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lavu/tx: add a 7-point FFT and (i)MDCT

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Lynne 2021-04-10 03:51:59 +02:00
parent 89da62f2fc
commit bd9ea917a3
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1 changed files with 116 additions and 10 deletions
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126
libavutil/tx_template.c
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@ -40,6 +40,7 @@ COSTABLE(32768);
COSTABLE(65536);
COSTABLE(131072);
DECLARE_ALIGNED(32, FFTComplex, TX_NAME(ff_cos_53))[4];
DECLARE_ALIGNED(32, FFTComplex, TX_NAME(ff_cos_7))[3];
static FFTSample * const cos_tabs[18] = {
NULL,
@ -103,9 +104,16 @@ static av_cold void ff_init_53_tabs(void)
TX_NAME(ff_cos_53)[3] = (FFTComplex){ RESCALE(cos(2 * M_PI / 10)), RESCALE(sin(2 * M_PI / 10)) };
}
static av_cold void ff_init_7_tabs(void)
{
TX_NAME(ff_cos_7)[0] = (FFTComplex){ RESCALE(cos(2 * M_PI / 7)), RESCALE(sin(2 * M_PI / 7)) };
TX_NAME(ff_cos_7)[1] = (FFTComplex){ RESCALE(sin(2 * M_PI / 28)), RESCALE(cos(2 * M_PI / 28)) };
TX_NAME(ff_cos_7)[2] = (FFTComplex){ RESCALE(cos(2 * M_PI / 14)), RESCALE(sin(2 * M_PI / 14)) };
}
static CosTabsInitOnce cos_tabs_init_once[] = {
{ ff_init_53_tabs, AV_ONCE_INIT },
{ NULL },
{ ff_init_7_tabs, AV_ONCE_INIT },
{ NULL },
{ NULL },
{ init_cos_tabs_16, AV_ONCE_INIT },
@ -204,6 +212,93 @@ DECL_FFT5(fft5_m1, 0, 6, 12, 3, 9)
DECL_FFT5(fft5_m2, 10, 1, 7, 13, 4)
DECL_FFT5(fft5_m3, 5, 11, 2, 8, 14)
static av_always_inline void fft7(FFTComplex *out, FFTComplex *in,
ptrdiff_t stride)
{
FFTComplex t[6], z[3];
const FFTComplex *tab = TX_NAME(ff_cos_7);
#ifdef TX_INT32
int64_t mtmp[12];
#endif
BF(t[1].re, t[0].re, in[1].re, in[6].re);
BF(t[1].im, t[0].im, in[1].im, in[6].im);
BF(t[3].re, t[2].re, in[2].re, in[5].re);
BF(t[3].im, t[2].im, in[2].im, in[5].im);
BF(t[5].re, t[4].re, in[3].re, in[4].re);
BF(t[5].im, t[4].im, in[3].im, in[4].im);
out[0*stride].re = in[0].re + t[0].re + t[2].re + t[4].re;
out[0*stride].im = in[0].im + t[0].im + t[2].im + t[4].im;
#ifdef TX_INT32 /* NOTE: it's possible to do this with 16 mults but 72 adds */
mtmp[ 0] = ((int64_t)tab[0].re)*t[0].re - ((int64_t)tab[2].re)*t[4].re;
mtmp[ 1] = ((int64_t)tab[0].re)*t[4].re - ((int64_t)tab[1].re)*t[0].re;
mtmp[ 2] = ((int64_t)tab[0].re)*t[2].re - ((int64_t)tab[2].re)*t[0].re;
mtmp[ 3] = ((int64_t)tab[0].re)*t[0].im - ((int64_t)tab[1].re)*t[2].im;
mtmp[ 4] = ((int64_t)tab[0].re)*t[4].im - ((int64_t)tab[1].re)*t[0].im;
mtmp[ 5] = ((int64_t)tab[0].re)*t[2].im - ((int64_t)tab[2].re)*t[0].im;
mtmp[ 6] = ((int64_t)tab[2].im)*t[1].im + ((int64_t)tab[1].im)*t[5].im;
