GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/mdct15.c Lines: 145 179 81.0 %
Date: 2019-11-22 03:34:36 Branches: 34 56 60.7 %

Line Branch Exec Source
1
/*
2
 * Copyright (c) 2013-2014 Mozilla Corporation
3
 * Copyright (c) 2017 Rostislav Pehlivanov <atomnuker@gmail.com>
4
 *
5
 * This file is part of FFmpeg.
6
 *
7
 * FFmpeg is free software; you can redistribute it and/or
8
 * modify it under the terms of the GNU Lesser General Public
9
 * License as published by the Free Software Foundation; either
10
 * version 2.1 of the License, or (at your option) any later version.
11
 *
12
 * FFmpeg is distributed in the hope that it will be useful,
13
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15
 * Lesser General Public License for more details.
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 *
17
 * You should have received a copy of the GNU Lesser General Public
18
 * License along with FFmpeg; if not, write to the Free Software
19
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20
 */
21
22
/**
23
 * @file
24
 * Celt non-power of 2 iMDCT
25
 */
26
27
#include <float.h>
28
#include <math.h>
29
#include <stddef.h>
30
31
#include "config.h"
32
33
#include "libavutil/attributes.h"
34
#include "libavutil/common.h"
35
36
#include "mdct15.h"
37
38
#define FFT_FLOAT 1
39
#include "fft-internal.h"
40
41
#define CMUL3(c, a, b) CMUL((c).re, (c).im, (a).re, (a).im, (b).re, (b).im)
42
43
914
av_cold void ff_mdct15_uninit(MDCT15Context **ps)
44
{
45
914
    MDCT15Context *s = *ps;
46
47
914
    if (!s)
48
        return;
49
50
914
    ff_fft_end(&s->ptwo_fft);
51
52
914
    av_freep(&s->pfa_prereindex);
53
914
    av_freep(&s->pfa_postreindex);
54
914
    av_freep(&s->twiddle_exptab);
55
914
    av_freep(&s->tmp);
56
57
914
    av_freep(ps);
58
}
59
60
914
static inline int init_pfa_reindex_tabs(MDCT15Context *s)
61
{
62
    int i, j;
63
914
    const int b_ptwo = s->ptwo_fft.nbits; /* Bits for the power of two FFTs */
64
914
    const int l_ptwo = 1 << b_ptwo; /* Total length for the power of two FFTs */
65
914
    const int inv_1 = l_ptwo << ((4 - b_ptwo) & 3); /* (2^b_ptwo)^-1 mod 15 */
66
914
    const int inv_2 = 0xeeeeeeef & ((1U << b_ptwo) - 1); /* 15^-1 mod 2^b_ptwo */
67
68
914
    s->pfa_prereindex = av_malloc_array(15 * l_ptwo, sizeof(*s->pfa_prereindex));
69
914
    if (!s->pfa_prereindex)
70
        return 1;
71
72
914
    s->pfa_postreindex = av_malloc_array(15 * l_ptwo, sizeof(*s->pfa_postreindex));
73
914
    if (!s->pfa_postreindex)
74
        return 1;
75
76
    /* Pre/Post-reindex */
77
16374
    for (i = 0; i < l_ptwo; i++) {
78
247360
        for (j = 0; j < 15; j++) {
79
231900
            const int q_pre = ((l_ptwo * j)/15 + i) >> b_ptwo;
80
231900
            const int q_post = (((j*inv_1)/15) + (i*inv_2)) >> b_ptwo;
81
231900
            const int k_pre = 15*i + (j - q_pre*15)*(1 << b_ptwo);
82
231900
            const int k_post = i*inv_2*15 + j*inv_1 - 15*q_post*l_ptwo;
83
231900
            s->pfa_prereindex[i*15 + j] = k_pre << 1;
84
231900
            s->pfa_postreindex[k_post] = l_ptwo*j + i;
85
        }
86
    }
87
88
914
    return 0;
89
}
90
91
/* Stride is hardcoded to 3 */
92
2662464
