chromium/third_party/opus/src/celt/pitch.c

/* Copyright (c) 2007-2008 CSIRO
   Copyright (c) 2007-2009 Xiph.Org Foundation
   Written by Jean-Marc Valin */
/**
   @file pitch.c
   @brief Pitch analysis
 */

/*
   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.

   - Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   documentation and/or other materials provided with the distribution.

   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
   OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
   EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "pitch.h"
#include "os_support.h"
#include "modes.h"
#include "stack_alloc.h"
#include "mathops.h"
#include "celt_lpc.h"

static void find_best_pitch(opus_val32 *xcorr, opus_val16 *y, int len,
                            int max_pitch, int *best_pitch
#ifdef FIXED_POINT
                            , int yshift, opus_val32 maxcorr
#endif
                            )
{ … }

static void celt_fir5(opus_val16 *x,
         const opus_val16 *num,
         int N)
{ … }


void pitch_downsample(celt_sig * OPUS_RESTRICT x[], opus_val16 * OPUS_RESTRICT x_lp,
      int len, int C, int arch)
{ … }

/* Pure C implementation. */
#ifdef FIXED_POINT
opus_val32
#else
void
#endif
celt_pitch_xcorr_c(const opus_val16 *_x, const opus_val16 *_y,
      opus_val32 *xcorr, int len, int max_pitch, int arch)
{ … }

void pitch_search(const opus_val16 * OPUS_RESTRICT x_lp, opus_val16 * OPUS_RESTRICT y,
                  int len, int max_pitch, int *pitch, int arch)
{ … }

#ifdef FIXED_POINT
static opus_val16 compute_pitch_gain(opus_val32 xy, opus_val32 xx, opus_val32 yy)
{
   opus_val32 x2y2;
   int sx, sy, shift;
   opus_val32 g;
   opus_val16 den;
   if (xy == 0 || xx == 0 || yy == 0)
      return 0;
   sx = celt_ilog2(xx)-14;
   sy = celt_ilog2(yy)-14;
   shift = sx + sy;
   x2y2 = SHR32(MULT16_16(VSHR32(xx, sx), VSHR32(yy, sy)), 14);
   if (shift & 1) {
      if (x2y2 < 32768)
      {
         x2y2 <<= 1;
         shift--;
      } else {
         x2y2 >>= 1;
         shift++;
      }
   }
   den = celt_rsqrt_norm(x2y2);
   g = MULT16_32_Q15(den, xy);
   g = VSHR32(g, (shift>>1)-1);
   return EXTRACT16(MIN32(g, Q15ONE));
}
#else
static opus_val16 compute_pitch_gain(opus_val32 xy, opus_val32 xx, opus_val32 yy)
{ … }
#endif

static const int second_check[16] = …;
opus_val16 remove_doubling(opus_val16 *x, int maxperiod, int minperiod,
      int N, int *T0_, int prev_period, opus_val16 prev_gain, int arch)
{ … }