Update to opus-HEAD-66611f1.

celt/mdct.c

 /* Copyright (c) 2007-2008 CSIRO
    Copyright (c) 2007-2008 Xiph.Org Foundation
    Written by Jean-Marc Valin */
 /*
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:
 
    - Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
@@ skipping 35 matching lines @@
 #endif
 
 #include "mdct.h"
 #include "kiss_fft.h"
 #include "_kiss_fft_guts.h"
 #include <math.h>
 #include "os_support.h"
 #include "mathops.h"
 #include "stack_alloc.h"
 
+#if defined(MIPSr1_ASM)
+#include "mips/mdct_mipsr1.h"
+#endif
+
+
 #ifdef CUSTOM_MODES
 
 int clt_mdct_init(mdct_lookup *l,int N, int maxshift)
 {
    int i;
-   int N4;
    kiss_twiddle_scalar *trig;
-#if defined(FIXED_POINT)
+   int shift;
    int N2=N>>1;
-#endif
    l->n = N;
-   N4 = N>>2;
    l->maxshift = maxshift;
    for (i=0;i<=maxshift;i++)
    {
       if (i==0)
          l->kfft[i] = opus_fft_alloc(N>>2>>i, 0, 0);
       else
          l->kfft[i] = opus_fft_alloc_twiddles(N>>2>>i, 0, 0, l->kfft[0]);
 #ifndef ENABLE_TI_DSPLIB55
       if (l->kfft[i]==NULL)
          return 0;
 #endif
    }
-   l->trig = trig = (kiss_twiddle_scalar*)opus_alloc((N4+1)*sizeof(kiss_twiddle_scalar));
+   l->trig = trig = (kiss_twiddle_scalar*)opus_alloc((N-(N2>>maxshift))*sizeof(kiss_twiddle_scalar));
    if (l->trig==NULL)
      return 0;
-   /* We have enough points that sine isn't necessary */
+   for (shift=0;shift<=maxshift;shift++)
+   {
+      /* We have enough points that sine isn't necessary */
 #if defined(FIXED_POINT)
-   for (i=0;i<=N4;i++)
-      trig[i] = TRIG_UPSCALE*celt_cos_norm(DIV32(ADD32(SHL32(EXTEND32(i),17),N2),N));
+#if 1
+      for (i=0;i<N2;i++)
+         trig[i] = TRIG_UPSCALE*celt_cos_norm(DIV32(ADD32(SHL32(EXTEND32(i),17),N2+16384),N));
 #else
-   for (i=0;i<=N4;i++)
-      trig[i] = (kiss_twiddle_scalar)cos(2*PI*i/N);
+      for (i=0;i<N2;i++)
+         trig[i] = (kiss_twiddle_scalar)MAX32(-32767,MIN32(32767,floor(.5+32768*cos(2*M_PI*(i+.125)/N))));
 #endif
+#else
+      for (i=0;i<N2;i++)
+         trig[i] = (kiss_twiddle_scalar)cos(2*PI*(i+.125)/N);
+#endif
+      trig += N2;
+      N2 >>= 1;
+      N >>= 1;
+   }
    return 1;
 }
 
 void clt_mdct_clear(mdct_lookup *l)
 {
    int i;
    for (i=0;i<=l->maxshift;i++)
       opus_fft_free(l->kfft[i]);
    opus_free((kiss_twiddle_scalar*)l->trig);
 }
 
