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-rw-r--r--libspeex/quant_lsp.h5
-rw-r--r--libspeex/speex.c54
2 files changed, 33 insertions, 26 deletions
diff --git a/libspeex/quant_lsp.h b/libspeex/quant_lsp.h
index cc6e146..d0a1e94 100644
--- a/libspeex/quant_lsp.h
+++ b/libspeex/quant_lsp.h
@@ -14,14 +14,17 @@
#define NB_CDBK_SIZE_HIGH1 64
#define NB_CDBK_SIZE_HIGH2 64
+/*Narrowband codebooks*/
extern float cdbk_nb[];
extern float cdbk_nb_low1[];
extern float cdbk_nb_low2[];
extern float cdbk_nb_high1[];
extern float cdbk_nb_high2[];
-
+/* Quantizes narrowband LSPs with 30 bits */
unsigned int lsp_quant_nb(float *lsp, int order);
+
+/* Decodes quantized narrowband LSPs */
void lsp_unquant_nb(float *lsp, int order, unsigned int id);
#endif
diff --git a/libspeex/speex.c b/libspeex/speex.c
index 7b7019e..de72333 100644
--- a/libspeex/speex.c
+++ b/libspeex/speex.c
@@ -21,6 +21,7 @@
void encoder_init(EncState *st)
{
int i;
+ /* Codec parameters, should eventually have several "modes"*/
st->frameSize = 160;
st->windowSize = 320;
st->nbSubframes=4;
@@ -28,6 +29,7 @@ void encoder_init(EncState *st)
st->lpcSize = 10;
st->bufSize = 640;
st->gamma=.9;
+
st->inBuf = malloc(st->bufSize*sizeof(float));
st->frame = st->inBuf + st->bufSize - st->windowSize;
st->wBuf = malloc(st->bufSize*sizeof(float));
@@ -36,15 +38,18 @@ void encoder_init(EncState *st)
st->inBuf[i]=0;
for (i=0;i<st->bufSize;i++)
st->wBuf[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+1)*sizeof(float));
st->interp_lpc = malloc((st->lpcSize+1)*sizeof(float));
st->bw_lpc = malloc((st->lpcSize+1)*sizeof(float));
st->autocorr = malloc((st->lpcSize+1)*sizeof(float));
+
/* Create the window for autocorrelation (lag-windowing) */
st->lagWindow = malloc((st->lpcSize+1)*sizeof(float));
for (i=0;i<st->lpcSize+1;i++)
@@ -58,6 +63,7 @@ void encoder_init(EncState *st)
void encoder_destroy(EncState *st)
{
+ /* Free all allocated memory */
free(st->inBuf);
free(st->wBuf);
free(st->window);
@@ -87,24 +93,24 @@ void encode(EncState *st, float *in, int *outSize, void *bits)
/* Window for analysis */
for (i=0;i<st->windowSize;i++)
st->buf2[i] = st->frame[i] * st->window[i];
+
/* Compute auto-correlation */
autocorr(st->buf2, st->autocorr, st->lpcSize+1, st->windowSize);
+
st->autocorr[0] += 1; /* prevents NANs */
st->autocorr[0] *= 1.0001; /* 40 dB noise floor */
- /* Perform lag windowing here, equivalent to filtering in the power-spectrum domain */
+ /* Lag windowing: equivalent to filtering in the power-spectrum domain */
for (i=0;i<st->lpcSize+1;i++)
st->autocorr[i] *= st->lagWindow[i];
+
/* Levinson-Durbin */
- /*for (i=0;i<st->lpcSize+1;i++)
- printf("%f ", st->autocorr[i]);
- printf ("\n");
- */
error = wld(st->lpc+1, st->autocorr, st->rc, st->lpcSize);
st->lpc[0]=1;
+ /*printf ("prediction error = %f, R[0] = %f, gain = %f\n", error, st->autocorr[0], st->autocorr[0]/error);*/
+
/*for (i=0;i<st->lpcSize+1;i++)
- printf("%f ", st->lpc[i]);
- printf ("\n");*/
- printf ("prediction error = %f, R[0] = %f, gain = %f\n", error, st->autocorr[0], st->autocorr[0]/error);
+ printf("%f ", st->lpc[i]);
