Initial commit, some LPC stuff is already there...Initial

git-svn-id: http://svn.xiph.org/trunk/speex@3043 0101bb08-14d6-0310-b084-bc0e0c8e3800

5 files changed, 249 insertions, 0 deletions

diff --git a/libspeex/lpc.c b/libspeex/lpc.c
new file mode 100644
index 0000000..877a9cb
--- /dev/null
+++ b/libspeex/lpc.c
@@ -0,0 +1,90 @@
+/*
+  Copyright 1992, 1993, 1994 by Jutta Degener and Carsten Bormann,
+  Technische Universitaet Berlin
+
+  Any use of this software is permitted provided that this notice is not
+  removed and that neither the authors nor the Technische Universitaet Berlin
+  are deemed to have made any representations as to the suitability of this
+  software for any purpose nor are held responsible for any defects of
+  this software.  THERE IS ABSOLUTELY NO WARRANTY FOR THIS SOFTWARE.
+
+  As a matter of courtesy, the authors request to be informed about uses
+  this software has found, about bugs in this software, and about any
+  improvements that may be of general interest.
+
+  Berlin, 28.11.1994
+  Jutta Degener
+  Carsten Bormann
+*/
+
+
+/* LPC- and Reflection Coefficients
+ *
+ * The next two functions calculate linear prediction coefficients
+ * and/or the related reflection coefficients from the first P_MAX+1
+ * values of the autocorrelation function.
+ */
+
+/* Invented by N. Levinson in 1947, modified by J. Durbin in 1959.
+ */
+
+#include "lpc.h"
+
+float                      /* returns minimum mean square error    */
+wld(
+    float       * lpc, /*      [0...p-1] LPC coefficients      */
+    const float * ac,  /*  in: [0...p] autocorrelation values  */
+    float       * ref, /* out: [0...p-1] reflection coef's     */
+    int p
+    )
+{
+   int i, j;  float r, error = ac[0];
+
+   lpc[0]=1; //for compatibility
+   lpc++; //for compatibility
+
+   if (ac[0] == 0) {
+      for (i = 0; i < p; i++) ref[i] = 0; return 0; }
+
+   for (i = 0; i < p; i++) {
+
+      /* Sum up this iteration's reflection coefficient.
+       */
+      r = -ac[i + 1];
+      for (j = 0; j < i; j++) r -= lpc[j] * ac[i - j];
+      ref[i] = r /= error;
+
+      /*  Update LPC coefficients and total error.
+       */
+      lpc[i] = r;
+      for (j = 0; j < i/2; j++) {
+         float tmp  = lpc[j];
+         lpc[j]     += r * lpc[i-1-j];
+         lpc[i-1-j] += r * tmp;
+      }
+      if (i % 2) lpc[j] += lpc[j] * r;
+
+      error *= 1.0 - r * r;
+   }
+   return error;
+}
+
+
+/* Compute the autocorrelation
+ *                      ,--,
+ *              ac(i) = >  x(n) * x(n-i)  for all n
+ *                      `--'
+ * for lags between 0 and lag-1, and x == 0 outside 0...n-1
+ */
+void autocorr(
+              const float * x,   /*  in: [0...n-1] samples x   */
+              float *ac,   /* out: [0...lag-1] ac values */
+              int lag, int   n)
+{
+   float d; int i;
+   lag++;   //Compensate for the old routine
+   while (lag--) {
+      for (i = lag, d = 0; i < n; i++) d += x[i] * x[i-lag];
+      ac[lag] = d;
+   }
+}
diff --git a/libspeex/lpc.h b/libspeex/lpc.h
new file mode 100644
index 0000000..b87120e
--- /dev/null
+++ b/libspeex/lpc.h
@@ -0,0 +1,18 @@
+#ifndef LPC_H
+#define LPC_H
+
+void autocorr(
+        const float * x,   /*  in: [0...n-1] samples x   */
+        float *ac,   /* out: [0...lag-1] ac values */
+        int lag, int   n);
+
+float                      /* returns minimum mean square error    */
+wld(
+        float       * lpc, /*      [0...p-1] LPC coefficients      */
+        const float * ac,  /*  in: [0...p] autocorrelation values  */
+        float       * ref, /* out: [0...p-1] reflection coef's     */
+        int p
+        );
+
+
+#endif
diff --git a/libspeex/speex.c b/libspeex/speex.c
