Adding AudioDeviceDataObserver interface

webrtc/voice_engine/voe_base_impl.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.
  */
 
+#include <string>
+#include <algorithm>
+
 #include "webrtc/voice_engine/voe_base_impl.h"
 
 #include "webrtc/api/audio_codecs/builtin_audio_decoder_factory.h"
 #include "webrtc/base/format_macros.h"
 #include "webrtc/base/logging.h"
 #include "webrtc/common_audio/signal_processing/include/signal_processing_library.h"
 #include "webrtc/modules/audio_coding/include/audio_coding_module.h"
 #include "webrtc/modules/audio_device/audio_device_impl.h"
 #include "webrtc/modules/audio_processing/include/audio_processing.h"
 #include "webrtc/system_wrappers/include/file_wrapper.h"
@@ skipping 200 matching lines @@
   // --------------------
   // Reinitialize the ADM
 
   // Register the AudioObserver implementation
   if (shared_->audio_device()->RegisterEventObserver(this) != 0) {
     shared_->SetLastError(
         VE_AUDIO_DEVICE_MODULE_ERROR, kTraceWarning,
         "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,
                           "Init() failed to initialize the ADM");
     return -1;
   }
 
   // Initialize the default speaker
   if (shared_->audio_device()->SetPlayoutDevice(
           WEBRTC_VOICE_ENGINE_DEFAULT_DEVICE) != 0) {
@@ skipping 42 matching lines @@
   if (!audioproc) {
     audioproc = AudioProcessing::Create();
     if (!audioproc) {
       LOG(LS_ERROR) << "Failed to create AudioProcessing.";
       shared_->SetLastError(VE_NO_MEMORY);
       return -1;
     }
   }
   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.
   if (audioproc->high_pass_filter()->Enable(true) != 0) {
     LOG_F(LS_ERROR) << "Failed to enable high pass filter.";
     return -1;
   }
   if (audioproc->echo_cancellation()->enable_drift_compensation(false) != 0) {
     LOG_F(LS_ERROR) << "Failed to disable drift compensation.";
     return -1;
@@ skipping 456 matching lines @@
     shared_->SetLastError(VE_CHANNEL_NOT_VALID, kTraceError,
         "AssociateSendChannel() failed to locate accociate_send_channel");
     return -1;
   }
 
   channel_ptr->set_associate_send_channel(ch);
   return 0;
 }
 
 }  // namespace webrtc