summaryrefslogtreecommitdiff
path: root/lib/rbcodec/codecs/libwmavoice/dct.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/rbcodec/codecs/libwmavoice/dct.c')
-rw-r--r--lib/rbcodec/codecs/libwmavoice/dct.c226
1 files changed, 226 insertions, 0 deletions
diff --git a/lib/rbcodec/codecs/libwmavoice/dct.c b/lib/rbcodec/codecs/libwmavoice/dct.c
new file mode 100644
index 0000000000..95aef5af6c
--- /dev/null
+++ b/lib/rbcodec/codecs/libwmavoice/dct.c
@@ -0,0 +1,226 @@
1/*
2 * (I)DCT Transforms
3 * Copyright (c) 2009 Peter Ross <pross@xvid.org>
4 * Copyright (c) 2010 Alex Converse <alex.converse@gmail.com>
5 * Copyright (c) 2010 Vitor Sessak
6 *
7 * This file is part of FFmpeg.
8 *
9 * FFmpeg is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
13 *
14 * FFmpeg is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Lesser General Public License for more details.
18 *
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with FFmpeg; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24/**
25 * @file
26 * (Inverse) Discrete Cosine Transforms. These are also known as the
27 * type II and type III DCTs respectively.
28 */
29
30#include <math.h>
31#include "libavutil/mathematics.h"
32#include "fft.h"
33//#include "x86/fft.h"
34
35#define DCT32_FLOAT
36#include "dct32.c"
37
38/* sin((M_PI * x / (2*n)) */
39#define SIN(s,n,x) (s->costab[(n) - (x)])
40
41/* cos((M_PI * x / (2*n)) */
42#define COS(s,n,x) (s->costab[x])
43
44static void ff_dst_calc_I_c(DCTContext *ctx, FFTSample *data)
45{
46 int n = 1 << ctx->nbits;
47 int i;
48
49 data[0] = 0;
50 for(i = 1; i < n/2; i++) {
51 float tmp1 = data[i ];
52 float tmp2 = data[n - i];
53 float s = SIN(ctx, n, 2*i);
54
55 s *= tmp1 + tmp2;
56 tmp1 = (tmp1 - tmp2) * 0.5f;
57 data[i ] = s + tmp1;
58 data[n - i] = s - tmp1;
59 }
60
61 data[n/2] *= 2;
62 ff_rdft_calc(&ctx->rdft, data);
63
64 data[0] *= 0.5f;
65
66 for(i = 1; i < n-2; i += 2) {
67 data[i + 1] += data[i - 1];
68 data[i ] = -data[i + 2];
69 }
70
71 data[n-1] = 0;
72}
73
74static void ff_dct_calc_I_c(DCTContext *ctx, FFTSample *data)
75{
76 int n = 1 << ctx->nbits;
77 int i;
78 float next = -0.5f * (data[0] - data[n]);
79
80 for(i = 0; i < n/2; i++) {
81 float tmp1 = data[i ];
82 float tmp2 = data[n - i];
83 float s = SIN(ctx, n, 2*i);
84 float c = COS(ctx, n, 2*i);
85
86 c *= tmp1 - tmp2;
87 s *= tmp1 - tmp2;
88
89 next += c;
90
91 tmp1 = (tmp1 + tmp2) * 0.5f;
92 data[i ] = tmp1 - s;
93 data[n - i] = tmp1 + s;
94 }
95
96 ff_rdft_calc(&ctx->rdft, data);
97 data[n] = data[1];
98 data[1] = next;
99
100 for(i = 3; i <= n; i += 2)
101 data[i] = data[i - 2] - data[i];
102}
103
104static void ff_dct_calc_III_c(DCTContext *ctx, FFTSample *data)
105{
106 int n = 1 << ctx->nbits;
107 int i;
108
109 float next = data[n - 1];
110 float inv_n = 1.0f / n;
111
112 for (i = n - 2; i >= 2; i -= 2) {
113 float val1 = data[i ];
114 float val2 = data[i - 1] - data[i + 1];
115 float c = COS(ctx, n, i);
116 float s = SIN(ctx, n, i);
117
118 data[i ] = c * val1 + s * val2;
119 data[i + 1] = s * val1 - c * val2;
120 }
121
122 data[1] = 2 * next;
123
124 ff_rdft_calc(&ctx->rdft, data);
125
126 for (i = 0; i < n / 2; i++) {
127 float tmp1 = data[i ] * inv_n;
128 float tmp2 = data[n - i - 1] * inv_n;
129 float csc = ctx->csc2[i] * (tmp1 - tmp2);
130
131 tmp1 += tmp2;
132 data[i ] = tmp1 + csc;
133 data[n - i - 1] = tmp1 - csc;
134 }
135}
136
137static void ff_dct_calc_II_c(DCTContext *ctx, FFTSample *data)
138{
139 int n = 1 << ctx->nbits;
140 int i;
141 float next;
142
143 for (i=0; i < n/2; i++) {
144 float tmp1 = data[i ];
145 float tmp2 = data[n - i - 1];
146 float s = SIN(ctx, n, 2*i + 1);
147
148 s *= tmp1 - tmp2;
149 tmp1 = (tmp1 + tmp2) * 0.5f;
150
151 data[i ] = tmp1 + s;
152 data[n-i-1] = tmp1 - s;
153 }
154
155 ff_rdft_calc(&ctx->rdft, data);
156
157 next = data[1] * 0.5;
158 data[1] *= -1;
159
160 for (i = n - 2; i >= 0; i -= 2) {
161 float inr = data[i ];
162 float ini = data[i + 1];
163 float c = COS(ctx, n, i);
164 float s = SIN(ctx, n, i);
165
166 data[i ] = c * inr + s * ini;
167
168 data[i+1] = next;
169
170 next += s * inr - c * ini;
171 }
172}
173
174static void dct32_func(DCTContext *ctx, FFTSample *data)
175{
176 ctx->dct32(data, data);
177}
178
179void ff_dct_calc(DCTContext *s, FFTSample *data)
180{
181 s->dct_calc(s, data);
182}
183
184av_cold int ff_dct_init(DCTContext *s, int nbits, enum DCTTransformType inverse)
185{
186 int n = 1 << nbits;
187 int i;
188
189 s->nbits = nbits;
190 s->inverse = inverse;
191
192 ff_init_ff_cos_tabs(nbits+2);
193
194 s->costab = ff_cos_tabs[nbits+2];
195
196 s->csc2 = av_malloc(n/2 * sizeof(FFTSample));
197
198 if (ff_rdft_init(&s->rdft, nbits, inverse == DCT_III) < 0) {
199 av_free(s->csc2);
200 return -1;
201 }
202
203 for (i = 0; i < n/2; i++)
204 s->csc2[i] = 0.5 / sin((M_PI / (2*n) * (2*i + 1)));
205
206 switch(inverse) {
207 case DCT_I : s->dct_calc = ff_dct_calc_I_c; break;
208 case DCT_II : s->dct_calc = ff_dct_calc_II_c ; break;
209 case DCT_III: s->dct_calc = ff_dct_calc_III_c; break;
210 case DST_I : s->dct_calc = ff_dst_calc_I_c; break;
211 }
212
213 if (inverse == DCT_II && nbits == 5)
214 s->dct_calc = dct32_func;
215
216 s->dct32 = dct32;
217 //if (HAVE_MMX) ff_dct_init_mmx(s);
218
219 return 0;
220}
221
222av_cold void ff_dct_end(DCTContext *s)
223{
224 ff_rdft_end(&s->rdft);
225 av_free(s->csc2);
226}