diff mbox series

[FFmpeg-devel,04/11] lavu/tx: add a 9-point FFT and (i)MDCT

Message ID MYfnDm_--3-2@lynne.ee
State Accepted
Commit 8c55c8258331377ffcc6fe74e0d80b3ab0966d11
Headers show
Series lavu/tx: FFT improvements, additions and assembly
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Commit Message

Lynne April 19, 2021, 8:22 p.m. UTC
Patch attached.
Subject: [PATCH 04/11] lavu/tx: add a 9-point FFT and (i)MDCT

---
 libavutil/tx_template.c | 144 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 143 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/libavutil/tx_template.c b/libavutil/tx_template.c
index 2946c039be..b3532c1c5e 100644
--- a/libavutil/tx_template.c
+++ b/libavutil/tx_template.c
@@ -41,6 +41,7 @@  COSTABLE(65536);
 COSTABLE(131072);
 DECLARE_ALIGNED(32, FFTComplex, TX_NAME(ff_cos_53))[4];
 DECLARE_ALIGNED(32, FFTComplex, TX_NAME(ff_cos_7))[3];
+DECLARE_ALIGNED(32, FFTComplex, TX_NAME(ff_cos_9))[4];
 
 static FFTSample * const cos_tabs[18] = {
     NULL,
@@ -111,10 +112,19 @@  static av_cold void ff_init_7_tabs(void)
     TX_NAME(ff_cos_7)[2] = (FFTComplex){ RESCALE(cos(2 * M_PI / 14)), RESCALE(sin(2 * M_PI / 14)) };
 }
 
+static av_cold void ff_init_9_tabs(void)
+{
+    TX_NAME(ff_cos_9)[0] = (FFTComplex){ RESCALE(cos(2 * M_PI /  3)), RESCALE( sin(2 * M_PI /  3)) };
+    TX_NAME(ff_cos_9)[1] = (FFTComplex){ RESCALE(cos(2 * M_PI /  9)), RESCALE( sin(2 * M_PI /  9)) };
+    TX_NAME(ff_cos_9)[2] = (FFTComplex){ RESCALE(cos(2 * M_PI / 36)), RESCALE( sin(2 * M_PI / 36)) };
+    TX_NAME(ff_cos_9)[3] = (FFTComplex){ TX_NAME(ff_cos_9)[1].re + TX_NAME(ff_cos_9)[2].im,
+                                         TX_NAME(ff_cos_9)[1].im - TX_NAME(ff_cos_9)[2].re };
+}
+
 static CosTabsInitOnce cos_tabs_init_once[] = {
     { ff_init_53_tabs, AV_ONCE_INIT },
     { ff_init_7_tabs, AV_ONCE_INIT },
-    { NULL },
+    { ff_init_9_tabs, AV_ONCE_INIT },
     { NULL },
     { init_cos_tabs_16, AV_ONCE_INIT },
     { init_cos_tabs_32, AV_ONCE_INIT },
@@ -299,6 +309,130 @@  static av_always_inline void fft7(FFTComplex *out, FFTComplex *in,
     out[6*stride].im = in[0].im + z[0].im;
 }
 
