Improves stereo/mono audio support on Android

webrtc/modules/audio_device/android/opensles_player.cc

 /*
  *  Copyright (c) 2015 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 61 matching lines @@
   RTC_DCHECK(!engine_);
   RTC_DCHECK(!output_mix_.Get());
   RTC_DCHECK(!player_);
   RTC_DCHECK(!simple_buffer_queue_);
   RTC_DCHECK(!volume_);
 }
 
 int OpenSLESPlayer::Init() {
   ALOGD("Init%s", GetThreadInfo().c_str());
   RTC_DCHECK(thread_checker_.CalledOnValidThread());
+  if (audio_parameters_.channels() == 2) {
+    // TODO(henrika): FineAudioBuffer needs more work to support stereo.
+    ALOGE("OpenSLESPlayer does not support stereo");
+    return -1;
+  }
   return 0;
 }
 
 int OpenSLESPlayer::Terminate() {
   ALOGD("Terminate%s", GetThreadInfo().c_str());
   RTC_DCHECK(thread_checker_.CalledOnValidThread());
   StopPlayout();
   return 0;
 }
 
@@ skipping 324 matching lines @@
   RTC_DCHECK(player_);
   SLuint32 state;
   SLresult err = (*player_)->GetPlayState(player_, &state);
   if (SL_RESULT_SUCCESS != err) {
     ALOGE("GetPlayState failed: %d", err);
   }
   return state;
 }
 
 }  // namespace webrtc