commit a8e2a2b1a8ab2cb9d9e7d4fe21128ac9e769fe4e
author Jean-Marc Valin <jmvalin@jmvalin.ca> Wed Sep 26 22:57:36 2018 -0400
committer Jean-Marc Valin <jmvalin@jmvalin.ca> Wed Sep 26 22:57:36 2018 -0400
tree c7d4ae16e50f6a8e08ef6af599579be9dc4b14fe
parent 5d290239f110af41f1e29b63b8008b5016e23a63

Prevent the SILK counter from overflowing after 2 years and 9 months

or "just" 1 year and 4 months for 10-ms frames.
The overflow can eventually cause a divide-by-zero when counter == -16

Thanks to Dmitry Malinin for reporting the bug.

silk/VAD.c

diff --git a/silk/VAD.c b/silk/VAD.c
index 541e505..d0cda52 100644
--- a/silk/VAD.c
+++ b/silk/VAD.c
@@ -312,6 +312,8 @@
     /* Initially faster smoothing */
     if( psSilk_VAD->counter < 1000 ) { /* 1000 = 20 sec */
         min_coef = silk_DIV32_16( silk_int16_MAX, silk_RSHIFT( psSilk_VAD->counter, 4 ) + 1 );
+        /* Increment frame counter */
+        psSilk_VAD->counter++;
     } else {
         min_coef = 0;
     }
@@ -355,7 +357,4 @@
         /* Store as part of state */
         psSilk_VAD->NL[ k ] = nl;
     }
-
-    /* Increment frame counter */
-    psSilk_VAD->counter++;
 }