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 <jni.h> 15 16 #include <memory> 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 JvmThreadConnector 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 jmethodID get_buffer_size_in_frames_; 66 }; 67 68 explicit AudioTrackJni(AudioManager* audio_manager); 69 ~AudioTrackJni(); 70 71 int32_t Init(); 72 int32_t Terminate(); 73 74 int32_t InitPlayout(); PlayoutIsInitialized()75 bool PlayoutIsInitialized() const { return initialized_; } 76 77 int32_t StartPlayout(); 78 int32_t StopPlayout(); Playing()79 bool Playing() const { return playing_; } 80 81 int SpeakerVolumeIsAvailable(bool& available); 82 int SetSpeakerVolume(uint32_t volume); 83 int SpeakerVolume(uint32_t& volume) const; 84 int MaxSpeakerVolume(uint32_t& max_volume) const; 85 int MinSpeakerVolume(uint32_t& min_volume) const; 86 87 void AttachAudioBuffer(AudioDeviceBuffer* audioBuffer); 88 89 private: 90 // Called from Java side so we can cache the address of the Java-manged 91 // |byte_buffer| in |direct_buffer_address_|. The size of the buffer 92 // is also stored in |direct_buffer_capacity_in_bytes_|. 93 // Called on the same thread as the creating thread. 94 static void JNICALL CacheDirectBufferAddress(JNIEnv* env, 95 jobject obj, 96 jobject byte_buffer, 97 jlong nativeAudioTrack); 98 void OnCacheDirectBufferAddress(JNIEnv* env, jobject byte_buffer); 99 100 // Called periodically by the Java based WebRtcAudioTrack object when 101 // playout has started. Each call indicates that |length| new bytes should 102 // be written to the memory area |direct_buffer_address_| for playout. 103 // This method is called on a high-priority thread from Java. The name of 104 // the thread is 'AudioTrackThread'. 105 static void JNICALL GetPlayoutData(JNIEnv* env, 106 jobject obj, 107 jint length, 108 jlong nativeAudioTrack); 109 void OnGetPlayoutData(size_t length); 110 111 // Stores thread ID in constructor. 112 rtc::ThreadChecker thread_checker_; 113 114 // Stores thread ID in first call to OnGetPlayoutData() from high-priority 115 // thread in Java. Detached during construction of this object. 116 rtc::ThreadChecker thread_checker_java_; 117 118 // Calls JavaVM::AttachCurrentThread() if this thread is not attached at 119 // construction. 120 // Also ensures that DetachCurrentThread() is called at destruction. 121 JvmThreadConnector attach_thread_if_needed_; 122 123 // Wraps the JNI interface pointer and methods associated with it. 124 std::unique_ptr<JNIEnvironment> j_environment_; 125 126 // Contains factory method for creating the Java object. 127 std::unique_ptr<NativeRegistration> j_native_registration_; 128 129 // Wraps the Java specific parts of the AudioTrackJni class. 130 std::unique_ptr<AudioTrackJni::JavaAudioTrack> j_audio_track_; 131 132 // Contains audio parameters provided to this class at construction by the 133 // AudioManager. 134 const AudioParameters audio_parameters_; 135 136 // Cached copy of address to direct audio buffer owned by |j_audio_track_|. 137 void* direct_buffer_address_; 138 139 // Number of bytes in the direct audio buffer owned by |j_audio_track_|. 140 size_t direct_buffer_capacity_in_bytes_; 141 142 // Number of audio frames per audio buffer. Each audio frame corresponds to 143 // one sample of PCM mono data at 16 bits per sample. Hence, each audio 144 // frame contains 2 bytes (given that the Java layer only supports mono). 145 // Example: 480 for 48000 Hz or 441 for 44100 Hz. 146 size_t frames_per_buffer_; 147 148 bool initialized_; 149 150 bool playing_; 151 152 // Raw pointer handle provided to us in AttachAudioBuffer(). Owned by the 153 // AudioDeviceModuleImpl class and called by AudioDeviceModule::Create(). 154 // The AudioDeviceBuffer is a member of the AudioDeviceModuleImpl instance 155 // and therefore outlives this object. 156 AudioDeviceBuffer* audio_device_buffer_; 157 }; 158 159 } // namespace webrtc 160 161 #endif // MODULES_AUDIO_DEVICE_ANDROID_AUDIO_TRACK_JNI_H_ 162