Fix for left-shift of potentially negative values in NetEq.

webrtc/modules/audio_coding/neteq/expand.cc

Index: webrtc/modules/audio_coding/neteq/expand.cc
diff --git a/webrtc/modules/audio_coding/neteq/expand.cc b/webrtc/modules/audio_coding/neteq/expand.cc
index da870d77064c559fcf6d7e5541ca1a50a7a5bf88..40b1cba11fc21a1dfa1c723d1ce7d58dd556fee3 100644
--- a/webrtc/modules/audio_coding/neteq/expand.cc
+++ b/webrtc/modules/audio_coding/neteq/expand.cc
@@ -441,7 +441,7 @@ void Expand::AnalyzeSignal(int16_t* random_vector) {
   for (size_t i = 0; i < kNumCorrelationCandidates; ++i) {
     int32_t ratio;
     if (best_distortion[i] > 0) {
-      ratio = (best_correlation[i] << 16) / best_distortion[i];
+      ratio = (best_correlation[i] * 65536) / best_distortion[i];

[kwiberg-webrtc, 2017/01/09 14:07:13]

Since larger powers of two have lots of digits that one can get wrong (and that
not everyone has memorized), I've found it useful to write this sort of thing
like this instead:

  ratio = (best_correlation[i] * (1 << 16)) / best_distortion[i];

[hlundin-webrtc, 2017/01/09 14:12:07]

Acknowledged.

[ivoc, 2017/01/09 14:39:53]

Good idea, done.

     } else if (best_correlation[i] == 0) {
       ratio = 0;  // No correlation set result to zero.
     } else {