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-rw-r--r--libavcodec/imdct15.c302
-rw-r--r--libavcodec/imdct15.h9
2 files changed, 162 insertions, 149 deletions
diff --git a/libavcodec/imdct15.c b/libavcodec/imdct15.c
index 7481c026cf..a6d4249636 100644
--- a/libavcodec/imdct15.c
+++ b/libavcodec/imdct15.c
@@ -1,5 +1,6 @@
/*
* Copyright (c) 2013-2014 Mozilla Corporation
+ * Copyright (c) 2017 Rostislav Pehlivanov <atomnuker@gmail.com>
*
* This file is part of FFmpeg.
*
@@ -32,12 +33,7 @@
#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) \
@@ -48,37 +44,18 @@ do { \
#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]);
+ ff_fft_end(&s->ptwo_fft);
+ av_freep(&s->pfa_prereindex);
+ av_freep(&s->pfa_postreindex);
av_freep(&s->twiddle_exptab);
-
av_freep(&s->tmp);
av_freep(ps);
@@ -87,14 +64,46 @@ av_cold void ff_imdct15_uninit(IMDCT15Context **ps)
static void imdct15_half(IMDCT15Context *s, float *dst, const float *src,
ptrdiff_t stride, float scale);
+static inline int init_pfa_reindex_tabs(IMDCT15Context *s)
+{
+ int i, j;
+ const int b_ptwo = s->ptwo_fft.nbits; /* Bits for the power of two FFTs */
+ const int l_ptwo = 1 << b_ptwo; /* Total length for the power of two FFTs */
+ const int inv_1 = l_ptwo << ((4 - b_ptwo) & 3); /* (2^b_ptwo)^-1 mod 15 */
+ const int inv_2 = 0xeeeeeeef & ((1U << b_ptwo) - 1); /* 15^-1 mod 2^b_ptwo */
+
+ s->pfa_prereindex = av_malloc(15 * l_ptwo * sizeof(*s->pfa_prereindex));
+ if (!s->pfa_prereindex)
+ return 1;
+
+ s->pfa_postreindex = av_malloc(15 * l_ptwo * sizeof(*s->pfa_postreindex));
+ if (!s->pfa_postreindex)
+ return 1;
+
+ /* Pre/Post-reindex */
+ for (i = 0; i < l_ptwo; i++) {
+ for (j = 0; j < 15; j++) {
+ const int q_pre = ((l_ptwo * j)/15 + i) >> b_ptwo;
+ const int q_post = (((j*inv_1)/15) + (i*inv_2)) >> b_ptwo;
+ const int k_pre = 15*i + (j - q_pre*15)*l_ptwo;
+ const int k_post = i*inv_2*15 + j*inv_1 - 15*q_post*l_ptwo;
+ s->pfa_prereindex[i*15 + j] = k_pre;
+ s->pfa_postreindex[k_post] = l_ptwo*j + i;
+ }
+ }
+
+ return 0;
+}
+
av_cold int ff_imdct15_init(IMDCT15Context **ps, int N)
{
IMDCT15Context *s;
int len2 = 15 * (1 << N);
int len = 2 * len2;
- int i, j;
+ int i;
- if (len2 > CELT_MAX_FRAME_SIZE || len2 < CELT_MIN_IMDCT_SIZE)
+ /* Tested and verified to work on everything in between */
+ if ((N < 2) || (N > 13))
return AVERROR(EINVAL);
s = av_mallocz(sizeof(*s));
@@ -104,6 +113,13 @@ av_cold int ff_imdct15_init(IMDCT15Context **ps, int N)
s->fft_n = N - 1;
s->len4 = len2 / 2;
s->len2 = len2;
+ s->imdct_half = imdct15_half;
+
+ if (ff_fft_init(&s->ptwo_fft, N - 1, 1) < 0)
+ goto fail;
+
+ if (init_pfa_reindex_tabs(s))
+ goto fail;
s->tmp = av_malloc_array(len, 2 * sizeof(*s->tmp));
if (!s->tmp)
@@ -114,27 +130,30 @@ av_cold int ff_imdct15_init(IMDCT15Context **ps, int N)
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);
+ s->twiddle_exptab[i].re = cos(2 * M_PI * (i + 0.125f + s->len4) / len);
