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 MODULES_AUDIO_DEVICE_ANDROID_AUDIO_TRACK_JNI_H_ 12 #define MODULES_AUDIO_DEVICE_ANDROID_AUDIO_TRACK_JNI_H_ 13 14 #include <memory> 15 16 #include <jni.h> 17 18 #include "modules/audio_device/android/audio_common.h" 19 #include "modules/audio_device/android/audio_manager.h" 20 #include "modules/audio_device/audio_device_generic.h" 21 #include "modules/audio_device/include/audio_device_defines.h" 22 #include "modules/utility/include/helpers_android.h" 23 #include "modules/utility/include/jvm_android.h" 24 #include "rtc_base/thread_checker.h" 25 26 namespace webrtc { 27 28 // Implements 16-bit mono PCM audio output support for Android using the Java 29 // AudioTrack interface. Most of the work is done by its Java counterpart in 30 // WebRtcAudioTrack.java. This class is created and lives on a thread in 31 // C++-land, but decoded audio buffers are requested on a high-priority 32 // thread managed by the Java class. 33 // 34 // An instance must be created and destroyed on one and the same thread. 35 // All public methods must also be called on the same thread. A thread checker 36 // will RTC_DCHECK if any method is called on an invalid thread. 37 // 38 // This class uses AttachCurrentThreadIfNeeded to attach to a Java VM if needed 39 // and detach when the object goes out of scope. Additional thread checking 40 // guarantees that no other (possibly non attached) thread is used. 41 class AudioTrackJni { 42 public: 43 // Wraps the Java specific parts of the AudioTrackJni into one helper class. 44 class JavaAudioTrack { 45 public: 46 JavaAudioTrack(NativeRegistration* native_registration, 47 std::unique_ptr<GlobalRef> audio_track); 48 ~JavaAudioTrack(); 49 50 bool InitPlayout(int sample_rate, int channels); 51 bool StartPlayout(); 52 bool StopPlayout(); 53 bool SetStreamVolume(int volume); 54 int GetStreamMaxVolume(); 55 int GetStreamVolume(); 56 57 private: 58 std::unique_ptr<GlobalRef> audio_track_; 59 jmethodID init_playout_; 60 jmethodID start_playout_; 61 jmethodID stop_playout_; 62 jmethodID set_stream_volume_; 63 jmethodID get_stream_max_volume_; 64 jmethodID get_stream_volume_; 65 }; 66 67 explicit AudioTrackJni(AudioManager* audio_manager); 68 ~AudioTrackJni(); 69 70 int32_t Init(); 71 int32_t Terminate(); 72 73 int32_t InitPlayout(); PlayoutIsInitialized()74 bool PlayoutIsInitialized() const { return initialized_; } 75 76 int32_t StartPlayout(); 77 int32_t StopPlayout(); Playing()78 bool Playing() const { return playing_; } 79 80 int SpeakerVolumeIsAvailable(bool& available); 81 int SetSpeakerVolume(uint32_t volume); 82 int SpeakerVolume(uint32_t& volume) const; 83 int MaxSpeakerVolume(uint32_t& max_volume) const; 84 int MinSpeakerVolume(uint32_t& min_volume) const; 85 86 void AttachAudioBuffer(AudioDeviceBuffer* audioBuffer); 87 88 private: 89 // Called from Java side so we can cache the address of the Java-manged 90 // |byte_buffer| in |direct_buffer_address_|. The size of the buffer 91 // is also stored in |direct_buffer_capacity_in_bytes_|. 92 // Called on the same thread as the creating thread. 93 static void JNICALL CacheDirectBufferAddress( 94 JNIEnv* env, jobject obj, jobject byte_buffer, jlong nativeAudioTrack); 95 void OnCacheDirectBufferAddress(JNIEnv* env, jobject byte_buffer); 96 97 // Called periodically by the Java based WebRtcAudioTrack object when 98 // playout has started. Each call indicates that |length| new bytes should 99 // be written to the memory area |direct_buffer_address_| for playout. 100 // This method is called on a high-priority thread from Java. The name of 101 // the thread is 'AudioTrackThread'. 102 static void JNICALL GetPlayoutData( 103 JNIEnv* env, jobject obj, jint length, jlong nativeAudioTrack); 104 void OnGetPlayoutData(size_t length); 105 106 // Stores thread ID in constructor. 107 rtc::ThreadChecker thread_checker_; 108 109 // Stores thread ID in first call to OnGetPlayoutData() from high-priority 110 // thread in Java. Detached during construction of this object. 111 rtc::ThreadChecker thread_checker_java_; 112 113 // Calls AttachCurrentThread() if this thread is not attached at construction. 114 // Also ensures that DetachCurrentThread() is called at destruction. 115 AttachCurrentThreadIfNeeded attach_thread_if_needed_; 116 117 // Wraps the JNI interface pointer and methods associated with it. 118 std::unique_ptr<JNIEnvironment> j_environment_; 119 120 // Contains factory method for creating the Java object. 121 std::unique_ptr<NativeRegistration> j_native_registration_; 122 123 // Wraps the Java specific parts of the AudioTrackJni class. 124 std::unique_ptr<AudioTrackJni::JavaAudioTrack> j_audio_track_; 125 126 // Contains audio parameters provided to this class at construction by the 127 // AudioManager. 128 const AudioParameters audio_parameters_; 129 130 // Cached copy of address to direct audio buffer owned by |j_audio_track_|. 131 void* direct_buffer_address_; 132 133 // Number of bytes in the direct audio buffer owned by |j_audio_track_|. 134 size_t direct_buffer_capacity_in_bytes_; 135 136 // Number of audio frames per audio buffer. Each audio frame corresponds to 137 // one sample of PCM mono data at 16 bits per sample. Hence, each audio 138 // frame contains 2 bytes (given that the Java layer only supports mono). 139 // Example: 480 for 48000 Hz or 441 for 44100 Hz. 140 size_t frames_per_buffer_; 141 142 bool initialized_; 143 144 bool playing_; 145 146 // Raw pointer handle provided to us in AttachAudioBuffer(). Owned by the 147 // AudioDeviceModuleImpl class and called by AudioDeviceModule::Create(). 148 // The AudioDeviceBuffer is a member of the AudioDeviceModuleImpl instance 149 // and therefore outlives this object. 150 AudioDeviceBuffer* audio_device_buffer_; 151 }; 152 153 } // namespace webrtc 154 155 #endif // MODULES_AUDIO_DEVICE_ANDROID_AUDIO_TRACK_JNI_H_ 156