commit cc2bf69bef8040dcfaf40a13c75248c84210ea9d
author Jean-Marc Valin <jmvalin@jmvalin.ca> Fri Feb 16 12:36:44 2018 -0500
committer Jean-Marc Valin <jmvalin@jmvalin.ca> Fri Feb 16 12:38:15 2018 -0500
tree e04b0341fa33b81cbc68e3a1941af9bdc06eadc6
parent daf9503472faad50a49e03ccda0f840d8261f4c1

Fixes integer overflow in SILK VAD for 10-ms frames

Reported by Chandrakala Madhira on the mailing list

silk/VAD.c

diff --git a/silk/VAD.c b/silk/VAD.c
index 0a782af..678061d 100644
--- a/silk/VAD.c
+++ b/silk/VAD.c
@@ -252,15 +252,14 @@
         speech_nrg += ( b + 1 ) * silk_RSHIFT( Xnrg[ b ] - psSilk_VAD->NL[ b ], 4 );
     }
 
+    if( psEncC->frame_length == 20 * psEncC->fs_kHz ) {
+        speech_nrg = silk_RSHIFT32( speech_nrg, 1 );
+    }
     /* Power scaling */
     if( speech_nrg <= 0 ) {
         SA_Q15 = silk_RSHIFT( SA_Q15, 1 );
-    } else if( speech_nrg < 32768 ) {
-        if( psEncC->frame_length == 10 * psEncC->fs_kHz ) {
-            speech_nrg = silk_LSHIFT_SAT32( speech_nrg, 16 );
-        } else {
-            speech_nrg = silk_LSHIFT_SAT32( speech_nrg, 15 );
-        }
+    } else if( speech_nrg < 16384 ) {
+        speech_nrg = silk_LSHIFT_SAT32( speech_nrg, 16 );
 
         /* square-root */
         speech_nrg = silk_SQRT_APPROX( speech_nrg );