 #endif /* CUSTOM_MODES */
 
 /* Forward MDCT trashes the input array */
+#ifndef OVERRIDE_clt_mdct_forward
 void clt_mdct_forward(const mdct_lookup *l, kiss_fft_scalar *in, kiss_fft_scalar * OPUS_RESTRICT out,
       const opus_val16 *window, int overlap, int shift, int stride)
 {
    int i;
    int N, N2, N4;
-   kiss_twiddle_scalar sine;
    VARDECL(kiss_fft_scalar, f);
-   VARDECL(kiss_fft_scalar, f2);
+   VARDECL(kiss_fft_cpx, f2);
+   const kiss_fft_state *st = l->kfft[shift];
+   const kiss_twiddle_scalar *trig;
+   opus_val16 scale;
+#ifdef FIXED_POINT
+   /* Allows us to scale with MULT16_32_Q16(), which is faster than
+      MULT16_32_Q15() on ARM. */
+   int scale_shift = st->scale_shift-1;
+#endif
    SAVE_STACK;
+   scale = st->scale;
+
    N = l->n;
-   N >>= shift;
+   trig = l->trig;
+   for (i=0;i<shift;i++)
+   {
+      N >>= 1;
+      trig += N;
+   }
    N2 = N>>1;
    N4 = N>>2;
+
    ALLOC(f, N2, kiss_fft_scalar);
-   ALLOC(f2, N2, kiss_fft_scalar);
-   /* sin(x) ~= x here */
-#ifdef FIXED_POINT
-   sine = TRIG_UPSCALE*(QCONST16(0.7853981f, 15)+N2)/N;
-#else
-   sine = (kiss_twiddle_scalar)2*PI*(.125f)/N;
-#endif
+   ALLOC(f2, N4, kiss_fft_cpx);
 
    /* Consider the input to be composed of four blocks: [a, b, c, d] */
    /* Window, shuffle, fold */
    {
       /* Temp pointers to make it really clear to the compiler what we're doing */
       const kiss_fft_scalar * OPUS_RESTRICT xp1 = in+(overlap>>1);
       const kiss_fft_scalar * OPUS_RESTRICT xp2 = in+N2-1+(overlap>>1);
       kiss_fft_scalar * OPUS_RESTRICT yp = f;
       const opus_val16 * OPUS_RESTRICT wp1 = window+(overlap>>1);
       const opus_val16 * OPUS_RESTRICT wp2 = window+(overlap>>1)-1;
@@ skipping 24 matching lines @@
          *yp++ = MULT16_32_Q15(*wp2, *xp1)     + MULT16_32_Q15(*wp1, xp2[N2]);
          xp1+=2;
          xp2-=2;
          wp1+=2;
          wp2-=2;
       }
    }
    /* Pre-rotation */
    {
       kiss_fft_scalar * OPUS_RESTRICT yp = f;
-      const kiss_twiddle_scalar *t = &l->trig[0];
+      const kiss_twiddle_scalar *t = &trig[0];
       for(i=0;i<N4;i++)
       {
+         kiss_fft_cpx yc;
+         kiss_twiddle_scalar t0, t1;
          kiss_fft_scalar re, im, yr, yi;
-         re = yp[0];
-         im = yp[1];
-         yr = -S_MUL(re,t[i<<shift])  -  S_MUL(im,t[(N4-i)<<shift]);
-         yi = -S_MUL(im,t[i<<shift])  +  S_MUL(re,t[(N4-i)<<shift]);
-         /* works because the cos is nearly one */
-         *yp++ = yr + S_MUL(yi,sine);
-         *yp++ = yi - S_MUL(yr,sine);
+         t0 = t[i];
+         t1 = t[N4+i];
+         re = *yp++;
+         im = *yp++;
+         yr = S_MUL(re,t0)  -  S_MUL(im,t1);
+         yi = S_MUL(im,t0)  +  S_MUL(re,t1);
+         yc.r = yr;
+         yc.i = yi;
+         yc.r = PSHR32(MULT16_32_Q16(scale, yc.r), scale_shift);
+         yc.i = PSHR32(MULT16_32_Q16(scale, yc.i), scale_shift);
+         f2[st->bitrev[i]] = yc;
       }
    }
 
-   /* N/4 complex FFT, down-scales by 4/N */
-   opus_fft(l->kfft[shift], (kiss_fft_cpx *)f, (kiss_fft_cpx *)f2);
+   /* N/4 complex FFT, does not downscale anymore */
+   opus_fft_impl(st, f2);
 
