Android Audio Architecture 圖如下所示
詳細(xì)調(diào)用路徑如下
1. 音頻播放
示例代碼
MediaPlayer mp = new MediaPlayer();
mp.setDataSource(PATH_TO_FILE);
mp.prepare();
mp.start();
1.1 MediaPlayer mp = new MediaPlayer()
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函數(shù)調(diào)用
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文件
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MediaPlayer:: MediaPlayer
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MediaPlayer.Java
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MediaPlayer::native_setup
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MediaPlayer.Java
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android_media_MediaPlayer_native_setup
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android_media_MediaPlayer.cpp
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MediaPlayer::MediaPlayer
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MediaPlayer.cpp
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1.2 mp.setDataSource(PATH_TO_FILE)
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函數(shù)調(diào)用
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文件
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MediaPlayer:: setDataSource
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MediaPlayer.Java
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MediaPlayer::setDataSource
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MediaPlayer.Java
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android_media_MediaPlayer_setDataSource
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android_media_MediaPlayer.cpp
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MediaPlayer:: setDataSource
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MediaPlayer.cpp
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MediaPlayer::getMediaPlayerService
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MediaPlayer.cpp
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IMediaPlayerService
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IMediaPlayerService.h
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MediaPlayerService:: MediaPlayerService[f1]
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MediaPlayerService.cpp
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MediaPlayerService::create
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MediaPlayerService.cpp
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MediaPlayerService::Client::Client
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MediaPlayerService.cpp
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MediaPlayerService::Client::setDataSource
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MediaPlayerService.cpp
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getPlayerType[f2]
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MediaPlayerService.cpp
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MediaPlayerService::Client::createPlayer
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MediaPlayerService.cpp
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createPlayer
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MediaPlayerService.cpp
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PVPlayer
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PVPlayer.h
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MidiFile
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MidiFile.cpp
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VorbisPlayer
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VorbisPlayer.cpp
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AudioOutput::AudioOutput
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MediaPlayerService.cpp
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1.3 mp.prepare()
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函數(shù)調(diào)用
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文件
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MediaPlayer:: prepare
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MediaPlayer.Java
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MediaPlayer:: prepare
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MediaPlayer.Java
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android_media_MediaPlayer_ prepare
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android_media_MediaPlayer.cpp
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MediaPlayer:: prepare
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MediaPlayer.cpp
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PVPlayer:: prepare
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PVPlayer.h
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MidiFile:: prepare
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MidiFile.cpp
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VorbisPlayer:: prepare
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VorbisPlayer.cpp
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VorbisPlayer::createOutputTrack
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VorbisPlayer.cpp
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AudioOutput::open
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MediaPlayerService.cpp
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AudioTrack::AudioTrack
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AudioTrack.cpp
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AudioSystem::get_audio_flinger
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AudioSystem.cpp
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AudioFlinger::createTrack
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AudioFlinger.cpp
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1.4 mp.start()
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函數(shù)調(diào)用
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文件
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MediaPlayer:: start
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MediaPlayer.Java
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MediaPlayer:: start
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MediaPlayer.Java
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android_media_MediaPlayer_ start
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android_media_MediaPlayer.cpp
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MediaPlayer:: start
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MediaPlayer.cpp
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PVPlayer:: start
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PVPlayer.h
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MidiFile:: p start
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MidiFile.cpp
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VorbisPlayer:: start
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VorbisPlayer.cpp
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AudioTrack::start
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AudioTrack.cpp
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[f1]由systemserver進(jìn)程創(chuàng)建，在文件system_init.cpp里的函數(shù)system_init()調(diào)用MediaPlayerService::instantiate創(chuàng)建
[f2]返回3種player
PV_PLAYER:播放mp3
SONIVOX_PLAYER:播放midi
VORBIS_PLAYER:播放ogg,
簡單說來，軌跡如下：
Java端發(fā)起調(diào)用，MediaPlayer會轉(zhuǎn)至MediaPlayerService,然后會調(diào)用相應(yīng)的解碼工具解碼后創(chuàng)建AudioTrack，所有待輸出的AudioTrack在AudioFlinger::AudioMixer里合成，然后通過AudioHAL(AudioHardwareInterface的實際實現(xiàn)者)傳至實際的硬件來實現(xiàn)播放
