1 /* 2 * Copyright (c) 2013 The WebRTC project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 #ifndef WEBRTC_MODULES_AUDIO_DEVICE_ANDROID_AUDIO_TRACK_JNI_H_ 12 #define WEBRTC_MODULES_AUDIO_DEVICE_ANDROID_AUDIO_TRACK_JNI_H_ 13 14 #include <jni.h> 15 16 #include "webrtc/base/thread_checker.h" 17 #include "webrtc/modules/audio_device/android/audio_common.h" 18 #include "webrtc/modules/audio_device/android/audio_manager.h" 19 #include "webrtc/modules/audio_device/include/audio_device_defines.h" 20 #include "webrtc/modules/audio_device/audio_device_generic.h" 21 #include "webrtc/modules/utility/include/helpers_android.h" 22 #include "webrtc/modules/utility/include/jvm_android.h" 23 24 namespace webrtc { 25 26 // Implements 16-bit mono PCM audio output support for Android using the Java 27 // AudioTrack interface. Most of the work is done by its Java counterpart in 28 // WebRtcAudioTrack.java. This class is created and lives on a thread in 29 // C++-land, but decoded audio buffers are requested on a high-priority 30 // thread managed by the Java class. 31 // 32 // An instance must be created and destroyed on one and the same thread. 33 // All public methods must also be called on the same thread. A thread checker 34 // will RTC_DCHECK if any method is called on an invalid thread. 35 // 36 // This class uses AttachCurrentThreadIfNeeded to attach to a Java VM if needed 37 // and detach when the object goes out of scope. Additional thread checking 38 // guarantees that no other (possibly non attached) thread is used. 39 class AudioTrackJni { 40 public: 41 // Wraps the Java specific parts of the AudioTrackJni into one helper class. 42 class JavaAudioTrack { 43 public: 44 JavaAudioTrack(NativeRegistration* native_registration, 45 rtc::scoped_ptr<GlobalRef> audio_track); 46 ~JavaAudioTrack(); 47 48 void InitPlayout(int sample_rate, int channels); 49 bool StartPlayout(); 50 bool StopPlayout(); 51 bool SetStreamVolume(int volume); 52 int GetStreamMaxVolume(); 53 int GetStreamVolume(); 54 55 private: 56 rtc::scoped_ptr<GlobalRef> audio_track_; 57 jmethodID init_playout_; 58 jmethodID start_playout_; 59 jmethodID stop_playout_; 60 jmethodID set_stream_volume_; 61 jmethodID get_stream_max_volume_; 62 jmethodID get_stream_volume_; 63 }; 64 65 explicit AudioTrackJni(AudioManager* audio_manager); 66 ~AudioTrackJni(); 67 68 int32_t Init(); 69 int32_t Terminate(); 70 71 int32_t InitPlayout(); PlayoutIsInitialized()72 bool PlayoutIsInitialized() const { return initialized_; } 73 74 int32_t StartPlayout(); 75 int32_t StopPlayout(); Playing()76 bool Playing() const { return playing_; } 77 78 int SpeakerVolumeIsAvailable(bool& available); 79 int SetSpeakerVolume(uint32_t volume); 80 int SpeakerVolume(uint32_t& volume) const; 81 int MaxSpeakerVolume(uint32_t& max_volume) const; 82 int MinSpeakerVolume(uint32_t& min_volume) const; 83 84 void AttachAudioBuffer(AudioDeviceBuffer* audioBuffer); 85 86 private: 87 // Called from Java side so we can cache the address of the Java-manged 88 // |byte_buffer| in |direct_buffer_address_|. The size of the buffer 89 // is also stored in |direct_buffer_capacity_in_bytes_|. 90 // Called on the same thread as the creating thread. 91 static void JNICALL CacheDirectBufferAddress( 92 JNIEnv* env, jobject obj, jobject byte_buffer, jlong nativeAudioTrack); 93 void OnCacheDirectBufferAddress(JNIEnv* env, jobject byte_buffer); 94 95 // Called periodically by the Java based WebRtcAudioTrack object when 96 // playout has started. Each call indicates that |length| new bytes should 97 // be written to the memory area |direct_buffer_address_| for playout. 98 // This method is called on a high-priority thread from Java. The name of 99 // the thread is 'AudioTrackThread'. 100 static void JNICALL GetPlayoutData( 101 JNIEnv* env, jobject obj, jint length, jlong nativeAudioTrack); 102 void OnGetPlayoutData(size_t length); 103 104 // Stores thread ID in constructor. 105 rtc::ThreadChecker thread_checker_; 106 107 // Stores thread ID in first call to OnGetPlayoutData() from high-priority 108 // thread in Java. Detached during construction of this object. 109 rtc::ThreadChecker thread_checker_java_; 110 111 // Calls AttachCurrentThread() if this thread is not attached at construction. 112 // Also ensures that DetachCurrentThread() is called at destruction. 113 AttachCurrentThreadIfNeeded attach_thread_if_needed_; 114 115 // Wraps the JNI interface pointer and methods associated with it. 116 rtc::scoped_ptr<JNIEnvironment> j_environment_; 117 118 // Contains factory method for creating the Java object. 119 rtc::scoped_ptr<NativeRegistration> j_native_registration_; 120 121 // Wraps the Java specific parts of the AudioTrackJni class. 122 rtc::scoped_ptr<AudioTrackJni::JavaAudioTrack> j_audio_track_; 123 124 // Contains audio parameters provided to this class at construction by the 125 // AudioManager. 126 const AudioParameters audio_parameters_; 127 128 // Cached copy of address to direct audio buffer owned by |j_audio_track_|. 129 void* direct_buffer_address_; 130 131 // Number of bytes in the direct audio buffer owned by |j_audio_track_|. 132 size_t direct_buffer_capacity_in_bytes_; 133 134 // Number of audio frames per audio buffer. Each audio frame corresponds to 135 // one sample of PCM mono data at 16 bits per sample. Hence, each audio 136 // frame contains 2 bytes (given that the Java layer only supports mono). 137 // Example: 480 for 48000 Hz or 441 for 44100 Hz. 138 size_t frames_per_buffer_; 139 140 bool initialized_; 141 142 bool playing_; 143 144 // Raw pointer handle provided to us in AttachAudioBuffer(). Owned by the 145 // AudioDeviceModuleImpl class and called by AudioDeviceModuleImpl::Create(). 146 // The AudioDeviceBuffer is a member of the AudioDeviceModuleImpl instance 147 // and therefore outlives this object. 148 AudioDeviceBuffer* audio_device_buffer_; 149 }; 150 151 } // namespace webrtc 152 153 #endif // WEBRTC_MODULES_AUDIO_DEVICE_ANDROID_AUDIO_TRACK_JNI_H_ 154