Adding AudioDeviceDataObserver interface

webrtc/voice_engine/voe_base_impl.cc

Index: webrtc/voice_engine/voe_base_impl.cc
diff --git a/webrtc/voice_engine/voe_base_impl.cc b/webrtc/voice_engine/voe_base_impl.cc
index 5a037bf8ca9fa395756f8ab4632996572cd9757b..904e4b82afe0962ad37040e93292c15d5c401c3d 100644
--- a/webrtc/voice_engine/voe_base_impl.cc
+++ b/webrtc/voice_engine/voe_base_impl.cc
@@ -8,6 +8,9 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
+#include <string>
+#include <algorithm>
+
 #include "webrtc/voice_engine/voe_base_impl.h"
 
 #include "webrtc/api/audio_codecs/builtin_audio_decoder_factory.h"
@@ -228,13 +231,6 @@ int VoEBaseImpl::Init(
         "Init() failed to register event observer for the ADM");
   }
 
-  // Register the AudioTransport implementation

[the sun, 2017/03/21 21:42:50]

You shouldn't need to move this. Setting the audio callback on an ADM which is
already delivering media is not supported by the default ADM implementation.
See:

https://chromium.googlesource.com/external/webrtc/+/master/webrtc/modules/aud...
and
https://chromium.googlesource.com/external/webrtc/+/master/webrtc/modules/aud...

(sadly, the interface does not mention this limitation)

[lliuu, 2017/03/22 18:50:30]

Oh I see, then the crashing bug should be fixed on client side. Thanks for the
clarification!!

-  if (shared_->audio_device()->RegisterAudioCallback(this) != 0) {
-    shared_->SetLastError(
-        VE_AUDIO_DEVICE_MODULE_ERROR, kTraceWarning,
-        "Init() failed to register audio callback for the ADM");
-  }
-
   // ADM initialization
   if (shared_->audio_device()->Init() != 0) {
     shared_->SetLastError(VE_AUDIO_DEVICE_MODULE_ERROR, kTraceError,
@@ -297,6 +293,15 @@ int VoEBaseImpl::Init(
   }
   shared_->set_audio_processing(audioproc);
 
+  // Register the AudioTransport implementation
+  // This needs to be called after audio processing module is set
+  // to avoid potential crashes.
+  if (shared_->audio_device()->RegisterAudioCallback(this) != 0) {
+    shared_->SetLastError(
+        VE_AUDIO_DEVICE_MODULE_ERROR, kTraceWarning,
+        "Init() failed to register audio callback for the ADM");
+  }
+
   // Set the error state for any failures in this block.
   shared_->SetLastError(VE_APM_ERROR);
   // Configure AudioProcessing components.