TWCC-PLR -based FecController doesn’t need smoothing

webrtc/common_audio/smoothing_filter.h

Index: webrtc/common_audio/smoothing_filter.h
diff --git a/webrtc/common_audio/smoothing_filter.h b/webrtc/common_audio/smoothing_filter.h
index 4a0efd99b6d5fa605a5e82c3157a638b449d0636..85adb8fb51963cbf5ee52c5c347d8d00f53d0b47 100644
--- a/webrtc/common_audio/smoothing_filter.h
+++ b/webrtc/common_audio/smoothing_filter.h
@@ -68,6 +68,18 @@ class SmoothingFilterImpl final : public SmoothingFilter {
   RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(SmoothingFilterImpl);
 };
 
+class NullSmoothingFilter final : public SmoothingFilter {

[minyue-webrtc, 2017/03/22 09:40:55]

can we move NullSmoothingFilter to fec controller
? It is very special and used only there.

[elad.alon_webrtc.org, 2017/03/22 10:14:25]

That's possible. On the other hand, what if somebody else reinvents it in
another file, because it wasn't very visible? Or if someone else needs it, he
would have to move it here. Wouldn't it be best to keep it here to begin with?

+ public:
+  NullSmoothingFilter();
+  ~NullSmoothingFilter() override;
+  void AddSample(float sample) override;
+  rtc::Optional<float> GetAverage() override;
+  bool SetTimeConstantMs(int time_constant_ms) override;
+
+ private:
+  rtc::Optional<float> last_sample_;
+};
+
 }  // namespace webrtc
 
 #endif  // WEBRTC_COMMON_AUDIO_SMOOTHING_FILTER_H_