The Tor Browser: media/libopus/celt/celt_lpc.c@b8a032363ba2 (annotated)

media/libopus/celt/celt_lpc.c@b8a032363ba2 (annotated)

media/libopus/celt/celt_lpc.c

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* Copyright (c) 2009-2010 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.
    - 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 "celt_lpc.h"
 #include "stack_alloc.h"
 #include "mathops.h"
 #include "pitch.h"
 void _celt_lpc(
       opus_val16       *_lpc, /* out: [0...p-1] LPC coefficients      */
 const opus_val32 *ac,  /* in:  [0...p] autocorrelation values  */
 int          p
 )
 {
    int i, j;
    opus_val32 r;
    opus_val32 error = ac[0];
 #ifdef FIXED_POINT
    opus_val32 lpc[LPC_ORDER];
 #else
    float *lpc = _lpc;
 #endif
    for (i = 0; i < p; i++)
       lpc[i] = 0;
    if (ac[0] != 0)
    {
       for (i = 0; i < p; i++) {
          /* Sum up this iteration's reflection coefficient */
          opus_val32 rr = 0;
          for (j = 0; j < i; j++)
             rr += MULT32_32_Q31(lpc[j],ac[i - j]);
          rr += SHR32(ac[i + 1],3);
          r = -frac_div32(SHL32(rr,3), error);
          /*  Update LPC coefficients and total error */
          lpc[i] = SHR32(r,3);
          for (j = 0; j < (i+1)>>1; j++)
          {
             opus_val32 tmp1, tmp2;
             tmp1 = lpc[j];
             tmp2 = lpc[i-1-j];
             lpc[j]     = tmp1 + MULT32_32_Q31(r,tmp2);
             lpc[i-1-j] = tmp2 + MULT32_32_Q31(r,tmp1);
          }
          error = error - MULT32_32_Q31(MULT32_32_Q31(r,r),error);
          /* Bail out once we get 30 dB gain */
 #ifdef FIXED_POINT
          if (error<SHR32(ac[0],10))
             break;
 #else
          if (error<.001f*ac[0])
             break;
 #endif
       }
    }
 #ifdef FIXED_POINT
    for (i=0;i<p;i++)
       _lpc[i] = ROUND16(lpc[i],16);
 #endif
 }
 void celt_fir(const opus_val16 *_x,
          const opus_val16 *num,
          opus_val16 *_y,
          int N,
          int ord,
          opus_val16 *mem)
 {
    int i,j;
    VARDECL(opus_val16, rnum);
    VARDECL(opus_val16, x);
    SAVE_STACK;
    ALLOC(rnum, ord, opus_val16);
    ALLOC(x, N+ord, opus_val16);
    for(i=0;i<ord;i++)
       rnum[i] = num[ord-i-1];
    for(i=0;i<ord;i++)
       x[i] = mem[ord-i-1];
    for (i=0;i<N;i++)
       x[i+ord]=_x[i];
    for(i=0;i<ord;i++)
       mem[i] = _x[N-i-1];
 #ifdef SMALL_FOOTPRINT
    for (i=0;i<N;i++)
    {
       opus_val32 sum = SHL32(EXTEND32(_x[i]), SIG_SHIFT);
       for (j=0;j<ord;j++)
       {
          sum = MAC16_16(sum,rnum[j],x[i+j]);
       }
       _y[i] = SATURATE16(PSHR32(sum, SIG_SHIFT));
    }
 #else
    for (i=0;i<N-3;i+=4)
    {
       opus_val32 sum[4]={0,0,0,0};
       xcorr_kernel(rnum, x+i, sum, ord);
       _y[i  ] = SATURATE16(ADD32(EXTEND32(_x[i  ]), PSHR32(sum[0], SIG_SHIFT)));
       _y[i+1] = SATURATE16(ADD32(EXTEND32(_x[i+1]), PSHR32(sum[1], SIG_SHIFT)));
       _y[i+2] = SATURATE16(ADD32(EXTEND32(_x[i+2]), PSHR32(sum[2], SIG_SHIFT)));
       _y[i+3] = SATURATE16(ADD32(EXTEND32(_x[i+3]), PSHR32(sum[3], SIG_SHIFT)));
    }
    for (;i<N;i++)
    {
       opus_val32 sum = 0;
       for (j=0;j<ord;j++)
          sum = MAC16_16(sum,rnum[j],x[i+j]);
       _y[i] = SATURATE16(ADD32(EXTEND32(_x[i]), PSHR32(sum, SIG_SHIFT)));
    }
 #endif
    RESTORE_STACK;
 }
 void celt_iir(const opus_val32 *_x,
          const opus_val16 *den,
          opus_val32 *_y,
          int N,
          int ord,
          opus_val16 *mem)
 {
 #ifdef SMALL_FOOTPRINT
    int i,j;
    for (i=0;i<N;i++)
    {
       opus_val32 sum = _x[i];
       for (j=0;j<ord;j++)
       {
          sum -= MULT16_16(den[j],mem[j]);
       }
       for (j=ord-1;j>=1;j--)
       {
          mem[j]=mem[j-1];
       }
       mem[0] = ROUND16(sum,SIG_SHIFT);
       _y[i] = sum;
    }
 #else
    int i,j;
