Head

GCC Code Coverage Report

Directory:	../../../ffmpeg/		Exec	Total	Coverage
File:	src/libavcodec/mdct15.c	Lines:	145	179	81.0 %
Date:	2020-01-28 04:56:05	Branches:	34	56	60.7 %


/*
 * Copyright (c) 2013-2014 Mozilla Corporation
 * Copyright (c) 2017 Rostislav Pehlivanov <atomnuker@gmail.com>
 *
 * 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 "mdct15.h"

#define FFT_FLOAT 1
#include "fft-internal.h"

#define CMUL3(c, a, b) CMUL((c).re, (c).im, (a).re, (a).im, (b).re, (b).im)

av_cold void ff_mdct15_uninit(MDCT15Context **ps)
{
    MDCT15Context *s = *ps;

    if (!s)
        return;

    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);
}

static inline int init_pfa_reindex_tabs(MDCT15Context *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_array(15 * l_ptwo, sizeof(*s->pfa_prereindex));
    if (!s->pfa_prereindex)
        return 1;

    s->pfa_postreindex = av_malloc_array(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)*(1 << b_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 << 1;
            s->pfa_postreindex[k_post] = l_ptwo*j + i;
        }
    }

    return 0;
}

/* Stride is hardcoded to 3 */
static inline void fft5(FFTComplex *out, FFTComplex *in, FFTComplex exptab[2])
{
    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_c(FFTComplex *out, FFTComplex *in, FFTComplex *exptab, ptrdiff_t stride)
{
    int k;
    FFTComplex tmp1[5], tmp2[5], tmp3[5];

    fft5(tmp1, in + 0, exptab + 19);
    fft5(tmp2, in + 1, exptab + 19);
    fft5(tmp3, in + 2, exptab + 19);

    for (k = 0; k < 5; k++) {
        FFTComplex t[2];

        CMUL3(t[0], tmp2[k], exptab[k]);
        CMUL3(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;

        CMUL3(t[0], tmp2[k], exptab[k + 5]);
        CMUL3(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;

        CMUL3(t[0], tmp2[k], exptab[k + 10]);
        CMUL3(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;
    }
}

static void mdct15(MDCT15Context *s, float *dst, const float *src, ptrdiff_t stride)
{
    int i, j;
    const int len4 = s->len4, len3 = len4 * 3, len8 = len4 >> 1;
    const int l_ptwo = 1 << s->ptwo_fft.nbits;
    FFTComplex fft15in[15];

    /* Folding and pre-reindexing */
    for (i = 0; i < l_ptwo; i++) {
        for (j = 0; j < 15; j++) {
            const int k = s->pfa_prereindex[i*15 + j];
            FFTComplex tmp, exp = s->twiddle_exptab[k >> 1];
            if (k < len4) {
                tmp.re = -src[ len4 + k] + src[1*len4 - 1 - k];
                tmp.im = -src[ len3 + k] - src[1*len3 - 1 - k];
            } else {
                tmp.re = -src[ len4 + k] - src[5*len4 - 1 - k];
                tmp.im =  src[-len4 + k] - src[1*len3 - 1 - k];
            }
            CMUL(fft15in[j].im, fft15in[j].re, tmp.re, tmp.im, exp.re, exp.im);
        }
        s->fft15(s->tmp + s->ptwo_fft.revtab[i], fft15in, s->exptab, l_ptwo);
    }

    /* 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++) {
        const int i0 = len8 + i, i1 = len8 - i - 1;
        const int s0 = s->pfa_postreindex[i0], s1 = s->pfa_postreindex[i1];

        CMUL(dst[2*i1*stride + stride], dst[2*i0*stride], s->tmp[s0].re, s->tmp[s0].im,
             s->twiddle_exptab[i0].im, s->twiddle_exptab[i0].re);
        CMUL(dst[2*i0*stride + stride], dst[2*i1*stride], s->tmp[s1].re, s->tmp[s1].im,
             s->twiddle_exptab[i1].im, s->twiddle_exptab[i1].re);
    }
}

static void imdct15_half(MDCT15Context *s, float *dst, const float *src,
                         ptrdiff_t stride)
{
    FFTComplex fft15in[15];
    FFTComplex *z = (FFTComplex *)dst;
    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[-k*stride], in1[k*stride] };
            CMUL3(fft15in[j], tmp, s->twiddle_exptab[k >> 1]);
        }
        s->fft15(s->tmp + s->ptwo_fft.revtab[i], fft15in, s->exptab, l_ptwo);
    }

