From 52a2198ad7ebc5f0b44eeff27f05d36a45d21629 Mon Sep 17 00:00:00 2001
From: David <david@rowetel.com>
Date: Sun, 10 Mar 2019 09:23:29 +1030
Subject: [PATCH] added small vec test feature to quant_feat (didn't work
 well), and random bit error simulation feature to lpcnet_dec

---
 README.md        |  6 +++++-
 src/lpcnet_dec.c | 37 +++++++++++++++++++++++++++++++------
 src/quant_feat.c | 24 ++++++++++++++++++------
 3 files changed, 54 insertions(+), 13 deletions(-)

diff --git a/README.md b/README.md
index 6abaef5..8d6f38f 100644
--- a/README.md
+++ b/README.md
@@ -142,7 +142,11 @@ Same thing with everything integrated into stand alone encoder and decoder progr
 
 ```cat ~/Downloads/speech_orig_16k.s16 | ./lpcnet_enc | ./lpcnet_dec | aplay -f S16_LE -r 16000```
 
-The bit stream interface is 1 bit/char, as I find that convenient for my digital voice over radio experiments.  The decimation rate, number of VQ stages, and a few other parameters can be set as command line options. You'll need the same set of parameters for the encoder as decoder.
+The bit stream interface is 1 bit/char, as I find that convenient for my digital voice over radio experiments.  The decimation rate, number of VQ stages, and a few other parameters can be set as command line options, for example 20ms frame rate, 3 stage VQ (2050 bits/s):
+
+```cat ~/Downloads/speech_orig_16k.s16 | ./lpcnet_enc -d 2 -n 3 | ./lpcnet_dec -d 2 -n 3 | aplay -f S16_LE -r 16000```
+
+You'll need the same set of parameters for the encoder as decoder.
 
 Useful additions would be:
 
diff --git a/src/lpcnet_dec.c b/src/lpcnet_dec.c
index ab11e96..0ffae51 100644
--- a/src/lpcnet_dec.c
+++ b/src/lpcnet_dec.c
@@ -58,10 +58,12 @@ int main(int argc, char **argv) {
     int   mbest_survivors = 5;
     float weight = 1.0/sqrt(NB_BANDS);    
     int   pitch_bits = 6;
-
+    float ber = 0.0;
+    
     /* quantiser options */
     
     static struct option long_options[] = {
+        {"ber",        required_argument, 0, 'b'},
         {"decimate",   required_argument, 0, 'd'},
         {"numstages",  required_argument, 0, 'n'},
         {"pitchquant", required_argument, 0, 'o'},
@@ -73,8 +75,12 @@ int main(int argc, char **argv) {
     int   c;
     int opt_index = 0;
 
-    while ((c = getopt_long (argc, argv, "d:n:o:p:v", long_options, &opt_index)) != -1) {
+    while ((c = getopt_long (argc, argv, "b:d:n:o:p:v", long_options, &opt_index)) != -1) {
         switch (c) {
+        case 'b':
+            ber = atof(optarg);
+            fprintf(stderr, "BER = %f\n", ber);
+            break;
         case 'd':
             dec = atoi(optarg);
             fprintf(stderr, "dec = %d\n", dec);
@@ -94,8 +100,10 @@ int main(int argc, char **argv) {
         case 'v':
             lpcnet_verbose = 1;
             break;
-         default:
-            fprintf(stderr,"usage: %s [Options]:\n  [-d --decimation 1/2/3...]\n", argv[0]);
+        default:
+            fprintf(stderr,"usage: %s [Options]:\n", argv[0]);
+            fprintf(stderr,"  [-b --ber BER]\n");
+            fprintf(stderr,"  [-d --decimation 1/2/3...]\n");
             fprintf(stderr,"  [-n --numstages]\n  [-o --pitchbits nBits]\n");
             fprintf(stderr,"  [-p --pred predCoff]\n");
             fprintf(stderr,"  [-v --verbose]\n");
@@ -120,13 +128,27 @@ int main(int argc, char **argv) {
 
     fin = stdin;
     fout = stdout;
- 
+    int nbits = 0, nerrs = 0;
+
