Code for computing band energies and normalising: adapted from CEFT.

libcelt/Makefile.am

@@ -9,13 +9,14 @@
 lib_LTLIBRARIES = libcelt.la
 
 # Sources for compilation in the library
-libcelt_la_SOURCES = celt.c fftwrap.c mdct.c pitch.c smallft.c
+libcelt_la_SOURCES = bands.c celt.c fftwrap.c mdct.c pitch.c smallft.c
 
 #noinst_HEADERS =
 
 libcelt_la_LDFLAGS = -version-info @CELT_LT_CURRENT@:@CELT_LT_REVISION@:@CELT_LT_AGE@
 
-noinst_HEADERS = arch.h celt.h fftwrap.h mdct.h os_support.h pitch.h smallft.h
+noinst_HEADERS = arch.h bands.h celt.h fftwrap.h mdct.h os_support.h pitch.h \
+	smallft.h
 
 noinst_PROGRAMS = testcelt
 testcelt_SOURCES = testcelt.c

libcelt/bands.c

+/* (C) 2007 Jean-Marc Valin, CSIRO
+*/
+/*
+   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.
+   
+   - Neither the name of the Xiph.org Foundation nor the names of its
+   contributors may be used to endorse or promote products derived from
+   this software without specific prior written permission.
+   
+   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 FOUNDATION 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.
+*/
+
+#include <math.h>
+#include "bands.h"
+
+const int qbank[NBANDS+2] =   {0, 2, 4, 6, 8, 12, 16, 20, 24, 28, 36, 44, 52, 68, 84, 116, 128};
+
+
+/* Compute the energy in each of the bands */
+void compute_bands(float *X, int B, float *bank)
+{
+   int i;
+   for (i=0;i<NBANDS;i++)
+   {
+      int j;
+      bank[i] = 1e-10;
+      for (j=B*qbank[i];j<B*qbank[i+1];j++)
+         bank[i] += X[j]*X[j];
+      bank[i] = sqrt(bank[i]);
+   }
+}
+
+/* Normalise each band such that the energy is one. */
+void normalise_bands(float *X, int B, float *bank)
+{
+   int i;
+   for (i=0;i<NBANDS;i++)
+   {
+      int j;
+      float x = 1.f/bank[i];
+      for (j=B*qbank[i];j<B*qbank[i+1];j++)
+         X[j] *= x;
+   }
+   for (i=B*qbank[NBANDS];i<B*qbank[NBANDS+1];i++)
+      X[i] = 0;
+}
+
+/* De-normalise the energy to produce the synthesis from the unit-energy bands */
+void denormalise_bands(float *X, int B, float *bank)
+{
+   int i;
+   for (i=0;i<NBANDS;i++)
+   {
+      int j;
+      float x = bank[i];
+      for (j=B*qbank[i];j<B*qbank[i+1];j++)
+         X[j] *= x;
+   }
+   for (i=B*qbank[NBANDS];i<B*qbank[NBANDS+1];i++)
+      X[i] = 0;
+}
+
+
+/* Scales the pulse-codebook entry in each band such that unit-energy is conserved when 
+   adding the pitch */
+void pitch_renormalise_bands(float *X, int B, float *P)
+{
+   int i;
+   for (i=0;i<NBANDS;i++)
+   {
+      int j;
+      float Rpp=0;
+      float Rxp=0;
+      float Rxx=0;
+      float gain1;
+      for (j=B*qbank[i];j<B*qbank[i+1];j++)
+      {
+         Rxp += X[j]*P[j];
+         Rpp += P[j]*P[j];
+         Rxx += X[j]*X[j];
+      }
+      float arg = Rxp*Rxp + 1 - Rpp;
+      gain1 = sqrt(arg)-Rxp;
+      if (Rpp>.9999)
+         Rpp = .9999;
+      Rxx = 0;
+      for (j=B*qbank[i];j<B*qbank[i+1];j++)
+      {
+         X[j*2-1] = P[j]+gain1*X[j];
+         Rxx += X[j]*X[j];
+      }
+   }
+   for (i=B*qbank[NBANDS];i<B*qbank[NBANDS+1];i++)
+      X[i] = 0;
+}
+

libcelt/bands.h

+/* (C) 2007 Jean-Marc Valin, CSIRO
+*/
+/*
+   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.
+   
+   - Neither the name of the Xiph.org Foundation nor the names of its
+   contributors may be used to endorse or promote products derived from
+   this software without specific prior written permission.
+   
+   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 FOUNDATION 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.
+*/
+
+#ifndef BANDS_H
+#define BANDS_H
+
+#define NBANDS 15
+
+void compute_bands(float *X, int B, float *bands);
+
+void normalise_bands(float *X, int B, float *bands);
+
+void denormalise_bands(float *X, int B, float *bands);
+
+void pitch_renormalise_bands(float *X, int B, float *P);
+
+#endif /* BANDS_H */

libcelt/celt.c

@@ -35,6 +35,7 @@
 #include "celt.h"
 #include "pitch.h"
 #include "fftwrap.h"
+#include "bands.h"
 
 #define MAX_PERIOD 1024
 
@@ -53,6 +54,9 @@ struct CELTState_ {
    float *in_mem;
    float *mdct_overlap;
    float *out_mem;
+
+   float *bandE;
+
 };
 
 
@@ -74,7 +78,7 @@ CELTState *celt_encoder_new(int blockSize, int blocksPerFrame)
    st->in_mem = celt_alloc(N*sizeof(float));
    st->mdct_overlap = celt_alloc(N*sizeof(float));
    st->out_mem = celt_alloc(MAX_PERIOD*sizeof(float));
-
+   st->bandE = celt_alloc(NBANDS*sizeof(float));
    for (i=0;i<N;i++)
       st->window[i] = st->window[2*N-i-1] = sin(.5*M_PI* sin(.5*M_PI*(i+.5)/N) * sin(.5*M_PI*(i+.5)/N));
    return st;
@@ -94,6 +98,9 @@ void celt_encoder_destroy(CELTState *st)
    celt_free(st->in_mem);
    celt_free(st->mdct_overlap);
    celt_free(st->out_mem);
+   
+   celt_free(st->bandE);
+
    celt_free(st);
 }
 
@@ -121,8 +128,9 @@ int celt_encode(CELTState *st, short *pcm)
    N = st->block_size;
    B = st->nb_blocks;
    float in[(B+1)*N];
-   float X[B*N];
-   float P[B*N];
+   
+   float X[B*N]; /**< Interleaved signal MDCTs */
+   float P[B*N]; /**< Interleaved pitch MDCTs*/
    int pitch_index;
    
    /* FIXME: Add preemphasis */
@@ -156,12 +164,18 @@ int celt_encode(CELTState *st, short *pcm)
    printf ("\n");*/
    
    /* Band normalisation */
+   compute_bands(X, B, st->bandE);
+   normalise_bands(X, B, st->bandE);
+   
+   compute_bands(P, B, st->bandE);
+   normalise_bands(P, B, st->bandE);
 
    /* Pitch prediction */
 
    /* Residual quantisation */
    
    /* Synthesis */
+   denormalise_bands(X, B, st->bandE);
 
    CELT_MOVE(st->out_mem, st->out_mem+B*N, MAX_PERIOD-B*N);
    /* Compute inverse MDCTs */