2011.08.15（2）——— android audioManager解决MediaPlayer AudioTrack 调节音量问题

2011.08.15（2）——— android audioManager解决MediaPlayer AudioTrack 调节音量问题

参考：http://www.pocketdigi.com/20110717/398.html

在听筒模式下

am.setSpeakerphoneOn(false);setVolumeControlStream(AudioManager.STREAM_VOICE_CALL);am.setMode(AudioManager.MODE_IN_CALL);

我用Mediaplayer AudioTrack调节音量总是失败

at.setStereoVolume(vol, vol);player.setVolume(vol，vol);

后来决定用AudioManager来调节音量

AudioManager可以修改系统Android系统的音量
下面介绍几个AudioManager的几个音量调整方面的方法.
首先是得到AudioManager实例:

AudioManager am=(AudioManager)getSystemService(Context.AUDIO_SERVICE);

调整音量方法有两种,一种是渐进式,即像手动按音量键一样,一步一步增加或减少,另一种是直接设置音量值.
1、渐进式

public void adjustStreamVolume (int streamType, int direction, int flags)am.adjustStreamVolume (AudioManager.STREAM_MUSIC, AudioManager.ADJUST_RAISE, AudioManager.FLAG_SHOW_UI);

解释一下三个参数

第一个streamType是需要调整音量的类型,这里设的是媒体音量,可以是:STREAM_ALARM 警报STREAM_MUSIC 音乐回放即媒体音量STREAM_NOTIFICATION 窗口顶部状态栏Notification,STREAM_RING 铃声STREAM_SYSTEM 系统STREAM_VOICE_CALL 通话STREAM_DTMF 双音多频,不是很明白什么东西第二个direction,是调整的方向,增加或减少,可以是:ADJUST_LOWER 降低音量ADJUST_RAISE 升高音量ADJUST_SAME 保持不变,这个主要用于向用户展示当前的音量第三个flags是一些附加参数,只介绍两个常用的FLAG_PLAY_SOUND 调整音量时播放声音FLAG_SHOW_UI 调整时显示音量条,就是按音量键出现的那个0 表示什么也没有

2、直接设置音量值的方法:

public void setStreamVolume (int streamType, int index, int flags)am.setStreamVolume(AudioManager.STREAM_MUSIC, am.getStreamMaxVolume(AudioManager.STREAM_MUSIC), AudioManager.FLAG_PLAY_SOUND);am.getStreamMaxVolume(AudioManager.STREAM_VOICE_CALL);//得到听筒模式的最大值am.getStreamVolume(AudioManager.STREAM_VOICE_CALL);//得到听筒模式的当前值

第一个和第三个参数与上面的相同
第二个参数是一个音量的int值,getStreamMaxVolume(int streamType)得到的是该类型音量的最大值,可以根据这个值计算你需要的音量,我这里直接调到最大.

最后我的代码：

package com.lp;import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.IOException;import java.io.InputStream;import android.app.Activity;import android.content.Context;import android.media.AudioFormat;import android.media.AudioManager;import android.media.AudioTrack;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.SeekBar;/** * AudioTrack 播放音频 如wav格式 * 并允许调节音量 * @author Administrator * */public class MainActivity5 extends Activity {private Button play;private Button stop;private SeekBar soundValue;private AudioTrack at;private AudioManager am;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main_sk);        am = (AudioManager)getSystemService(Context.AUDIO_SERVICE);        play = (Button)findViewById(R.id.main_sk_play);        stop = (Button)findViewById(R.id.main_sk_stop);        soundValue = (SeekBar)findViewById(R.id.skbVolume);        setVolumeControlStream(AudioManager.STREAM_VOICE_CALL);        play.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {if(am.isSpeakerphoneOn()){am.setSpeakerphoneOn(false);}//setVolumeControlStream(AudioManager.STREAM_VOICE_CALL);am.setMode(AudioManager.MODE_IN_CALL);System.out.println(am.getStreamMaxVolume(AudioManager.STREAM_VOICE_CALL));System.out.println("&&&&&&&&&&&&&");System.out.println(am.getStreamVolume(AudioManager.STREAM_VOICE_CALL));//am.setStreamVolume(streamType, index, flags)int bufferSizeInBytes = AudioTrack.getMinBufferSize(44100, AudioFormat.CHANNEL_OUT_MONO, AudioFormat.ENCODING_PCM_16BIT);if(at==null){at = new AudioTrack(AudioManager.STREAM_VOICE_CALL, 44100, AudioFormat.CHANNEL_OUT_MONO, AudioFormat.ENCODING_PCM_16BIT, bufferSizeInBytes, AudioTrack.MODE_STREAM);System.out.println("22222");//at.setStereoVolume(100f, 100f);at.setStereoVolume(0.7f, 0.7f);//设置当前音量大小new AudioTrackThread().start();}else{if(at.getPlayState()==AudioTrack.PLAYSTATE_PLAYING){System.out.println("111111111");}else{System.out.println("33333");at = new AudioTrack(AudioManager.STREAM_VOICE_CALL, 44100, AudioFormat.CHANNEL_OUT_MONO, AudioFormat.ENCODING_PCM_16BIT, bufferSizeInBytes, AudioTrack.MODE_STREAM);new AudioTrackThread().start();}}}        });                stop.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {if(at.getPlayState()==AudioTrack.PLAYSTATE_PLAYING){try{at.stop();}catch (IllegalStateException e){e.printStackTrace();}at.release();am.setMode(AudioManager.MODE_NORMAL);}}   });        //        soundValue.setMax(100);//音量调节的极限//        soundValue.setProgress(70);//设置seekbar的位置值        soundValue.setMax(am.getStreamMaxVolume(AudioManager.STREAM_VOICE_CALL));        soundValue.setProgress(am.getStreamVolume(AudioManager.STREAM_VOICE_CALL));soundValue.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {@Overridepublic void onStopTrackingTouch(SeekBar seekBar) {//float vol=(float)(seekBar.getProgress())/(float)(seekBar.getMax());//System.out.println(vol);//at.setStereoVolume(vol, vol);//设置音量am.setStreamVolume(AudioManager.STREAM_VOICE_CALL, seekBar.getProgress(), AudioManager.FLAG_PLAY_SOUND);}@Overridepublic void onStartTrackingTouch(SeekBar seekBar) {// TODO Auto-generated method stub}@Overridepublic void onProgressChanged(SeekBar seekBar, int progress,boolean fromUser) {// TODO Auto-generated method stub}});    }        class AudioTrackThread extends Thread{  @Overridepublic void run() {byte[] out_bytes = new byte[44100];InputStream is = getResources().openRawResource(R.raw.start);    int length ;try{at.play();}catch (IllegalStateException e){e.printStackTrace();}try {while((length = is.read(out_bytes))!=-1){//System.out.println(length);at.write(out_bytes, 0, length);}} catch (IOException e) {e.printStackTrace();}if(at.getPlayState()==AudioTrack.PLAYSTATE_PLAYING){try{at.stop();}catch (IllegalStateException e){e.printStackTrace();}at.release();am.setMode(AudioManager.MODE_NORMAL);}}        }}

当然权限

<uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS" />    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> <uses-permission android:name="android.permission.RECORD_AUDIO" />

更多相关文章

随机推荐