Deactivated the intelligibility enhancement functionality by default

webrtc/media/engine/webrtcvoiceengine.cc

Index: webrtc/media/engine/webrtcvoiceengine.cc
diff --git a/webrtc/media/engine/webrtcvoiceengine.cc b/webrtc/media/engine/webrtcvoiceengine.cc
index a61b8c42844efe67dc7109534080b9036a26a62b..d0ca9aea617322719caf5cf0184c92128e25cb07 100644
--- a/webrtc/media/engine/webrtcvoiceengine.cc
+++ b/webrtc/media/engine/webrtcvoiceengine.cc
@@ -64,6 +64,14 @@ const int kDefaultAudioDeviceId = 0;
 
 constexpr int kNackRtpHistoryMs = 5000;
 
+// Check to verify that the define for the intelligibility enhancer is properly
+// set.
+#if !defined(WEBRTC_INTELLIGIBILITY_ENHANCER) || \

[the sun, 2016/08/26 12:08:56]

Why not just
#if WEBRTC_INTELLIGIBILITY_ENHANCER
?
(unset defaults to 0)

[kjellander_webrtc, 2016/08/26 12:52:01]

I think there was a similar discussion for an AEC define and there was a good
reason for having it set to 0 or 1. I can't recall exactly why it was safer
though.

[peah-webrtc, 2016/08/26 13:09:43]

The reason was it is up to the build system to distribute the defines. And if
that is missed in some place, that will be a silent error as the define then
defaults to 0.

The construct here is not perfect either, but it at least requires the define to
be explicitly set.

In this case, I think nothing can go bad at runtime during this, but the code
may evolve and therefore I'd prefer to have it like this.

[peah-webrtc, 2016/08/26 13:09:43]

The reason behind that is that this is a define that spans several subunits in
the build system, and doing the check like this ensures that it is explicitly
defined everywhere. 

This is to avoid previous errors where the define was set to 1 in some places
but was not specified in other places without any warning thereof.

[the sun, 2016/08/26 13:17:48]

Does it have to be like that then? Could it be set up in one place in the build
files?

Even if you make sure it is set explicitly, it may still be set differently.

+    (WEBRTC_INTELLIGIBILITY_ENHANCER != 0 &&     \
+     WEBRTC_INTELLIGIBILITY_ENHANCER != 1)
+#error "Set WEBRTC_INTELLIGIBILITY_ENHANCER to either 0 or 1"
+#endif
+
 // Codec parameters for Opus.
 // draft-spittka-payload-rtp-opus-03
 
@@ -649,6 +657,11 @@ bool WebRtcVoiceEngine::ApplyOptions(const AudioOptions& options_in) {
   }
 #endif
 
+#if (WEBRTC_INTELLIGIBILITY_ENHANCER == 0)
+  // Hardcode the intelligibility enhancer to be off.
+  options.intelligibility_enhancer = rtc::Optional<bool>(false);
+#endif
+
   webrtc::VoEAudioProcessing* voep = voe_wrapper_->processing();
 
   if (options.echo_cancellation) {