Added a level indicator to new mixer.

webrtc/voice_engine/level_indicator.cc

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 10 matching lines @@
 // in the range of 0-32
 const int8_t permutation[33] =
     {0,1,2,3,4,4,5,5,5,5,6,6,6,6,6,7,7,7,7,8,8,8,9,9,9,9,9,9,9,9,9,9,9};
 
 
 AudioLevel::AudioLevel() :
     _absMax(0),
     _count(0),
     _currentLevel(0),
     _currentLevelFullRange(0) {
+  WebRtcSpl_Init();

[mflodman, 2016/08/18 09:34:13]

This has already been called in VoEBaseImpl::Init, should this really be done
here?

[aleloi, 2016/08/18 09:40:33]

I wanted to use the level indicator as a separate dependency in the new audio
mixer without having to depend on the whole of VoE. But then the mixer crashed
in unit tests, because the SPL functions (which this component uses) were not
initialized.

My understanding is that if this component is going to be a separate build
target, it should initialize its dependencies by itself.

[mflodman, 2016/08/18 09:45:28]

But is it ok to do this twice in the case you run this in VoiceEngine? Should
this rather be done in the test itself?

This might be right, but I don't know how SPLib initialization is supposed to
work and I think it's better if someone in the audio team looks at this then me.

[minyue-webrtc, 2016/08/18 09:53:08]

It reads that WebRtcSpl_Init() should be called only once (see below). so we
should not go wrong with it. But true, it should be called on a high level. If
possible, do it in the test?

https://cs.chromium.org/chromium/src/third_party/webrtc/common_audio/signal_p...

[kwiberg-webrtc, 2016/08/19 11:24:44]

No, it's implemented so that it should be safe to call multiple times, even from
several different threads.

 }
 
 AudioLevel::~AudioLevel() {
 }
 
 void AudioLevel::Clear()
 {
     rtc::CritScope cs(&_critSect);
     _absMax = 0;
     _count = 0;
@@ skipping 50 matching lines @@
 
 int16_t AudioLevel::LevelFullRange() const
 {
     rtc::CritScope cs(&_critSect);
     return _currentLevelFullRange;
 }
 
 }  // namespace voe
 
 }  // namespace webrtc