Adds stereo support for Java-based input and output audio on Android

webrtc/modules/audio_device/android/audio_track_jni.cc

 /*
  *  Copyright (c) 2013 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 56 matching lines @@
   return audio_track_->CallIntMethod(get_stream_volume_);
 }
 
 // TODO(henrika): possible extend usage of AudioManager and add it as member.
 AudioTrackJni::AudioTrackJni(AudioManager* audio_manager)
     : j_environment_(JVM::GetInstance()->environment()),
       audio_parameters_(audio_manager->GetPlayoutAudioParameters()),
       direct_buffer_address_(nullptr),
       direct_buffer_capacity_in_bytes_(0),
       frames_per_buffer_(0),
+      bytes_per_frame_(0),
       initialized_(false),
       playing_(false),
       audio_device_buffer_(nullptr) {
   ALOGD("ctor%s", GetThreadInfo().c_str());
   RTC_DCHECK(audio_parameters_.is_valid());
   RTC_CHECK(j_environment_);
   JNINativeMethod native_methods[] = {
       {"nativeCacheDirectBufferAddress", "(Ljava/nio/ByteBuffer;J)V",
       reinterpret_cast<void*>(
           &webrtc::AudioTrackJni::CacheDirectBufferAddress)},
@@ skipping 133 matching lines @@
 void AudioTrackJni::OnCacheDirectBufferAddress(
     JNIEnv* env, jobject byte_buffer) {
   ALOGD("OnCacheDirectBufferAddress");
   RTC_DCHECK(thread_checker_.CalledOnValidThread());
   RTC_DCHECK(!direct_buffer_address_);
   direct_buffer_address_ =
       env->GetDirectBufferAddress(byte_buffer);
   jlong capacity = env->GetDirectBufferCapacity(byte_buffer);
   ALOGD("direct buffer capacity: %lld", capacity);
   direct_buffer_capacity_in_bytes_ = static_cast<size_t>(capacity);
-  frames_per_buffer_ = direct_buffer_capacity_in_bytes_ / kBytesPerFrame;
+  bytes_per_frame_ = audio_parameters_.channels() * sizeof(int16_t);
+  frames_per_buffer_ = direct_buffer_capacity_in_bytes_ / bytes_per_frame_;
   ALOGD("frames_per_buffer: %" PRIuS, frames_per_buffer_);
 }
 
 void JNICALL AudioTrackJni::GetPlayoutData(
   JNIEnv* env, jobject obj, jint length, jlong nativeAudioTrack) {
   webrtc::AudioTrackJni* this_object =
       reinterpret_cast<webrtc::AudioTrackJni*> (nativeAudioTrack);
   this_object->OnGetPlayoutData(static_cast<size_t>(length));
 }
 
 // This method is called on a high-priority thread from Java. The name of
 // the thread is 'AudioRecordTrack'.
 void AudioTrackJni::OnGetPlayoutData(size_t length) {
   RTC_DCHECK(thread_checker_java_.CalledOnValidThread());
-  RTC_DCHECK_EQ(frames_per_buffer_, length / kBytesPerFrame);
+  RTC_DCHECK_EQ(frames_per_buffer_, length / bytes_per_frame_);
   if (!audio_device_buffer_) {
     ALOGE("AttachAudioBuffer has not been called!");
     return;
   }
   // Pull decoded data (in 16-bit PCM format) from jitter buffer.
   int samples = audio_device_buffer_->RequestPlayoutData(frames_per_buffer_);
   if (samples <= 0) {
     ALOGE("AudioDeviceBuffer::RequestPlayoutData failed!");
     return;
   }
   RTC_DCHECK_EQ(static_cast<size_t>(samples), frames_per_buffer_);
   // Copy decoded data into common byte buffer to ensure that it can be
   // written to the Java based audio track.
   samples = audio_device_buffer_->GetPlayoutData(direct_buffer_address_);
-  RTC_DCHECK_EQ(length, kBytesPerFrame * samples);
+  RTC_DCHECK_EQ(length, bytes_per_frame_ * samples);
 }
 
 }  // namespace webrtc