| /* |
| * Copyright (c) 2013-2014 Mozilla Corporation |
| * |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg 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 2.1 of the License, or (at your option) any later version. |
| * |
| * FFmpeg 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 FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| /** |
| * @file |
| * Celt non-power of 2 iMDCT |
| */ |
| |
| #include <float.h> |
| #include <math.h> |
| #include <stddef.h> |
| |
| #include "config.h" |
| |
| #include "libavutil/attributes.h" |
| #include "libavutil/common.h" |
| |
| #include "avfft.h" |
| #include "imdct15.h" |
| #include "opus.h" |
| |
| // minimal iMDCT size to make SIMD opts easier |
| #define CELT_MIN_IMDCT_SIZE 120 |
| |
| // complex c = a * b |
| #define CMUL3(cre, cim, are, aim, bre, bim) \ |
| do { \ |
| cre = are * bre - aim * bim; \ |
| cim = are * bim + aim * bre; \ |
| } while (0) |
| |
| #define CMUL(c, a, b) CMUL3((c).re, (c).im, (a).re, (a).im, (b).re, (b).im) |
| |
| // complex c = a * b |
| // d = a * conjugate(b) |
| #define CMUL2(c, d, a, b) \ |
| do { \ |
| float are = (a).re; \ |
| float aim = (a).im; \ |
| float bre = (b).re; \ |
| float bim = (b).im; \ |
| float rr = are * bre; \ |
| float ri = are * bim; \ |
| float ir = aim * bre; \ |
| float ii = aim * bim; \ |
| (c).re = rr - ii; \ |
| (c).im = ri + ir; \ |
| (d).re = rr + ii; \ |
| (d).im = -ri + ir; \ |
| } while (0) |
| |
| av_cold void ff_imdct15_uninit(IMDCT15Context **ps) |
| { |
| IMDCT15Context *s = *ps; |
| int i; |
| |
| if (!s) |
| return; |
| |
| for (i = 0; i < FF_ARRAY_ELEMS(s->exptab); i++) |
| av_freep(&s->exptab[i]); |
| |
| av_freep(&s->twiddle_exptab); |
| |
| av_freep(&s->tmp); |
| |
| av_freep(ps); |
| } |
| |
| static void imdct15_half(IMDCT15Context *s, float *dst, const float *src, |
| ptrdiff_t stride, float scale); |
| |
| av_cold int ff_imdct15_init(IMDCT15Context **ps, int N) |
| { |
| IMDCT15Context *s; |
| int len2 = 15 * (1 << N); |
| int len = 2 * len2; |
| int i, j; |
| |
| if (len2 > CELT_MAX_FRAME_SIZE || len2 < CELT_MIN_IMDCT_SIZE) |
| return AVERROR(EINVAL); |
| |
| s = av_mallocz(sizeof(*s)); |
| if (!s) |
| return AVERROR(ENOMEM); |
| |
| s->fft_n = N - 1; |
| s->len4 = len2 / 2; |
| s->len2 = len2; |
| |
| s->tmp = av_malloc_array(len, 2 * sizeof(*s->tmp)); |
| if (!s->tmp) |
| goto fail; |
| |
| s->twiddle_exptab = av_malloc_array(s->len4, sizeof(*s->twiddle_exptab)); |
| if (!s->twiddle_exptab) |
| goto fail; |
| |
| for (i = 0; i < s->len4; i++) { |
| s->twiddle_exptab[i].re = cos(2 * M_PI * (i + 0.125 + s->len4) / len); |
| s->twiddle_exptab[i].im = sin(2 * M_PI * (i + 0.125 + s->len4) / len); |
| } |
| |
| for (i = 0; i < FF_ARRAY_ELEMS(s->exptab); i++) { |
| int N = 15 * (1 << i); |
| s->exptab[i] = av_malloc(sizeof(*s->exptab[i]) * FFMAX(N, 19)); |
| if (!s->exptab[i]) |
| goto fail; |
| |
| for (j = 0; j < N; j++) { |
| s->exptab[i][j].re = cos(2 * M_PI * j / N); |
| s->exptab[i][j].im = sin(2 * M_PI * j / N); |
| } |
| } |
| |
| // wrap around to simplify fft15 |
| for (j = 15; j < 19; j++) |
| s->exptab[0][j] = s->exptab[0][j - 15]; |
| |
| s->imdct_half = imdct15_half; |
| |
| if (ARCH_AARCH64) |
| ff_imdct15_init_aarch64(s); |
| |
| *ps = s; |
| |
| return 0; |
| |
| fail: |
| ff_imdct15_uninit(&s); |
| return AVERROR(ENOMEM); |
| } |
| |
| static void fft5(FFTComplex *out, const FFTComplex *in, ptrdiff_t stride) |
| { |
| // [0] = exp(2 * i * pi / 5), [1] = exp(2 * i * pi * 2 / 5) |
| static const FFTComplex fact[] = { { 0.30901699437494745, 0.95105651629515353 }, |
| { -0.80901699437494734, 0.58778525229247325 } }; |
| |
| FFTComplex z[4][4]; |
| |
| CMUL2(z[0][0], z[0][3], in[1 * stride], fact[0]); |
| CMUL2(z[0][1], z[0][2], in[1 * stride], fact[1]); |