mtmp[ 7] = ((int64_t)tab[0].im)*t[5].im + ((int64_t)tab[2].im)*t[3].im;
mtmp[ 8] = ((int64_t)tab[2].im)*t[5].im + ((int64_t)tab[1].im)*t[3].im;
mtmp[ 9] = ((int64_t)tab[0].im)*t[1].re + ((int64_t)tab[1].im)*t[3].re;
mtmp[10] = ((int64_t)tab[2].im)*t[3].re + ((int64_t)tab[0].im)*t[5].re;
mtmp[11] = ((int64_t)tab[2].im)*t[1].re + ((int64_t)tab[1].im)*t[5].re;
z[0].re = (int32_t)(mtmp[ 0] - ((int64_t)tab[1].re)*t[2].re + 0x40000000 >> 31);
z[1].re = (int32_t)(mtmp[ 1] - ((int64_t)tab[2].re)*t[2].re + 0x40000000 >> 31);
z[2].re = (int32_t)(mtmp[ 2] - ((int64_t)tab[1].re)*t[4].re + 0x40000000 >> 31);
z[0].im = (int32_t)(mtmp[ 3] - ((int64_t)tab[2].re)*t[4].im + 0x40000000 >> 31);
z[1].im = (int32_t)(mtmp[ 4] - ((int64_t)tab[2].re)*t[2].im + 0x40000000 >> 31);
z[2].im = (int32_t)(mtmp[ 5] - ((int64_t)tab[1].re)*t[4].im + 0x40000000 >> 31);
t[0].re = (int32_t)(mtmp[ 6] - ((int64_t)tab[0].im)*t[3].im + 0x40000000 >> 31);
t[2].re = (int32_t)(mtmp[ 7] - ((int64_t)tab[1].im)*t[1].im + 0x40000000 >> 31);
t[4].re = (int32_t)(mtmp[ 8] + ((int64_t)tab[0].im)*t[1].im + 0x40000000 >> 31);
t[0].im = (int32_t)(mtmp[ 9] + ((int64_t)tab[2].im)*t[5].re + 0x40000000 >> 31);
t[2].im = (int32_t)(mtmp[10] - ((int64_t)tab[1].im)*t[1].re + 0x40000000 >> 31);
t[4].im = (int32_t)(mtmp[11] - ((int64_t)tab[0].im)*t[3].re + 0x40000000 >> 31);
#else
z[0].re = tab[0].re*t[0].re - tab[2].re*t[4].re - tab[1].re*t[2].re;
z[1].re = tab[0].re*t[4].re - tab[1].re*t[0].re - tab[2].re*t[2].re;
z[2].re = tab[0].re*t[2].re - tab[2].re*t[0].re - tab[1].re*t[4].re;
z[0].im = tab[0].re*t[0].im - tab[1].re*t[2].im - tab[2].re*t[4].im;
z[1].im = tab[0].re*t[4].im - tab[1].re*t[0].im - tab[2].re*t[2].im;
z[2].im = tab[0].re*t[2].im - tab[2].re*t[0].im - tab[1].re*t[4].im;
/* It's possible to do t[4].re and t[0].im with 2 multiplies only by
* multiplying the sum of all with the average of the twiddles */
t[0].re = tab[2].im*t[1].im + tab[1].im*t[5].im - tab[0].im*t[3].im;
t[2].re = tab[0].im*t[5].im + tab[2].im*t[3].im - tab[1].im*t[1].im;
t[4].re = tab[2].im*t[5].im + tab[1].im*t[3].im + tab[0].im*t[1].im;
t[0].im = tab[0].im*t[1].re + tab[1].im*t[3].re + tab[2].im*t[5].re;
t[2].im = tab[2].im*t[3].re + tab[0].im*t[5].re - tab[1].im*t[1].re;
t[4].im = tab[2].im*t[1].re + tab[1].im*t[5].re - tab[0].im*t[3].re;
#endif
BF(t[1].re, z[0].re, z[0].re, t[4].re);
BF(t[3].re, z[1].re, z[1].re, t[2].re);
BF(t[5].re, z[2].re, z[2].re, t[0].re);
BF(t[1].im, z[0].im, z[0].im, t[0].im);
BF(t[3].im, z[1].im, z[1].im, t[2].im);
BF(t[5].im, z[2].im, z[2].im, t[4].im);
out[1*stride].re = in[0].re + z[0].re;
