Fix normalization of noise estimate in NoiseSuppressor

webrtc/modules/audio_processing/ns/noise_suppression_x.h

Index: webrtc/modules/audio_processing/ns/noise_suppression_x.h
diff --git a/webrtc/modules/audio_processing/ns/noise_suppression_x.h b/webrtc/modules/audio_processing/ns/noise_suppression_x.h
index 7a5fc428c16cd34a8beef4967558b3b99da69838..9f7df197fb838abd74c005d5dcb710d6bffea868 100644
--- a/webrtc/modules/audio_processing/ns/noise_suppression_x.h
+++ b/webrtc/modules/audio_processing/ns/noise_suppression_x.h
@@ -88,12 +88,15 @@ void WebRtcNsx_Process(NsxHandle* nsxInst,
  *
  * Input
  *      - nsxInst       : NSx instance. Needs to be initiated before call.
+ *      - domain        : Domain of the noise estimate, which is the number of

[peah-webrtc, 2016/03/31 20:50:57]

Why is this called domain? It is the Q-value, right? I think that it would be
more clear just to call it something with Q (Q_noise or something similar).

[aluebs-webrtc, 2016/04/01 01:52:42]

I couldn't come up with a better naming, but I agree it is not clear. It is in
fact the q-value. Accepted your suggestion.

+ *                        bits that it needs to be right-shifted to be
+ *                        normalized.
  *
  * Return value         : Pointer to the noise estimate per frequency bin.
  *                        Returns NULL if the input is a NULL pointer or an
  *                        uninitialized instance.
  */
-const uint32_t* WebRtcNsx_noise_estimate(const NsxHandle* nsxInst);
+const uint32_t* WebRtcNsx_noise_estimate(const NsxHandle* nsxInst, int* domain);

[peah-webrtc, 2016/03/31 20:50:57]

I think it is great to both get the spectrum and the Q value at the same time,
but it is a bit confusing having them returned in different ways in the function
call.

[aluebs-webrtc, 2016/04/01 01:52:42]

As I said in turaj's comment, I also find this way of returning things slightly
confusing, but I see how it forces the user to not forget about normalizing. I
can go back to my original solution of having a separate API for the q-value if
you want, but it is hard to make all reviewers happy when they have opposite
opinions. If you have a better idea, please suggest a specific solution, but
keep in mind that this is a C (not C++) file.

 
 /* Returns the number of frequency bins, which is the length of the noise
  * estimate for example.