+ printf ("aa\n");*/
/* LPC to LSPs (x-domain) transform */
roots=lpc_to_lsp (st->lpc, st->lpcSize, st->lsp, 6, 0.02);
@@ -113,6 +119,8 @@ void encode(EncState *st, float *in, int *outSize, void *bits)
fprintf (stderr, "roots!=st->lpcSize\n");
exit(1);
}
+
+ /* x-domain to angle domain*/
for (i=0;i<st->lpcSize;i++)
st->lsp[i] = acos(st->lsp[i]);
@@ -127,17 +135,15 @@ void encode(EncState *st, float *in, int *outSize, void *bits)
lsp_unquant_nb(st->lsp,10,id);
}
- /*for (i=0;i<roots;i++)
- printf("%f ", st->lsp[i]);
- printf ("\n");*/
-
-#if 1
+ /* Loop on all sub-frames */
for (sub=0;sub<st->nbSubframes;sub++)
{
float tmp, tmp1,tmp2,gain[3];
int pitch, offset;
+ /* Offset relative to start of frame */
offset = st->subframeSize*sub;
+
/* LSP interpolation */
tmp = (.5 + sub)/st->nbSubframes;
for (i=0;i<st->lpcSize;i++)
@@ -164,7 +170,7 @@ void encode(EncState *st, float *in, int *outSize, void *bits)
printf("%f ", st->bw_lpc[i]);
printf ("\n");*/
- /* Compute perceptualy weighted residue */
+ /* Compute perceptualy weighted residue (FIR) */
for (i=0;i<st->subframeSize;i++)
{
st->wframe[offset+i]=st->frame[offset+i];
@@ -172,31 +178,26 @@ void encode(EncState *st, float *in, int *outSize, void *bits)
st->wframe[offset+i] += st->frame[offset+i-j]*st->bw_lpc[j];
}
- /* Find pitch gain and delay */
+ /* Find pitch gain and delay, gains are already quantized*/
pitch = ltp_closed_loop(st->wframe+offset, st->subframeSize, 20, 120, gain);
/*pitch = three_tap_ltp(st->wframe+offset, st->subframeSize, 20, 120, gain);*/
- /*pitch = open_loop_ltp(st->wframe+offset, st->subframeSize, 20, 120, gain);*/
-
- /* Quantization of pitch period and gains */
- /*printf ("pitch = %d, gain = %f\n",pitch,gain);*/
- printf ("pitch = %d, gain = %f %f %f\n",pitch,gain[0], gain[1], gain[2]);
+ printf ("pitch = %d, gains = %f %f %f\n",pitch,gain[0], gain[1], gain[2]);
/*printf ("%f %f %f ",gain[0], gain[1], gain[2]);*/
tmp1=0;
for (i=0;i<st->subframeSize;i++)
tmp1+=st->wframe[offset+i]*st->wframe[offset+i];
- /*printf ("before: %f ", tmp1);*/
predictor_three_tap(st->wframe+offset, st->subframeSize, pitch, gain);
tmp2=0;
for (i=0;i<st->subframeSize;i++)
tmp2+=st->wframe[offset+i]*st->wframe[offset+i];
- /*printf ("after: %f\n", tmp2);*/
- printf ("pitch gain: %f\n", tmp1/(tmp2+.001));
+ printf ("pitch prediction gain: %f\n", tmp1/(tmp2+.001));
- /*Analysis by synthesis and quantization here*/
+ /*Analysis by synthesis and excitation quantization here*/
+ /* Reverse the 3-tab pitch predictor (IIR)*/
inverse_three_tap(st->wframe+offset, st->subframeSize, pitch, gain);
/*Inverse short-term predictor (1/W(z/gamma))*/
@@ -208,11 +209,14 @@ void encode(EncState *st, float *in, int *outSize, void *bits)
}
}
-#endif
+
printf ("\n");
+ /* Store the LSPs for interpolation in the next frame */
for (i=0;i<st->lpcSize;i++)
st->old_lsp[i] = st->lsp[i];
+ /* The next frame will not by the first (Duh!) */
st->first = 0;
+ /* Replace input by synthesized speech */
for (i=0;i<st->frameSize;i++)
in[i]=st->frame[i];
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-02 03:49:24 +0300