    /* Post-rotate */
    {
       /* Temp pointers to make it really clear to the compiler what we're doing */
-      const kiss_fft_scalar * OPUS_RESTRICT fp = f2;
+      const kiss_fft_cpx * OPUS_RESTRICT fp = f2;
       kiss_fft_scalar * OPUS_RESTRICT yp1 = out;
       kiss_fft_scalar * OPUS_RESTRICT yp2 = out+stride*(N2-1);
-      const kiss_twiddle_scalar *t = &l->trig[0];
+      const kiss_twiddle_scalar *t = &trig[0];
       /* Temp pointers to make it really clear to the compiler what we're doing */
       for(i=0;i<N4;i++)
       {
          kiss_fft_scalar yr, yi;
-         yr = S_MUL(fp[1],t[(N4-i)<<shift]) + S_MUL(fp[0],t[i<<shift]);
-         yi = S_MUL(fp[0],t[(N4-i)<<shift]) - S_MUL(fp[1],t[i<<shift]);
-         /* works because the cos is nearly one */
-         *yp1 = yr - S_MUL(yi,sine);
-         *yp2 = yi + S_MUL(yr,sine);;
-         fp += 2;
+         yr = S_MUL(fp->i,t[N4+i]) - S_MUL(fp->r,t[i]);
+         yi = S_MUL(fp->r,t[N4+i]) + S_MUL(fp->i,t[i]);
+         *yp1 = yr;
+         *yp2 = yi;
+         fp++;
          yp1 += 2*stride;
          yp2 -= 2*stride;
       }
    }
    RESTORE_STACK;
 }
+#endif /* OVERRIDE_clt_mdct_forward */
 
+#ifndef OVERRIDE_clt_mdct_backward
 void clt_mdct_backward(const mdct_lookup *l, kiss_fft_scalar *in, kiss_fft_scalar * OPUS_RESTRICT out,
       const opus_val16 * OPUS_RESTRICT window, int overlap, int shift, int stride)
 {
    int i;
    int N, N2, N4;
-   kiss_twiddle_scalar sine;
-   VARDECL(kiss_fft_scalar, f2);
-   SAVE_STACK;
+   const kiss_twiddle_scalar *trig;
+
    N = l->n;
-   N >>= shift;
+   trig = l->trig;
+   for (i=0;i<shift;i++)
+   {
+      N >>= 1;
+      trig += N;
+   }
    N2 = N>>1;
    N4 = N>>2;
-   ALLOC(f2, N2, kiss_fft_scalar);
-   /* sin(x) ~= x here */
-#ifdef FIXED_POINT
-   sine = TRIG_UPSCALE*(QCONST16(0.7853981f, 15)+N2)/N;
-#else
-   sine = (kiss_twiddle_scalar)2*PI*(.125f)/N;
-#endif
 
    /* Pre-rotate */
    {
       /* Temp pointers to make it really clear to the compiler what we're doing */
       const kiss_fft_scalar * OPUS_RESTRICT xp1 = in;
       const kiss_fft_scalar * OPUS_RESTRICT xp2 = in+stride*(N2-1);
-      kiss_fft_scalar * OPUS_RESTRICT yp = f2;
-      const kiss_twiddle_scalar *t = &l->trig[0];
+      kiss_fft_scalar * OPUS_RESTRICT yp = out+(overlap>>1);
+      const kiss_twiddle_scalar * OPUS_RESTRICT t = &trig[0];
+      const opus_int16 * OPUS_RESTRICT bitrev = l->kfft[shift]->bitrev;
       for(i=0;i<N4;i++)
       {
+         int rev;
          kiss_fft_scalar yr, yi;
-         yr = -S_MUL(*xp2, t[i<<shift]) + S_MUL(*xp1,t[(N4-i)<<shift]);
-         yi =  -S_MUL(*xp2, t[(N4-i)<<shift]) - S_MUL(*xp1,t[i<<shift]);
-         /* works because the cos is nearly one */
-         *yp++ = yr - S_MUL(yi,sine);
-         *yp++ = yi + S_MUL(yr,sine);
+         rev = *bitrev++;
+         yr = S_MUL(*xp2, t[i]) + S_MUL(*xp1, t[N4+i]);
+         yi = S_MUL(*xp1, t[i]) - S_MUL(*xp2, t[N4+i]);
+         /* We swap real and imag because we use an FFT instead of an IFFT. */
+         yp[2*rev+1] = yr;
+         yp[2*rev] = yi;
+         /* Storing the pre-rotation directly in the bitrev order. */
          xp1+=2*stride;
          xp2-=2*stride;
       }
    }
 
