 }, + { 30274, 12540, -12540, -30274 }, + { 23170, -23170, -23170, 23170 }, + { 12540, -30274, 30274, -12540 } +}; + + +#define _1STSTAGESHIFT 14 +#define _1STSTAGEROUNDING (1<<( _1STSTAGESHIFT-1)) +#define _2NDSTAGESHIFT 16 +#define _2NDSTAGEROUNDING (1<<( _2NDSTAGESHIFT-1)) + +// using matrix multiply +void vp8_short_fdct4x4_c(short *input, short *output, int pitch) +{ + int i, j, k; + short temp[4][4]; + int sumtemp; + pitch >>= 1; + + for (i = 0; i < 4; i++) + { + for (j = 0; j < 4; j++) + { + sumtemp = 0; + + for (k = 0; k < 4; k++) + { + sumtemp += input[i*pitch+k] * dct_matrix2[k][j]; + + } + + temp[i][j] = (short)((sumtemp + _1STSTAGEROUNDING) >> _1STSTAGESHIFT); + } + } + + + for (i = 0; i < 4; i++) + { + for (j = 0; j < 4; j++) + { + sumtemp = 0; + + for (k = 0; k < 4; k++) + { + sumtemp += dct_matrix1[i][ k] * temp[k][ j]; + } + + output[i*4+j] = (short)((sumtemp + _2NDSTAGEROUNDING) >> _2NDSTAGESHIFT); + } + } + +} + + +void vp8_short_fdct8x4_c(short *input, short *output, int pitch) +{ + vp8_short_fdct4x4_c(input, output, pitch); + vp8_short_fdct4x4_c(input + 4, output + 16, pitch); +} + + +static const signed short x_c1 = 60547; +static const signed short x_c2 = 46341; +static const signed short x_c3 = 25080; + +void vp8_fast_fdct4x4_c(short *input, short *output, int pitch) +{ + int i; + int a1, b1, c1, d1; + int a2, b2, c2, d2; + short *ip = input; + + short *op = output; + int temp1, temp2; + + for (i = 0; i < 4; i++) + { + a1 = (ip[0] + ip[3]) * 2; + b1 = (ip[1] + ip[2]) * 2; + c1 = (ip[1] - ip[2]) * 2; + d1 = (ip[0] - ip[3]) * 2; + + temp1 = a1 + b1; + temp2 = a1 - b1; + + op[0] = ((temp1 * x_c2) >> 16) + temp1; + op[2] = ((temp2 * x_c2) >> 16) + temp2; + + temp1 = (c1 * x_c3) >> 16; + temp2 = ((d1 * x_c1) >> 16) + d1; + + op[1] = temp1 + temp2; + + temp1 = (d1 * x_c3) >> 16; + temp2 = ((c1 * x_c1) >> 16) + c1; + + op[3] = temp1 - temp2; + + ip += pitch / 2; + op += 4; + } + + ip = output; + op = output; + + for (i = 0; i < 4; i++) + { + + a1 = ip[0] + ip[12]; + b1 = ip[4] + ip[8]; + c1 = ip[4] - ip[8]; + d1 = ip[0] - ip[12]; + + + temp1 = a1 + b1; + temp2 = a1 - b1; + + a2 = ((temp1 * x_c2) >> 16) + temp1; + c2 = ((temp2 * x_c2) >> 16) + temp2; + + temp1 = (c1 * x_c3) >> 16; + temp2 = ((d1 * x_c1) >> 16) + d1; + + b2 = temp1 + temp2; + + temp1 = (d1 * x_c3) >> 16; + temp2 = ((c1 * x_c1) >> 16) + c1; + + d2 = temp1 - temp2; + + + op[0] = (a2 + 1) >> 1; + op[4] = (b2 + 1) >> 1; + op[8] = (c2 + 1) >> 1; + op[12] = (d2 + 1) >> 1; + + ip++; + op++; + } +} + +void vp8_fast_fdct8x4_c(short *input, short *output, int pitch) +{ + vp8_fast_fdct4x4_c(input, output, pitch); + vp8_fast_fdct4x4_c(input + 4, output + 16, pitch); +} + +void vp8_short_walsh4x4_c(short *input, short *output, int pitch) +{ + int i; + int a1, b1, c1, d1; + int a2, b2, c2, d2; + short *ip = input; + short *op = output; + + for (i = 0; i < 4; i++) + { + a1 = ip[0] + ip[3]; + b1 = ip[1] + ip[2]; + c1 = ip[1] - ip[2]; + d1 = ip[0] - ip[3]; + + op[0] = a1 + b1; + op[1] = c1 + d1; + op[2] = a1 - b1; + op[3] = d1 - c1; + ip += pitch / 2; + op += 4; + } + + ip = output; + op = output; + + for (i = 0; i < 4; i++) + { + a1 = ip[0] + ip[12]; + b1 = ip[4] + ip[8]; + c1 = ip[4] - ip[8]; + d1 = ip[0] - ip[12]; + + a2 = a1 + b1; + b2 = c1 + d1; + c2 = a1 - b1; + d2 = d1 - c1; + + a2 += (a2 > 0); + b2 += (b2 > 0); + c2 += (c2 > 0); + d2 += (d2 > 0); + + op[0] = (a2) >> 1; + op[4] = (b2) >> 1; + op[8] = (c2) >> 1; + op[12] = (d2) >> 1; + + ip++; + op++; + } +} |