Add lossgen_demo

Also skip the first loss values being generated since they're
biased towards "not lost" due to the initialization.

Author: jmvalin

Makefile.am

@@ -308,8 +308,16 @@ endif
 if ENABLE_DRED
 TESTS += tests/test_opus_dred
 endif
+
+if ENABLE_LOSSGEN
+noinst_PROGRAMS += lossgen_demo
+lossgen_demo_SOURCES = dnn/lossgen_demo.c $(LOSSGEN_SOURCES)
+lossgen_demo_LDADD = $(LIBM)
 endif
 
+endif
+
+
 EXTRA_DIST = opus.pc.in \
              opus-uninstalled.pc.in \
              opus.m4 \

dnn/lossgen.c

@@ -70,7 +70,7 @@ void compute_generic_dense_lossgen(const LinearLayer *layer, float *output, cons
 }
 
 
-int sample_loss(
+static int sample_loss_impl(
     LossGenState *st,
     float percent_loss)
 {
@@ -90,6 +90,19 @@ int sample_loss(
   return loss;
 }
 
+int sample_loss(
+    LossGenState *st,
+    float percent_loss)
+{
+   /* Due to GRU being initialized with zeros, the first packets aren't quite random,
+      so we skip them. */
+   if (!st->used) {
+      int i;
+      for (i=0;i<100;i++) sample_loss_impl(st, percent_loss);
+      st->used = 1;
+   }
+   return sample_loss_impl(st, percent_loss);
+}
 
 void lossgen_init(LossGenState *st)
 {

dnn/lossgen.h

@@ -15,6 +15,7 @@ typedef struct {
   float gru1_state[LOSSGEN_GRU1_STATE_SIZE];
   float gru2_state[LOSSGEN_GRU2_STATE_SIZE];
   int last_loss;
+  int used;
 } LossGenState;
 
 

dnn/lossgen_demo.c

@@ -0,0 +1,22 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include "lossgen.h"
+int main(int argc, char **argv)
+{
+   LossGenState st;
+   long num_packets;
+   long i;
+   float percent;
+   if (argc != 3) {
+      fprintf(stderr, "usage: %s <percent_loss> <nb packets>\n", argv[0]);
+      return 1;
+   }
+   lossgen_init(&st);
+   percent = atof(argv[1]);
+   num_packets = atol(argv[2]);
+   /*printf("loss: %f %d\n", percent, num_packets);*/
+   for (i=0;i<num_packets;i++) {
+      printf("%d\n", sample_loss(&st, percent*0.01f));
+   }
+   return 0;
+}