Android4.4

输入输出设备

输入输出设备，定义在frameworks/base/media/java/android/media/AudioSystem.java和system/core/include/system/audio.h

        // output devices
        DEVICE_OUT_EARPIECE = 0x1,    //听筒
        DEVICE_OUT_SPEAKER = 0x2,    //扬声器
        DEVICE_OUT_WIRED_HEADSET = 0x4,     //带话筒的耳机
        DEVICE_OUT_WIRED_HEADPHONE = 0x8, //不带话筒的耳机
        DEVICE_OUT_BLUETOOTH_SCO = 0x10,  //蓝牙.面向连接（SCO）方式：主要用于话音传输
        DEVICE_OUT_BLUETOOTH_SCO_HEADSET = 0x20,    //蓝牙耳机,带话筒
        DEVICE_OUT_BLUETOOTH_SCO_CARKIT = 0x40,  //蓝牙车载设备
        DEVICE_OUT_BLUETOOTH_A2DP = 0x80,    //蓝牙立体声
        DEVICE_OUT_BLUETOOTH_A2DP_HEADPHONES = 0x100,  //蓝牙立体声音耳机
        DEVICE_OUT_BLUETOOTH_A2DP_SPEAKER = 0x200,
        DEVICE_OUT_AUX_DIGITAL = 0x400,
        DEVICE_OUT_ANLG_DOCK_HEADSET = 0x800,
        DEVICE_OUT_DGTL_DOCK_HEADSET = 0x1000,
        DEVICE_OUT_FM_HEADPHONE = 0x800,
        DEVICE_OUT_FM_SPEAKER = 0x1000,
        DEVICE_OUT_SPEAKER_SSPA2 = 0x2000,
        DEVICE_OUT_HDMI = 0x4000,
        DEVICE_OUT_FM_TRANSMITTER = 0x8000,
        DEVICE_OUT_DEFAULT = 0x8000,
 
        // input devices
        DEVICE_IN_COMMUNICATION = 0x10000,
        DEVICE_IN_AMBIENT = 0x20000,
        DEVICE_IN_BUILTIN_MIC = 0x40000,
        DEVICE_IN_BLUETOOTH_SCO_HEADSET = 0x80000,
        DEVICE_IN_WIRED_HEADSET = 0x100000,
        DEVICE_IN_AUX_DIGITAL = 0x200000,
        DEVICE_IN_VOICE_CALL = 0x400000,
        DEVICE_IN_BACK_MIC = 0x800000,
        DEVICE_IN_VT_MIC  = 0x1000000,
        DEVICE_IN_FMRADIO  = 0x2000000,
        DEVICE_IN_DEFAULT = 0x80000000,