+ s->twiddle_exptab[i].im = sin(2 * M_PI * (i + 0.125f + 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);
+ /* 15-point FFT exptab */
+ for (i = 0; i < 19; i++) {
+ if (i < 15) {
+ double theta = (2.0f * M_PI * i) / 15.0f;
+ s->exptab[i].re = cos(theta);
+ s->exptab[i].im = sin(theta);
+ } else { /* Wrap around to simplify fft15 */
+ s->exptab[i] = s->exptab[i - 15];
}
}
- // wrap around to simplify fft15
- for (j = 15; j < 19; j++)
- s->exptab[0][j] = s->exptab[0][j - 15];
+ /* 5-point FFT exptab */
+ s->exptab[19].re = cos(2.0f * M_PI / 5.0f);
+ s->exptab[19].im = sin(2.0f * M_PI / 5.0f);
+ s->exptab[20].re = cos(1.0f * M_PI / 5.0f);
+ s->exptab[20].im = sin(1.0f * M_PI / 5.0f);
- s->imdct_half = imdct15_half;
+ /* Invert the phase for an inverse transform, do nothing for a forward transform */
+ s->exptab[19].im *= -1;
+ s->exptab[20].im *= -1;
*ps = s;
@@ -145,127 +164,116 @@ fail:
return AVERROR(ENOMEM);
}
-static void fft5(FFTComplex *out, const FFTComplex *in, ptrdiff_t stride)
+/* Stride is hardcoded to 3 */
+static inline void fft5(const FFTComplex exptab[2], FFTComplex *out,
+ const FFTComplex *in)
{
- // [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;
+ FFTComplex z0[4], t[6];
+
+ t[0].re = in[3].re + in[12].re;
+ t[0].im = in[3].im + in[12].im;
+ t[1].im = in[3].re - in[12].re;
+ t[1].re = in[3].im - in[12].im;
+ t[2].re = in[6].re + in[ 9].re;
+ t[2].im = in[6].im + in[ 9].im;
+ t[3].im = in[6].re - in[ 9].re;
+ t[3].re = in[6].im - in[ 9].im;
+
+ out[0].re = in[0].re + in[3].re + in[6].re + in[9].re + in[12].re;
+ out[0].im = in[0].im + in[3].im + in[6].im + in[9].im + in[12].im;
+
+ t[4].re = exptab[0].re * t[2].re - exptab[1].re * t[0].re;
+ t[4].im = exptab[0].re * t[2].im - exptab[1].re * t[0].im;
+ t[0].re = exptab[0].re * t[0].re - exptab[1].re * t[2].re;
+ t[0].im = exptab[0].re * t[0].im - exptab[1].re * t[2].im;
+ t[5].re = exptab[0].im * t[3].re - exptab[1].im * t[1].re;
+ t[5].im = exptab[0].im * t[3].im - exptab[1].im * t[1].im;
+ t[1].re = exptab[0].im * t[1].re + exptab[1].im * t[3].re;
+ t[1].im = exptab[0].im * t[1].im + exptab[1].im * t[3].im;
+
+ z0[0].re = t[0].re - t[1].re;
+ z0[0].im = t[0].im - t[1].im;
+ z0[1].re = t[4].re + t[5].re;
+ z0[1].im = t[4].im + t[5].im;
+
+ z0[2].re = t[4].re - t[5].re;
+ z0[2].im = t[4].im - t[5].im;
+ z0[3].re = t[0].re + t[1].re;
+ z0[3].im = t[0].im + t[1].im;
+
+ out[1].re = in[0].re + z0[3].re;
+ out[1].im = in[0].im + z0[0].im;
+ out[2].re = in[0].re + z0[2].re;
+ out[2].im = in[0].im + z0[1].im;
+ out[3].re = in[0].re + z0[1].re;
+ out[3].im = in[0].im + z0[2].im;
+ out[4].re = in[0].re + z0[0].re;
+ out[4].im = in[0].im + z0[3].im;
}
-static void fft15(IMDCT15Context *s, FFTComplex *out, const FFTComplex *in,
- ptrdiff_t stride)
+static inline void fft15(const FFTComplex exptab[22], FFTComplex *out,
+ const FFTComplex *in, size_t stride)
{
- const FFTComplex *exptab = s->exptab[0];
- FFTComplex tmp[5];