     do {
         float in_features[NB_TOTAL_FEATURES];
         float features[NB_TOTAL_FEATURES];
         short pcm[FRAME_SIZE];
-        if ((q->f % q->dec) == 0)
+        if ((q->f % q->dec) == 0) {
             bits_read = fread(frame, sizeof(char), q->bits_per_frame, fin);
+            nbits += bits_read;
+            if (ber != 0.0) {
+                int i;
+                for(i=0; i<q->bits_per_frame; i++) {
+                    float r = (float)rand()/RAND_MAX;
+                    if (r < ber) {
+                        frame[i] = (frame[i] ^ 1) & 0x1;
+                        nerrs++;
+                    }
+                }
+            }
+            
+        }
         lpcnet_frame_to_features(q, frame, in_features);
        
         RNN_COPY(features, in_features, NB_TOTAL_FEATURES);
@@ -139,5 +161,8 @@ int main(int argc, char **argv) {
     fclose(fin);
     fclose(fout);
     lpcnet_destroy(net); lpcnet_quant_destroy(q);
+
+    if (ber != 0.0)
+        fprintf(stderr, "nbits: %d nerr: %d BER: %4.3f\n", nbits, nerrs, (float)nerrs/nbits);
     return 0;
 }
diff --git a/src/quant_feat.c b/src/quant_feat.c
index 1ba4fd8..5a0cff2 100644
--- a/src/quant_feat.c
+++ b/src/quant_feat.c
@@ -61,10 +61,12 @@ int main(int argc, char *argv[]) {
     float weight = 1.0;    
     float pitch_gain_bias = 0.0;
     int   pitch_bits = 0;
-
+    int   small_vec = 0;
+    
     for(i=0; i<MAX_STAGES*NB_BANDS*MAX_ENTRIES; i++) vq[i] = 0.0;
     
     static struct option long_options[] = {
+        {"small",      required_argument, 0, 'a'},
         {"decimate",   required_argument, 0, 'd'},
         {"extpitch",   required_argument, 0, 'e'},
         {"first",      required_argument, 0, 'f'},
@@ -83,10 +85,14 @@ int main(int argc, char *argv[]) {
     };
 
     int opt_index = 0;
-
-    while ((c = getopt_long (argc, argv, "d:q:vs:f:p:e:u:l:m:h:wg:o:", long_options, &opt_index)) != -1) {
+    
+    while ((c = getopt_long (argc, argv, "ad:q:vs:f:p:e:u:l:m:h:wg:o:", long_options, &opt_index)) != -1) {
         switch (c) {
-        case 'f':
+        case 'a':
+            /* small cpectral vectors - zero out several bands */
+            small_vec = 1;
+            break;
+       case 'f':
             /* start VQ at band first+1 */
             first = atoi(optarg);
             k = NB_BANDS-first;
@@ -184,7 +190,7 @@ int main(int argc, char *argv[]) {
         }
     }
 
-    fprintf(stderr, "dec: %d pred: %3.2f num_stages: %d mbest: %d", dec, pred, num_stages, mbest_survivors);
+    fprintf(stderr, "dec: %d pred: %3.2f num_stages: %d mbest: %d small: %d", dec, pred, num_stages, mbest_survivors, small_vec);
     fprintf(stderr, "\n");
     
     /* delay line so we can pass some features (like pitch and voicing) through unmodified */
@@ -251,7 +257,7 @@ int main(int argc, char *argv[]) {
                 fprintf(stderr, "f: %d i: %d\n", f, i);
             }
         }
-        
+
         /* convert cepstrals to dB */
         for(i=0; i<NB_BANDS; i++)
             features[i] *= 10.0;
@@ -404,6 +410,12 @@ int main(int argc, char *argv[]) {
             }
         }
         
+        if (small_vec) {
+            /* zero out unused cepstrals in small vec mode */
+            for(i=12; i<NB_BANDS; i++)
+                features_out[i] = 0.0;
+        }
+        
         fwrite(features_out, sizeof(float), NB_FEATURES, fout);
         fflush(stdin);
         fflush(stdout);