-   /* Inverse N/4 complex FFT. This one should *not* downscale even in fixed-point */
-   opus_ifft(l->kfft[shift], (kiss_fft_cpx *)f2, (kiss_fft_cpx *)(out+(overlap>>1)));
+   opus_fft_impl(l->kfft[shift], (kiss_fft_cpx*)(out+(overlap>>1)));
 
    /* Post-rotate and de-shuffle from both ends of the buffer at once to make
       it in-place. */
    {
-      kiss_fft_scalar * OPUS_RESTRICT yp0 = out+(overlap>>1);
-      kiss_fft_scalar * OPUS_RESTRICT yp1 = out+(overlap>>1)+N2-2;
-      const kiss_twiddle_scalar *t = &l->trig[0];
+      kiss_fft_scalar * yp0 = out+(overlap>>1);
+      kiss_fft_scalar * yp1 = out+(overlap>>1)+N2-2;
+      const kiss_twiddle_scalar *t = &trig[0];
       /* Loop to (N4+1)>>1 to handle odd N4. When N4 is odd, the
          middle pair will be computed twice. */
       for(i=0;i<(N4+1)>>1;i++)
       {
          kiss_fft_scalar re, im, yr, yi;
          kiss_twiddle_scalar t0, t1;
-         re = yp0[0];
-         im = yp0[1];
-         t0 = t[i<<shift];
-         t1 = t[(N4-i)<<shift];
+         /* We swap real and imag because we're using an FFT instead of an IFFT. */
+         re = yp0[1];
+         im = yp0[0];
+         t0 = t[i];
+         t1 = t[N4+i];
          /* We'd scale up by 2 here, but instead it's done when mixing the windows */
-         yr = S_MUL(re,t0) - S_MUL(im,t1);
-         yi = S_MUL(im,t0) + S_MUL(re,t1);
-         re = yp1[0];
-         im = yp1[1];
-         /* works because the cos is nearly one */
-         yp0[0] = -(yr - S_MUL(yi,sine));
-         yp1[1] = yi + S_MUL(yr,sine);
+         yr = S_MUL(re,t0) + S_MUL(im,t1);
+         yi = S_MUL(re,t1) - S_MUL(im,t0);
+         /* We swap real and imag because we're using an FFT instead of an IFFT. */
+         re = yp1[1];
+         im = yp1[0];
+         yp0[0] = yr;
+         yp1[1] = yi;
 
-         t0 = t[(N4-i-1)<<shift];
-         t1 = t[(i+1)<<shift];
+         t0 = t[(N4-i-1)];
+         t1 = t[(N2-i-1)];
          /* We'd scale up by 2 here, but instead it's done when mixing the windows */
-         yr = S_MUL(re,t0) - S_MUL(im,t1);
-         yi = S_MUL(im,t0) + S_MUL(re,t1);
-         /* works because the cos is nearly one */
-         yp1[0] = -(yr - S_MUL(yi,sine));
-         yp0[1] = yi + S_MUL(yr,sine);
+         yr = S_MUL(re,t0) + S_MUL(im,t1);
+         yi = S_MUL(re,t1) - S_MUL(im,t0);
+         yp1[0] = yr;
+         yp0[1] = yi;
          yp0 += 2;
          yp1 -= 2;
       }
    }
 
    /* Mirror on both sides for TDAC */
    {
       kiss_fft_scalar * OPUS_RESTRICT xp1 = out+overlap-1;
       kiss_fft_scalar * OPUS_RESTRICT yp1 = out;
       const opus_val16 * OPUS_RESTRICT wp1 = window;
       const opus_val16 * OPUS_RESTRICT wp2 = window+overlap-1;
 
       for(i = 0; i < overlap/2; i++)
       {
          kiss_fft_scalar x1, x2;
          x1 = *xp1;
          x2 = *yp1;
          *yp1++ = MULT16_32_Q15(*wp2, x2) - MULT16_32_Q15(*wp1, x1);
          *xp1-- = MULT16_32_Q15(*wp1, x2) + MULT16_32_Q15(*wp2, x1);
          wp1++;
          wp2--;
       }
    }
-   RESTORE_STACK;
 }
+#endif /* OVERRIDE_clt_mdct_backward */