- FFTComplex tmp1[5];
- FFTComplex tmp2[5];
int k;
+ FFTComplex tmp1[5], tmp2[5], tmp3[5];
- fft5(tmp, in, stride * 3);
- fft5(tmp1, in + stride, stride * 3);
- fft5(tmp2, in + 2 * stride, stride * 3);
+ fft5(exptab + 19, tmp1, in + 0);
+ fft5(exptab + 19, tmp2, in + 1);
+ fft5(exptab + 19, tmp3, in + 2);
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;
+ FFTComplex t[2];
+
+ CMUL(t[0], tmp2[k], exptab[k]);
+ CMUL(t[1], tmp3[k], exptab[2 * k]);
+ out[stride*k].re = tmp1[k].re + t[0].re + t[1].re;
+ out[stride*k].im = tmp1[k].im + t[0].im + t[1].im;
+
+ CMUL(t[0], tmp2[k], exptab[k + 5]);
+ CMUL(t[1], tmp3[k], exptab[2 * (k + 5)]);
+ out[stride*(k + 5)].re = tmp1[k].re + t[0].re + t[1].re;
+ out[stride*(k + 5)].im = tmp1[k].im + t[0].im + t[1].im;
+
+ CMUL(t[0], tmp2[k], exptab[k + 10]);
+ CMUL(t[1], tmp3[k], exptab[2 * k + 5]);
+ out[stride*(k + 10)].re = tmp1[k].re + t[0].re + t[1].re;
+ out[stride*(k + 10)].im = tmp1[k].im + t[0].im + t[1].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 fft15in[15];
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;
+ int i, j, len8 = s->len4 >> 1, l_ptwo = 1 << s->ptwo_fft.nbits;
+ const float *in1 = src, *in2 = src + (s->len2 - 1) * stride;
+
+ /* Reindex input, putting it into a buffer and doing an Nx15 FFT */
+ for (i = 0; i < l_ptwo; i++) {
+ for (j = 0; j < 15; j++) {
+ const int k = s->pfa_prereindex[i*15 + j];
+ FFTComplex tmp = { *(in2 - 2*k*stride), *(in1 + 2*k*stride) };
+ CMUL(fft15in[j], tmp, s->twiddle_exptab[k]);
+ }
+ fft15(s->exptab, s->tmp + s->ptwo_fft.revtab[i], fft15in, l_ptwo);
}
- fft_calc(s, z, s->tmp, s->fft_n, 1);
+ /* Then a 15xN FFT (where N is a power of two) */
+ for (i = 0; i < 15; i++)
+ s->ptwo_fft.fft_calc(&s->ptwo_fft, s->tmp + l_ptwo*i);
+ /* Reindex again, apply twiddles and output */
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;
+ float re0, im0, re1, im1;
+ const int i0 = len8 + i, i1 = len8 - i - 1;
+ const int s0 = s->pfa_postreindex[i0], s1 = s->pfa_postreindex[i1];
+
+ CMUL3(re0, im1, s->tmp[s1].im, s->tmp[s1].re, s->twiddle_exptab[i1].im, s->twiddle_exptab[i1].re);
+ CMUL3(re1, im0, s->tmp[s0].im, s->tmp[s0].re, s->twiddle_exptab[i0].im, s->twiddle_exptab[i0].re);
+ z[i1].re = scale * re0;
+ z[i1].im = scale * im0;
+ z[i0].re = scale * re1;
+ z[i0].im = scale * im1;
}
}
diff --git a/libavcodec/imdct15.h b/libavcodec/imdct15.h
index 7a58aac8b3..a31f11e359 100644
--- a/libavcodec/imdct15.h
+++ b/libavcodec/imdct15.h
@@ -21,18 +21,23 @@
#include <stddef.h>
-#include "avfft.h"
+#include "fft.h"
typedef struct IMDCT15Context {
int fft_n;
int len2;
int len4;
+ int *pfa_prereindex;
+ int *pfa_postreindex;
+
+ FFTContext ptwo_fft;
FFTComplex *tmp;
FFTComplex *twiddle_exptab;
- FFTComplex *exptab[6];
+ /* 0 - 18: fft15 twiddles, 19 - 20: fft5 twiddles */
+ FFTComplex exptab[21];
/**
* Calculate the middle half of the iMDCT
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-10 11:11:16 +0000