+static av_always_inline void fft9(FFTComplex *out, FFTComplex *in,
+                                  ptrdiff_t stride)
+{
+    const FFTComplex *tab = TX_NAME(ff_cos_9);
+    FFTComplex t[16], w[4], x[5], y[5], z[2];
+#ifdef TX_INT32
+    int64_t mtmp[12];
+#endif
+
+    BF(t[1].re, t[0].re, in[1].re, in[8].re);
+    BF(t[1].im, t[0].im, in[1].im, in[8].im);
+    BF(t[3].re, t[2].re, in[2].re, in[7].re);
+    BF(t[3].im, t[2].im, in[2].im, in[7].im);
+    BF(t[5].re, t[4].re, in[3].re, in[6].re);
+    BF(t[5].im, t[4].im, in[3].im, in[6].im);
+    BF(t[7].re, t[6].re, in[4].re, in[5].re);
+    BF(t[7].im, t[6].im, in[4].im, in[5].im);
+
+    w[0].re = t[0].re - t[6].re;
+    w[0].im = t[0].im - t[6].im;
+    w[1].re = t[2].re - t[6].re;
+    w[1].im = t[2].im - t[6].im;
+    w[2].re = t[1].re - t[7].re;
+    w[2].im = t[1].im - t[7].im;
+    w[3].re = t[3].re + t[7].re;
+    w[3].im = t[3].im + t[7].im;
+
+    z[0].re = in[0].re + t[4].re;
+    z[0].im = in[0].im + t[4].im;
+
+    z[1].re = t[0].re + t[2].re + t[6].re;
+    z[1].im = t[0].im + t[2].im + t[6].im;
+
+    out[0*stride].re = z[0].re + z[1].re;
+    out[0*stride].im = z[0].im + z[1].im;
+
+#ifdef TX_INT32
+    mtmp[0] = t[1].re - t[3].re + t[7].re;
+    mtmp[1] = t[1].im - t[3].im + t[7].im;
+
+    y[3].re = (int32_t)(((int64_t)tab[0].im)*mtmp[0] + 0x40000000 >> 31);
+    y[3].im = (int32_t)(((int64_t)tab[0].im)*mtmp[1] + 0x40000000 >> 31);
+
+    mtmp[0] = (int32_t)(((int64_t)tab[0].re)*z[1].re + 0x40000000 >> 31);
+    mtmp[1] = (int32_t)(((int64_t)tab[0].re)*z[1].im + 0x40000000 >> 31);
+    mtmp[2] = (int32_t)(((int64_t)tab[0].re)*t[4].re + 0x40000000 >> 31);
+    mtmp[3] = (int32_t)(((int64_t)tab[0].re)*t[4].im + 0x40000000 >> 31);
+
+    x[3].re = z[0].re  + (int32_t)mtmp[0];
+    x[3].im = z[0].im  + (int32_t)mtmp[1];
+    z[0].re = in[0].re + (int32_t)mtmp[2];
+    z[0].im = in[0].im + (int32_t)mtmp[3];
+
+    mtmp[0] = ((int64_t)tab[1].re)*w[0].re;
+    mtmp[1] = ((int64_t)tab[1].re)*w[0].im;
+    mtmp[2] = ((int64_t)tab[2].im)*w[0].re;
+    mtmp[3] = ((int64_t)tab[2].im)*w[0].im;
+    mtmp[4] = ((int64_t)tab[1].im)*w[2].re;
+    mtmp[5] = ((int64_t)tab[1].im)*w[2].im;
+    mtmp[6] = ((int64_t)tab[2].re)*w[2].re;
+    mtmp[7] = ((int64_t)tab[2].re)*w[2].im;
+
+    x[1].re = (int32_t)(mtmp[0] + ((int64_t)tab[2].im)*w[1].re + 0x40000000 >> 31);
+    x[1].im = (int32_t)(mtmp[1] + ((int64_t)tab[2].im)*w[1].im + 0x40000000 >> 31);
+    x[2].re = (int32_t)(mtmp[2] - ((int64_t)tab[3].re)*w[1].re + 0x40000000 >> 31);
+    x[2].im = (int32_t)(mtmp[3] - ((int64_t)tab[3].re)*w[1].im + 0x40000000 >> 31);
+    y[1].re = (int32_t)(mtmp[4] + ((int64_t)tab[2].re)*w[3].re + 0x40000000 >> 31);
+    y[1].im = (int32_t)(mtmp[5] + ((int64_t)tab[2].re)*w[3].im + 0x40000000 >> 31);
+    y[2].re = (int32_t)(mtmp[6] - ((int64_t)tab[3].im)*w[3].re + 0x40000000 >> 31);
+    y[2].im = (int32_t)(mtmp[7] - ((int64_t)tab[3].im)*w[3].im + 0x40000000 >> 31);
+
+    y[0].re = (int32_t)(((int64_t)tab[0].im)*t[5].re + 0x40000000 >> 31);
+    y[0].im = (int32_t)(((int64_t)tab[0].im)*t[5].im + 0x40000000 >> 31);
+
+#else
+    y[3].re = tab[0].im*(t[1].re - t[3].re + t[7].re);
+    y[3].im = tab[0].im*(t[1].im - t[3].im + t[7].im);
+
+    x[3].re = z[0].re  + tab[0].re*z[1].re;
+    x[3].im = z[0].im  + tab[0].re*z[1].im;
+    z[0].re = in[0].re + tab[0].re*t[4].re;
+    z[0].im = in[0].im + tab[0].re*t[4].im;
+
+    x[1].re = tab[1].re*w[0].re + tab[2].im*w[1].re;
+    x[1].im = tab[1].re*w[0].im + tab[2].im*w[1].im;
+    x[2].re = tab[2].im*w[0].re - tab[3].re*w[1].re;
+    x[2].im = tab[2].im*w[0].im - tab[3].re*w[1].im;
+    y[1].re = tab[1].im*w[2].re + tab[2].re*w[3].re;
+    y[1].im = tab[1].im*w[2].im + tab[2].re*w[3].im;
+    y[2].re = tab[2].re*w[2].re - tab[3].im*w[3].re;
+    y[2].im = tab[2].re*w[2].im - tab[3].im*w[3].im;
+
+    y[0].re = tab[0].im*t[5].re;
+    y[0].im = tab[0].im*t[5].im;
+#endif
+
+    x[4].re = x[1].re + x[2].re;
+    x[4].im = x[1].im + x[2].im;
+
+    y[4].re = y[1].re - y[2].re;
+    y[4].im = y[1].im - y[2].im;
+    x[1].re = z[0].re + x[1].re;
+    x[1].im = z[0].im + x[1].im;
+    y[1].re = y[0].re + y[1].re;
+    y[1].im = y[0].im + y[1].im;
+    x[2].re = z[0].re + x[2].re;
+    x[2].im = z[0].im + x[2].im;
+    y[2].re = y[2].re - y[0].re;
+    y[2].im = y[2].im - y[0].im;
+    x[4].re = z[0].re - x[4].re;
+    x[4].im = z[0].im - x[4].im;
+    y[4].re = y[0].re - y[4].re;
+    y[4].im = y[0].im - y[4].im;
+
+    out[1*stride] = (FFTComplex){ x[1].re + y[1].im, x[1].im - y[1].re };
+    out[2*stride] = (FFTComplex){ x[2].re + y[2].im, x[2].im - y[2].re };
+    out[3*stride] = (FFTComplex){ x[3].re + y[3].im, x[3].im - y[3].re };
+    out[4*stride] = (FFTComplex){ x[4].re + y[4].im, x[4].im - y[4].re };
+    out[5*stride] = (FFTComplex){ x[4].re - y[4].im, x[4].im + y[4].re };
+    out[6*stride] = (FFTComplex){ x[3].re - y[3].im, x[3].im + y[3].re };
+    out[7*stride] = (FFTComplex){ x[2].re - y[2].im, x[2].im + y[2].re };
+    out[8*stride] = (FFTComplex){ x[1].re - y[1].im, x[1].im + y[1].re };
+}
+
 static av_always_inline void fft15(FFTComplex *out, FFTComplex *in,
                                    ptrdiff_t stride)
 {
@@ -472,6 +606,7 @@  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(9)
 DECL_COMP_FFT(15)
 
