diff options
Diffstat (limited to 'chromium/third_party/ffmpeg/libavcodec/opus_imdct.c')
| -rw-r--r-- | chromium/third_party/ffmpeg/libavcodec/opus_imdct.c | 272 |
1 files changed, 272 insertions, 0 deletions
diff --git a/chromium/third_party/ffmpeg/libavcodec/opus_imdct.c b/chromium/third_party/ffmpeg/libavcodec/opus_imdct.c new file mode 100644 index 00000000000..0a6fca994ec --- /dev/null +++ b/chromium/third_party/ffmpeg/libavcodec/opus_imdct.c @@ -0,0 +1,272 @@ +/* + * 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 "opus.h" +#include "opus_imdct.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_celt_imdct_uninit(CeltIMDCTContext **ps) +{ + CeltIMDCTContext *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 celt_imdct_half(CeltIMDCTContext *s, float *dst, const float *src, + ptrdiff_t stride, float scale); + +av_cold int ff_celt_imdct_init(CeltIMDCTContext **ps, int N) +{ + CeltIMDCTContext *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(len * 2 * sizeof(*s->tmp)); + if (!s->tmp) + goto fail; + + s->twiddle_exptab = av_malloc(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 = celt_imdct_half; + + if (ARCH_AARCH64) + ff_celt_imdct_init_aarch64(s); + + *ps = s; + + return 0; +fail: + ff_celt_imdct_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(CeltIMDCTContext *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(CeltIMDCTContext *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 celt_imdct_half(CeltIMDCTContext *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; + } +} |