out[1*stride].im = in[0].im + t[1].im;
out[2*stride].re = in[0].re + t[3].re;
out[2*stride].im = in[0].im + z[1].im;
out[3*stride].re = in[0].re + z[2].re;
out[3*stride].im = in[0].im + t[5].im;
out[4*stride].re = in[0].re + t[5].re;
out[4*stride].im = in[0].im + z[2].im;
out[5*stride].re = in[0].re + z[1].re;
out[5*stride].im = in[0].im + t[3].im;
out[6*stride].re = in[0].re + t[1].re;
out[6*stride].im = in[0].im + z[0].im;
}
static av_always_inline void fft15(FFTComplex *out, FFTComplex *in,
ptrdiff_t stride)
{
@ -376,6 +471,7 @@ static void compound_fft_##N##xM(AVTXContext *s, void *_out, \
DECL_COMP_FFT(3)
DECL_COMP_FFT(5)
DECL_COMP_FFT(7)
DECL_COMP_FFT(15)
static void split_radix_fft(AVTXContext *s, void *_out, void *_in,
@ -473,6 +569,7 @@ static void compound_imdct_##N##xM(AVTXContext *s, void *_dst, void *_src, \
DECL_COMP_IMDCT(3)
DECL_COMP_IMDCT(5)
DECL_COMP_IMDCT(7)
DECL_COMP_IMDCT(15)
#define DECL_COMP_MDCT(N) \
@ -521,6 +618,7 @@ static void compound_mdct_##N##xM(AVTXContext *s, void *_dst, void *_src, \
DECL_COMP_MDCT(3)
DECL_COMP_MDCT(5)
DECL_COMP_MDCT(7)
DECL_COMP_MDCT(15)
static void monolithic_imdct(AVTXContext *s, void *_dst, void *_src,
@ -675,6 +773,7 @@ int TX_NAME(ff_tx_init_mdct_fft)(AVTXContext *s, av_tx_fn *tx,
SRC /= FACTOR; \
}
CHECK_FACTOR(n, 15, len)
CHECK_FACTOR(n, 7, len)
CHECK_FACTOR(n, 5, len)
CHECK_FACTOR(n, 3, len)
#undef CHECK_FACTOR
@ -714,22 +813,29 @@ int TX_NAME(ff_tx_init_mdct_fft)(AVTXContext *s, av_tx_fn *tx,
return err;
if (!(s->tmp = av_malloc(n*m*sizeof(*s->tmp))))
return AVERROR(ENOMEM);
*tx = n == 3 ? compound_fft_3xM :
n == 5 ? compound_fft_5xM :
compound_fft_15xM;
if (is_mdct)
*tx = n == 3 ? inv ? compound_imdct_3xM : compound_mdct_3xM :
n == 5 ? inv ? compound_imdct_5xM : compound_mdct_5xM :
inv ? compound_imdct_15xM : compound_mdct_15xM;
if (!(m & (m - 1))) {
*tx = n == 3 ? compound_fft_3xM :
n == 5 ? compound_fft_5xM :
n == 7 ? compound_fft_7xM :
compound_fft_15xM;
if (is_mdct)
*tx = n == 3 ? inv ? compound_imdct_3xM : compound_mdct_3xM :
n == 5 ? inv ? compound_imdct_5xM : compound_mdct_5xM :
n == 7 ? inv ? compound_imdct_7xM : compound_mdct_7xM :
inv ? compound_imdct_15xM : compound_mdct_15xM;
}
} else { /* Direct transform case */
*tx = split_radix_fft;
if (is_mdct)
*tx = inv ? monolithic_imdct : monolithic_mdct;
}
if (n != 1)
if (n == 3 || n == 5 || n == 15)
init_cos_tabs(0);
if (m != 1) {
else if (n == 7)
init_cos_tabs(1);
if (m != 1 && !(m & (m - 1))) {
if ((err = ff_tx_gen_ptwo_revtab(s, n == 1 && !is_mdct && !(flags & AV_TX_INPLACE))))
return err;
if (flags & AV_TX_INPLACE) {