static inline void fft5(FFTComplex *out, FFTComplex *in, FFTComplex exptab[2])
93
{
94
    FFTComplex z0[4], t[6];
95
96
2662464
    t[0].re = in[3].re + in[12].re;
97
2662464
    t[0].im = in[3].im + in[12].im;
98
2662464
    t[1].im = in[3].re - in[12].re;
99
2662464
    t[1].re = in[3].im - in[12].im;
100
2662464
    t[2].re = in[6].re + in[ 9].re;
101
2662464
    t[2].im = in[6].im + in[ 9].im;
102
2662464
    t[3].im = in[6].re - in[ 9].re;
103
2662464
    t[3].re = in[6].im - in[ 9].im;
104
105
2662464
    out[0].re = in[0].re + in[3].re + in[6].re + in[9].re + in[12].re;
106
2662464
    out[0].im = in[0].im + in[3].im + in[6].im + in[9].im + in[12].im;
107
108
2662464
    t[4].re = exptab[0].re * t[2].re - exptab[1].re * t[0].re;
109
2662464
    t[4].im = exptab[0].re * t[2].im - exptab[1].re * t[0].im;
110
2662464
    t[0].re = exptab[0].re * t[0].re - exptab[1].re * t[2].re;
111
2662464
    t[0].im = exptab[0].re * t[0].im - exptab[1].re * t[2].im;
112
2662464
    t[5].re = exptab[0].im * t[3].re - exptab[1].im * t[1].re;
113
2662464
    t[5].im = exptab[0].im * t[3].im - exptab[1].im * t[1].im;
114
2662464
    t[1].re = exptab[0].im * t[1].re + exptab[1].im * t[3].re;
115
2662464
    t[1].im = exptab[0].im * t[1].im + exptab[1].im * t[3].im;
116
117
2662464
    z0[0].re = t[0].re - t[1].re;
118
2662464
    z0[0].im = t[0].im - t[1].im;
119
2662464
    z0[1].re = t[4].re + t[5].re;
120
2662464
    z0[1].im = t[4].im + t[5].im;
121
122
2662464
    z0[2].re = t[4].re - t[5].re;
123
2662464
    z0[2].im = t[4].im - t[5].im;
124
2662464
    z0[3].re = t[0].re + t[1].re;
125
2662464
    z0[3].im = t[0].im + t[1].im;
126
127
2662464
    out[1].re = in[0].re + z0[3].re;
128
2662464
    out[1].im = in[0].im + z0[0].im;
129
2662464
    out[2].re = in[0].re + z0[2].re;
130
2662464
    out[2].im = in[0].im + z0[1].im;
131
2662464
    out[3].re = in[0].re + z0[1].re;
132
2662464
    out[3].im = in[0].im + z0[2].im;
133
2662464
    out[4].re = in[0].re + z0[0].re;
134
2662464
    out[4].im = in[0].im + z0[3].im;
135
2662464
}
136
137
887488
static void fft15_c(FFTComplex *out, FFTComplex *in, FFTComplex *exptab, ptrdiff_t stride)
138
{
139
    int k;
140
    FFTComplex tmp1[5], tmp2[5], tmp3[5];
141
142
887488
    fft5(tmp1, in + 0, exptab + 19);
143
887488
    fft5(tmp2, in + 1, exptab + 19);
144
887488
    fft5(tmp3, in + 2, exptab + 19);
145
146
5324928
    for (k = 0; k < 5; k++) {
147
        FFTComplex t[2];
148
149
4437440
        CMUL3(t[0], tmp2[k], exptab[k]);
150
4437440
        CMUL3(t[1], tmp3[k], exptab[2 * k]);
151
4437440
        out[stride*k].re = tmp1[k].re + t[0].re + t[1].re;
152
4437440
        out[stride*k].im = tmp1[k].im + t[0].im + t[1].im;
153
154
4437440
        CMUL3(t[0], tmp2[k], exptab[k + 5]);
155
4437440
        CMUL3(t[1], tmp3[k], exptab[2 * (k + 5)]);
156
4437440
        out[stride*(k + 5)].re = tmp1[k].re + t[0].re + t[1].re;
157
4437440
        out[stride*(k + 5)].im = tmp1[k].im + t[0].im + t[1].im;
158
159
4437440
        CMUL3(t[0], tmp2[k], exptab[k + 10]);
160
4437440
        CMUL3(t[1], tmp3[k], exptab[2 * k + 5]);
161
4437440
        out[stride*(k + 10)].re = tmp1[k].re + t[0].re + t[1].re;
162
4437440