| CMUL2(z[1][0], z[1][3], in[2 * stride], fact[0]); |
| CMUL2(z[1][1], z[1][2], in[2 * stride], fact[1]); |
| CMUL2(z[2][0], z[2][3], in[3 * stride], fact[0]); |
| CMUL2(z[2][1], z[2][2], in[3 * stride], fact[1]); |
| CMUL2(z[3][0], z[3][3], in[4 * stride], fact[0]); |
| CMUL2(z[3][1], z[3][2], in[4 * stride], fact[1]); |
| |
| out[0].re = in[0].re + in[stride].re + in[2 * stride].re + in[3 * stride].re + in[4 * stride].re; |
| out[0].im = in[0].im + in[stride].im + in[2 * stride].im + in[3 * stride].im + in[4 * stride].im; |
| |
| out[1].re = in[0].re + z[0][0].re + z[1][1].re + z[2][2].re + z[3][3].re; |
| out[1].im = in[0].im + z[0][0].im + z[1][1].im + z[2][2].im + z[3][3].im; |
| |
| out[2].re = in[0].re + z[0][1].re + z[1][3].re + z[2][0].re + z[3][2].re; |
| out[2].im = in[0].im + z[0][1].im + z[1][3].im + z[2][0].im + z[3][2].im; |
| |
| out[3].re = in[0].re + z[0][2].re + z[1][0].re + z[2][3].re + z[3][1].re; |
| out[3].im = in[0].im + z[0][2].im + z[1][0].im + z[2][3].im + z[3][1].im; |
| |
| out[4].re = in[0].re + z[0][3].re + z[1][2].re + z[2][1].re + z[3][0].re; |
| out[4].im = in[0].im + z[0][3].im + z[1][2].im + z[2][1].im + z[3][0].im; |
| } |
| |
| static void fft15(IMDCT15Context *s, FFTComplex *out, const FFTComplex *in, |
| ptrdiff_t stride) |
| { |
| const FFTComplex *exptab = s->exptab[0]; |
| FFTComplex tmp[5]; |
| FFTComplex tmp1[5]; |
| FFTComplex tmp2[5]; |
| int k; |
| |
| fft5(tmp, in, stride * 3); |
| fft5(tmp1, in + stride, stride * 3); |
| fft5(tmp2, in + 2 * stride, stride * 3); |
| |
| for (k = 0; k < 5; k++) { |
| FFTComplex t1, t2; |
| |
| CMUL(t1, tmp1[k], exptab[k]); |
| CMUL(t2, tmp2[k], exptab[2 * k]); |
| out[k].re = tmp[k].re + t1.re + t2.re; |
| out[k].im = tmp[k].im + t1.im + t2.im; |
| |
| CMUL(t1, tmp1[k], exptab[k + 5]); |
| CMUL(t2, tmp2[k], exptab[2 * (k + 5)]); |
| out[k + 5].re = tmp[k].re + t1.re + t2.re; |
| out[k + 5].im = tmp[k].im + t1.im + t2.im; |
| |
| CMUL(t1, tmp1[k], exptab[k + 10]); |
| CMUL(t2, tmp2[k], exptab[2 * k + 5]); |
| out[k + 10].re = tmp[k].re + t1.re + t2.re; |
| out[k + 10].im = tmp[k].im + t1.im + t2.im; |
| } |
| } |
| |
| /* |
| * FFT of the length 15 * (2^N) |
| */ |
| static void fft_calc(IMDCT15Context *s, FFTComplex *out, const FFTComplex *in, |
| int N, ptrdiff_t stride) |
| { |
| if (N) { |
| const FFTComplex *exptab = s->exptab[N]; |
| const int len2 = 15 * (1 << (N - 1)); |
| int k; |
| |
| fft_calc(s, out, in, N - 1, stride * 2); |
| fft_calc(s, out + len2, in + stride, N - 1, stride * 2); |
| |
| for (k = 0; k < len2; k++) { |
| FFTComplex t; |
| |
| CMUL(t, out[len2 + k], exptab[k]); |
| |
| out[len2 + k].re = out[k].re - t.re; |
| out[len2 + k].im = out[k].im - t.im; |
| |
| out[k].re += t.re; |
| out[k].im += t.im; |
| } |
| } else |
| fft15(s, out, in, stride); |
| } |
| |
| static void imdct15_half(IMDCT15Context *s, float *dst, const float *src, |
| ptrdiff_t stride, float scale) |
| { |
| FFTComplex *z = (FFTComplex *)dst; |
| const int len8 = s->len4 / 2; |
| const float *in1 = src; |
| const float *in2 = src + (s->len2 - 1) * stride; |
| int i; |
| |
| for (i = 0; i < s->len4; i++) { |
| FFTComplex tmp = { *in2, *in1 }; |
| CMUL(s->tmp[i], tmp, s->twiddle_exptab[i]); |
| in1 += 2 * stride; |
| in2 -= 2 * stride; |
| } |
| |
| fft_calc(s, z, s->tmp, s->fft_n, 1); |
| |
| for (i = 0; i < len8; i++) { |
| float r0, i0, r1, i1; |
| |
| CMUL3(r0, i1, z[len8 - i - 1].im, z[len8 - i - 1].re, s->twiddle_exptab[len8 - i - 1].im, s->twiddle_exptab[len8 - i - 1].re); |
| CMUL3(r1, i0, z[len8 + i].im, z[len8 + i].re, s->twiddle_exptab[len8 + i].im, s->twiddle_exptab[len8 + i].re); |
| z[len8 - i - 1].re = scale * r0; |
| z[len8 - i - 1].im = scale * i0; |
| z[len8 + i].re = scale * r1; |
| z[len8 + i].im = scale * i1; |
| } |
| } |