    /* 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 */
    s->postreindex(z, s->tmp, s->twiddle_exptab, s->pfa_postreindex, len8);
}

static void postrotate_c(FFTComplex *out, FFTComplex *in, FFTComplex *exp,
                         int *lut, ptrdiff_t len8)
{
    int i;

    /* Reindex again, apply twiddles and output */
    for (i = 0; i < len8; i++) {
        const int i0 = len8 + i, i1 = len8 - i - 1;
        const int s0 = lut[i0], s1 = lut[i1];

        CMUL(out[i1].re, out[i0].im, in[s1].im, in[s1].re, exp[i1].im, exp[i1].re);
        CMUL(out[i0].re, out[i1].im, in[s0].im, in[s0].re, exp[i0].im, exp[i0].re);
    }
}

av_cold int ff_mdct15_init(MDCT15Context **ps, int inverse, int N, double scale)
{
    MDCT15Context *s;
    double alpha, theta;
    int len2 = 15 * (1 << N);
    int len  = 2 * len2;
    int i;

    /* Tested and verified to work on everything in between */
    if ((N < 2) || (N > 13))
        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->inverse     = inverse;
    s->fft15       = fft15_c;
    s->mdct        = mdct15;
    s->imdct_half  = imdct15_half;
    s->postreindex = postrotate_c;

    if (ff_fft_init(&s->ptwo_fft, N - 1, s->inverse) < 0)
        goto fail;

    if (init_pfa_reindex_tabs(s))
        goto fail;

    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;

    theta = 0.125f + (scale < 0 ? s->len4 : 0);
    scale = sqrt(fabs(scale));
    for (i = 0; i < s->len4; i++) {
        alpha = 2 * M_PI * (i + theta) / len;
        s->twiddle_exptab[i].re = cosf(alpha) * scale;
        s->twiddle_exptab[i].im = sinf(alpha) * scale;
    }

    /* 15-point FFT exptab */
    for (i = 0; i < 19; i++) {
        if (i < 15) {
            double theta = (2.0f * M_PI * i) / 15.0f;
            if (!s->inverse)
                theta *= -1;
            s->exptab[i].re = cosf(theta);
            s->exptab[i].im = sinf(theta);
        } else { /* Wrap around to simplify fft15 */
            s->exptab[i] = s->exptab[i - 15];
        }
    }

    /* 5-point FFT exptab */
    s->exptab[19].re = cosf(2.0f * M_PI / 5.0f);
    s->exptab[19].im = sinf(2.0f * M_PI / 5.0f);
    s->exptab[20].re = cosf(1.0f * M_PI / 5.0f);
    s->exptab[20].im = sinf(1.0f * M_PI / 5.0f);

    /* Invert the phase for an inverse transform, do nothing for a forward transform */
    if (s->inverse) {
        s->exptab[19].im *= -1;
        s->exptab[20].im *= -1;
    }

    if (ARCH_X86)
        ff_mdct15_init_x86(s);

    *ps = s;

    return 0;

fail:
    ff_mdct15_uninit(&s);
    return AVERROR(ENOMEM);
}


Generated by: GCOVR (Version 4.1)

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.
16			*
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 = (((jinv_1)/15) + (iinv_2)) >> b_ptwo;
81		231900	const int k_pre = 15i + (j - q_pre15)*(1 << b_ptwo);
82		231900	const int k_post = iinv_215 + jinv_1 - 15q_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[2i1stride + stride], dst[2i0stride], s->tmp[s0].re, s->tmp[s0].im,
200			s->twiddle_exptab[i0].im, s->twiddle_exptab[i0].re);
201			CMUL(dst[2i0stride + stride], dst[2i1stride], 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[-kstride], in1[kstride] };
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			}