    VARDECL(opus_val16, rden);
    VARDECL(opus_val16, y);
    SAVE_STACK;
    celt_assert((ord&3)==0);
    ALLOC(rden, ord, opus_val16);
    ALLOC(y, N+ord, opus_val16);
    for(i=0;i<ord;i++)
       rden[i] = den[ord-i-1];
    for(i=0;i<ord;i++)
       y[i] = -mem[ord-i-1];
    for(;i<N+ord;i++)
       y[i]=0;
    for (i=0;i<N-3;i+=4)
    {
       /* Unroll by 4 as if it were an FIR filter */
       opus_val32 sum[4];
       sum[0]=_x[i];
       sum[1]=_x[i+1];
       sum[2]=_x[i+2];
       sum[3]=_x[i+3];
       xcorr_kernel(rden, y+i, sum, ord);
       /* Patch up the result to compensate for the fact that this is an IIR */
       y[i+ord  ] = -ROUND16(sum[0],SIG_SHIFT);
       _y[i  ] = sum[0];
       sum[1] = MAC16_16(sum[1], y[i+ord  ], den[0]);
       y[i+ord+1] = -ROUND16(sum[1],SIG_SHIFT);
       _y[i+1] = sum[1];
       sum[2] = MAC16_16(sum[2], y[i+ord+1], den[0]);
       sum[2] = MAC16_16(sum[2], y[i+ord  ], den[1]);
       y[i+ord+2] = -ROUND16(sum[2],SIG_SHIFT);
       _y[i+2] = sum[2];
       sum[3] = MAC16_16(sum[3], y[i+ord+2], den[0]);
       sum[3] = MAC16_16(sum[3], y[i+ord+1], den[1]);
       sum[3] = MAC16_16(sum[3], y[i+ord  ], den[2]);
       y[i+ord+3] = -ROUND16(sum[3],SIG_SHIFT);
       _y[i+3] = sum[3];
    }
    for (;i<N;i++)
    {
       opus_val32 sum = _x[i];
       for (j=0;j<ord;j++)
          sum -= MULT16_16(rden[j],y[i+j]);
       y[i+ord] = ROUND16(sum,SIG_SHIFT);
       _y[i] = sum;
    }
    for(i=0;i<ord;i++)
       mem[i] = _y[N-i-1];
    RESTORE_STACK;
 #endif
 }
 int _celt_autocorr(
                    const opus_val16 *x,   /*  in: [0...n-1] samples x   */
                    opus_val32       *ac,  /* out: [0...lag-1] ac values */
                    const opus_val16       *window,
                    int          overlap,
                    int          lag,
                    int          n,
                    int          arch
                   )
 {
    opus_val32 d;
    int i, k;
    int fastN=n-lag;
    int shift;
    const opus_val16 *xptr;
    VARDECL(opus_val16, xx);
    SAVE_STACK;
    ALLOC(xx, n, opus_val16);
    celt_assert(n>0);
    celt_assert(overlap>=0);
    if (overlap == 0)
    {
       xptr = x;
    } else {
       for (i=0;i<n;i++)
          xx[i] = x[i];
       for (i=0;i<overlap;i++)
       {
          xx[i] = MULT16_16_Q15(x[i],window[i]);
          xx[n-i-1] = MULT16_16_Q15(x[n-i-1],window[i]);
       }
       xptr = xx;
    }
    shift=0;
 #ifdef FIXED_POINT
    {
       opus_val32 ac0;
       ac0 = 1+(n<<7);
       if (n&1) ac0 += SHR32(MULT16_16(xptr[0],xptr[0]),9);
       for(i=(n&1);i<n;i+=2)
       {
          ac0 += SHR32(MULT16_16(xptr[i],xptr[i]),9);
          ac0 += SHR32(MULT16_16(xptr[i+1],xptr[i+1]),9);
       }
       shift = celt_ilog2(ac0)-30+10;
       shift = (shift)/2;
       if (shift>0)
       {
          for(i=0;i<n;i++)
             xx[i] = PSHR32(xptr[i], shift);
          xptr = xx;
       } else
          shift = 0;
    }
 #endif
    celt_pitch_xcorr(xptr, xptr, ac, fastN, lag+1, arch);
    for (k=0;k<=lag;k++)
    {
       for (i = k+fastN, d = 0; i < n; i++)
          d = MAC16_16(d, xptr[i], xptr[i-k]);
       ac[k] += d;
    }
 #ifdef FIXED_POINT
    shift = 2*shift;
    if (shift<=0)
       ac[0] += SHL32((opus_int32)1, -shift);
    if (ac[0] < 268435456)
    {
       int shift2 = 29 - EC_ILOG(ac[0]);
       for (i=0;i<=lag;i++)
          ac[i] = SHL32(ac[i], shift2);
       shift -= shift2;
    } else if (ac[0] >= 536870912)
    {
       int shift2=1;
       if (ac[0] >= 1073741824)
          shift2++;
       for (i=0;i<=lag;i++)
          ac[i] = SHR32(ac[i], shift2);
       shift += shift2;
    }
 #endif
    RESTORE_STACK;
    return shift;
 }

The Tor Browser / annotate

media/libopus/celt/celt_lpc.c@b8a032363ba2 (annotated)

media/libopus/celt/celt_lpc.c