new file mode 100644
index 0000000..528e192
--- /dev/null
+++ b/libspeex/speex.c
@@ -0,0 +1,75 @@
+#include "speex.h"
+#include "lpc.h"
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+
+void encoder_init(EncState *st)
+{
+   int i;
+   st->frameSize = 128;
+   st->windowSize = 256;
+   st->subframeSize=64;
+   st->lpcSize = 10;
+   st->bufSize = 256;
+   st->inBuf = malloc(st->bufSize*sizeof(float));
+   for (i=0;i<st->bufSize;i++)
+      st->inBuf[i]=0;
+   st->window = malloc(st->windowSize*sizeof(float));
+   /* Hanning window */
+   for (i=0;i<st->windowSize;i++)
+      st->window[i]=.5*(1-cos(2*M_PI*i/st->windowSize));
+   st->buf2 = malloc(st->windowSize*sizeof(float));
+   st->lpc = malloc(st->lpcSize*sizeof(float));
+   st->autocorr = malloc(st->lpcSize*sizeof(float));
+   st->lsf = malloc(st->lpcSize*sizeof(float));
+   st->rc = malloc(st->lpcSize*sizeof(float));
+}
+
+void encoder_destroy(EncState *st)
+{
+   free(st->inBuf);
+   free(st->window);
+   free(st->buf2);
+   free(st->lpc);
+   free(st->autocorr);
+   free(st->lsf);
+   free(st->rc);
+}
+
+void encode(EncState *st, float *in, int *outSize, void *bits)
+{
+   int i;
+   float error;
+
+   /* Copy new data in input buffer */
+   memmove(st->inBuf, st->inBuf+st->bufSize-st->frameSize, (st->bufSize-st->frameSize)*sizeof(float));
+   for (i=0;i<st->frameSize;i++)
+      st->inBuf[st->bufSize-st->frameSize+i] = in[i];
+
+   /* Window for analysis */
+   for (i=0;i<st->windowSize;i++)
+      st->buf2[i] = st->inBuf[i] * st->window[i];
+   
+   autocorr(st->buf2, st->autocorr, st->lpcSize-1, st->windowSize);
+   st->autocorr[0] += 1;        /* prevents nan */
+   st->autocorr[0] *= 1.0001;   /* 40 dB noise floor */
+   /*Should do lag windowing here */
+   error = wld(st->lpc, st->autocorr, st->rc, st->lpcSize-1);
+   printf ("prediction error = %f, R[0] = %f, gain = %f\n", error, st->autocorr[0], 
+           st->autocorr[0]/error);
+
+}
+
+
+void decoder_init(DecState *st)
+{
+}
+
+void decoder_destroy(DecState *st)
+{
+}
+
+void decode(DecState *st, float *bits, float *out)
+{
+}
diff --git a/libspeex/speex.h b/libspeex/speex.h
new file mode 100644
index 0000000..74bdd40
--- /dev/null
+++ b/libspeex/speex.h
@@ -0,0 +1,33 @@
+#ifndef SPEEX_H
+#define SPEEX_H
+
+
+typedef struct EncState {
+   int    frameSize;
+   int    subframeSize;
+   int    lpcSize;
+   int    bufSize;
+   float *inBuf;
+   float *window;
+   int    windowSize;
+   float *buf2;
+   float *autocorr;
+   float *lpc;
+   float *lsf;
+   float *rc;
+} EncState;
+
+typedef struct DecState {
+} DecState;
+
+void encoder_init(EncState *st);
+void encoder_destroy(EncState *st);
+void encode(EncState *st, float *in, int *outSize, void *bits);
+
+void decoder_init(DecState *st);
+void decoder_destroy(DecState *st);
+void decode(DecState *st, float *bits, float *out);
+
+
+
+#endif
diff --git a/libspeex/testenc.c b/libspeex/testenc.c
new file mode 100644
index 0000000..53e34d3
--- /dev/null
+++ b/libspeex/testenc.c
@@ -0,0 +1,33 @@
+#include "speex.h"
+#include <stdio.h>
+#include <stdlib.h>
+
+#define FRAME_SIZE 128
+
+main(int argc, char **argv)
+{
+   char *inFile, *outFile;
+   FILE *fin, *fout;
+   short in[FRAME_SIZE];
+   float input[FRAME_SIZE];
+   int i;
+   EncState st;
+
+   encoder_init(&st);
+   if (argc != 3)
+   {
+      fprintf (stderr, "Usage: encode [in file] [out file]\n");
+      exit(1);
+   }
+   inFile = argv[1];
+   fin = fopen(inFile, "r");
+   outFile = argv[2];
+   fout = fopen(outFile, "w");
+   while (!feof(fin))
+   {
+      fread(in, sizeof(short), FRAME_SIZE, fin);
+      for (i=0;i<FRAME_SIZE;i++)
+         input[i]=in[i];
+      encode(&st, input, NULL, NULL);
+   }
+}