        out[stride*(k + 10)].im = tmp1[k].im + t[0].im + t[1].im;
163
    }
164
887488
}
165
166
static void mdct15(MDCT15Context *s, float *dst, const float *src, ptrdiff_t stride)
167
{
168
    int i, j;
169
    const int len4 = s->len4, len3 = len4 * 3, len8 = len4 >> 1;
170
    const int l_ptwo = 1 << s->ptwo_fft.nbits;
171
    FFTComplex fft15in[15];
172
173
    /* Folding and pre-reindexing */
174
    for (i = 0; i < l_ptwo; i++) {
175
        for (j = 0; j < 15; j++) {
176
            const int k = s->pfa_prereindex[i*15 + j];
177
            FFTComplex tmp, exp = s->twiddle_exptab[k >> 1];
178
            if (k < len4) {
179
                tmp.re = -src[ len4 + k] + src[1*len4 - 1 - k];
180
                tmp.im = -src[ len3 + k] - src[1*len3 - 1 - k];
181
            } else {
182
                tmp.re = -src[ len4 + k] - src[5*len4 - 1 - k];
183
                tmp.im =  src[-len4 + k] - src[1*len3 - 1 - k];
184
            }
185
            CMUL(fft15in[j].im, fft15in[j].re, tmp.re, tmp.im, exp.re, exp.im);
186
        }
187
        s->fft15(s->tmp + s->ptwo_fft.revtab[i], fft15in, s->exptab, l_ptwo);
188
    }
189
190
    /* Then a 15xN FFT (where N is a power of two) */
191
    for (i = 0; i < 15; i++)
192
        s->ptwo_fft.fft_calc(&s->ptwo_fft, s->tmp + l_ptwo*i);
193
194
    /* Reindex again, apply twiddles and output */
195
    for (i = 0; i < len8; i++) {
196
        const int i0 = len8 + i, i1 = len8 - i - 1;
197
        const int s0 = s->pfa_postreindex[i0], s1 = s->pfa_postreindex[i1];
198
199
        CMUL(dst[2*i1*stride + stride], dst[2*i0*stride], s->tmp[s0].re, s->tmp[s0].im,
200
             s->twiddle_exptab[i0].im, s->twiddle_exptab[i0].re);
201
        CMUL(dst[2*i0*stride + stride], dst[2*i1*stride], s->tmp[s1].re, s->tmp[s1].im,
202
             s->twiddle_exptab[i1].im, s->twiddle_exptab[i1].re);
203
    }
204
}
205
206
99968
static void imdct15_half(MDCT15Context *s, float *dst, const float *src,
207
                         ptrdiff_t stride)
208
{
209
    FFTComplex fft15in[15];
210
99968
    FFTComplex *z = (FFTComplex *)dst;
211
99968
    int i, j, len8 = s->len4 >> 1, l_ptwo = 1 << s->ptwo_fft.nbits;
212
99968
    const float *in1 = src, *in2 = src + (s->len2 - 1) * stride;
213
214
    /* Reindex input, putting it into a buffer and doing an Nx15 FFT */
215
987456
    for (i = 0; i < l_ptwo; i++) {
216
14199808
        for (j = 0; j < 15; j++) {
217
13312320
            const int k = s->pfa_prereindex[i*15 + j];
218
13312320
            FFTComplex tmp = { in2[-k*stride], in1[k*stride] };
219
13312320
            CMUL3(fft15in[j], tmp, s->twiddle_exptab[k >> 1]);
220
        }
221
887488
        s->fft15(s->tmp + s->ptwo_fft.revtab[i], fft15in, s->exptab, l_ptwo);
222
    }
223
224
    /* Then a 15xN FFT (where N is a power of two) */
225
1599488
    for (i = 0; i < 15; i++)
226
1499520
        s->ptwo_fft.fft_calc(&s->ptwo_fft, s->tmp + l_ptwo*i);
227
228
    /* Reindex again, apply twiddles and output */
229
99968
    s->postreindex(z, s->tmp, s->twiddle_exptab, s->pfa_postreindex, len8);
230
99968
}
231
232
99968
static void postrotate_c(FFTComplex *out, FFTComplex *in, FFTComplex *exp,
233
                         int *lut, ptrdiff_t len8)