 static void split_radix_fft(AVTXContext *s, void *_out, void *_in,
@@ -570,6 +705,7 @@  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(9)
 DECL_COMP_IMDCT(15)
 
 #define DECL_COMP_MDCT(N)                                                      \
@@ -619,6 +755,7 @@  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(9)
 DECL_COMP_MDCT(15)
 
 static void monolithic_imdct(AVTXContext *s, void *_dst, void *_src,
@@ -773,6 +910,7 @@  int TX_NAME(ff_tx_init_mdct_fft)(AVTXContext *s, av_tx_fn *tx,
         SRC /= FACTOR;                                                         \
     }
     CHECK_FACTOR(n, 15, len)
+    CHECK_FACTOR(n,  9, len)
     CHECK_FACTOR(n,  7, len)
     CHECK_FACTOR(n,  5, len)
     CHECK_FACTOR(n,  3, len)
@@ -817,11 +955,13 @@  int TX_NAME(ff_tx_init_mdct_fft)(AVTXContext *s, av_tx_fn *tx,
             *tx = n == 3 ? compound_fft_3xM :
                   n == 5 ? compound_fft_5xM :
                   n == 7 ? compound_fft_7xM :
+                  n == 9 ? compound_fft_9xM :
                            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 :
+                      n == 9 ? inv ? compound_imdct_9xM  : compound_mdct_9xM :
                                inv ? compound_imdct_15xM : compound_mdct_15xM;
         }
     } else { /* Direct transform case */
@@ -834,6 +974,8 @@  int TX_NAME(ff_tx_init_mdct_fft)(AVTXContext *s, av_tx_fn *tx,
         init_cos_tabs(0);
     else if (n == 7)
         init_cos_tabs(1);
+    else if (n == 9)
+        init_cos_tabs(2);
 
     if (m != 1 && !(m & (m - 1))) {
         if ((err = ff_tx_gen_ptwo_revtab(s, n == 1 && !is_mdct && !(flags & AV_TX_INPLACE))))