android 默認系統音量定義

OS:MTK 8.1

1.音量最大值

• frameworks/base/services/core/java/come/android/server/audio/AudioService.java

 /** @hide Maximum volume index values for audio streams */
    private int[] MAX_STREAM_VOLUME = new int[] {
        7,  // STREAM_VOICE_CALL
        15, // STREAM_SYSTEM
        15, // STREAM_RING
        15, // STREAM_MUSIC
        15, // STREAM_ALARM
        15, // STREAM_NOTIFICATION
        15, // STREAM_BLUETOOTH_SCO
        15, // STREAM_SYSTEM_ENFORCED
        15, // STREAM_DTMF
        15, // STREAM_TTS
        
    };

2.音量最小值

/** @hide Minimum volume index values for audio streams */
    private int[] MIN_STREAM_VOLUME = new int[] {
        1,  // STREAM_VOICE_CALL
        0, // STREAM_SYSTEM
        0, // STREAM_RING
        0, // STREAM_MUSIC
        0, // STREAM_ALARM
        0, // STREAM_NOTIFICATION
        0, // STREAM_BLUETOOTH_SCO
        0, // STREAM_SYSTEM_ENFORCED
        0, // STREAM_DTMF
        0, // STREAM_TTS
        
    };

3.音量默認值

• frameworks/base/media/java/android/media/AudioSystem.java

/** default volume index values for audio streams */
	 private int[] DEFAULT_STREAM_VOLUME = new int[] {
        4,  // STREAM_VOICE_CALL
        7, // STREAM_SYSTEM
        5, // STREAM_RING
        11, // STREAM_MUSIC
        6, // STREAM_ALARM
        5, // STREAM_NOTIFICATION
        7, // STREAM_BLUETOOTH_SCO
        7, // STREAM_SYSTEM_ENFORCED
        11, // STREAM_DTMF
        11, // STREAM_TTS
        
    };