234
{
235
    int i;
236
237
    /* Reindex again, apply twiddles and output */
238
6756128
    for (i = 0; i < len8; i++) {
239
6656160
        const int i0 = len8 + i, i1 = len8 - i - 1;
240
6656160
        const int s0 = lut[i0], s1 = lut[i1];
241
242
6656160
        CMUL(out[i1].re, out[i0].im, in[s1].im, in[s1].re, exp[i1].im, exp[i1].re);
243
6656160
        CMUL(out[i0].re, out[i1].im, in[s0].im, in[s0].re, exp[i0].im, exp[i0].re);
244
    }
245
99968
}
246
247
914
av_cold int ff_mdct15_init(MDCT15Context **ps, int inverse, int N, double scale)
248
{
249
    MDCT15Context *s;
250
    double alpha, theta;
251
914
    int len2 = 15 * (1 << N);
252
914
    int len  = 2 * len2;
253
    int i;
254
255
    /* Tested and verified to work on everything in between */
256

914
    if ((N < 2) || (N > 13))
257
        return AVERROR(EINVAL);
258
259
914
    s = av_mallocz(sizeof(*s));
260
914
    if (!s)
261
        return AVERROR(ENOMEM);
262
263
914
    s->fft_n       = N - 1;
264
914
    s->len4        = len2 / 2;
265
914
    s->len2        = len2;
266
914
    s->inverse     = inverse;
267
914
    s->fft15       = fft15_c;
268
914
    s->mdct        = mdct15;
269
914
    s->imdct_half  = imdct15_half;
270
914
    s->postreindex = postrotate_c;
271
272
914
    if (ff_fft_init(&s->ptwo_fft, N - 1, s->inverse) < 0)
273
        goto fail;
274
275
914
    if (init_pfa_reindex_tabs(s))
276
        goto fail;
277
278
914
    s->tmp  = av_malloc_array(len, 2 * sizeof(*s->tmp));
279
914
    if (!s->tmp)
280
        goto fail;
281
282
914
    s->twiddle_exptab = av_malloc_array(s->len4, sizeof(*s->twiddle_exptab));
283
914
    if (!s->twiddle_exptab)
284
        goto fail;
285
286
914
    theta = 0.125f + (scale < 0 ? s->len4 : 0);
287
914
    scale = sqrt(fabs(scale));
288
232814
    for (i = 0; i < s->len4; i++) {
289
231900
        alpha = 2 * M_PI * (i + theta) / len;
290
231900
        s->twiddle_exptab[i].re = cosf(alpha) * scale;
291
231900
        s->twiddle_exptab[i].im = sinf(alpha) * scale;
292
    }
293
294
    /* 15-point FFT exptab */
295
18280
    for (i = 0; i < 19; i++) {
296
17366
        if (i < 15) {
297
13710
            double theta = (2.0f * M_PI * i) / 15.0f;
298
13710
            if (!s->inverse)
299
                theta *= -1;
300
13710
            s->exptab[i].re = cosf(theta);
301
13710
            s->exptab[i].im = sinf(theta);
302
        } else { /* Wrap around to simplify fft15 */
303
3656
            s->exptab[i] = s->exptab[i - 15];
304
        }
305
    }
306
307
    /* 5-point FFT exptab */
308
914
    s->exptab[19].re = cosf(2.0f * M_PI / 5.0f);
309
914
    s->exptab[19].im = sinf(2.0f * M_PI / 5.0f);
310
914
    s->exptab[20].re = cosf(1.0f * M_PI / 5.0f);
311
914
    s->exptab[20].im = sinf(1.0f * M_PI / 5.0f);
312
313
    /* Invert the phase for an inverse transform, do nothing for a forward transform */
314
914
    if (s->inverse) {
315
914
        s->exptab[19].im *= -1;
316
914
        s->exptab[20].im *= -1;
317
    }
318
319
    if (ARCH_X86)
320
914
        ff_mdct15_init_x86(s);
321
322
914
    *ps = s;
323
324
914
    return 0;
325
326
fail:
327
    ff_mdct15_uninit(&s);
328
    return AVERROR(ENOMEM);
329
}