哦,你想找到音量?那么,并不是所有的硬件都支持它,但这里是你如何获得数据。
public static SourceDataLine getSourceDataLine(Line.Info lineInfo){
try{
return (SourceDataLine) AudioSystem.getLine(lineInfo);
}
catch(Exception ex){
ex.printStackTrace();
return null;
}
}
然后只需调用SourceDataLine.getLevel()即可获取该卷。我希望这有帮助。
注意:如果声音是从JVM之外发出的,或者不是通过JavaSound API发出的,则此方法不会检测到声音,因为JVM无法访问与SourceDataLine等效的操作系统。
更新:进一步研究后,大多数系统上都没有实现getLevel()。所以我手动实现基于该方法从论坛讨论:https://community.oracle.com/message/5391003
这里是类:
public class Main {
public static void main(String[] args){
MicrophoneAnalyzer mic = new MicrophoneAnalyzer(FLACFileWriter.FLAC);
System.out.println("HELLO");
mic.open();
while(true){
byte[] buffer = new byte[mic.getTargetDataLine().getFormat().getFrameSize()];
mic.getTargetDataLine().read(buffer, 0, buffer.length);
try{
System.out.println(getLevel(mic.getAudioFormat(), buffer));
}
catch(Exception e){
System.out.println("ERROR");
e.printStackTrace();
}
}
}
public static double getLevel(AudioFormat af, byte[] chunk) throws IOException{
PCMSigned8Bit converter = new PCMSigned8Bit(af);
if(chunk.length != converter.getRequiredChunkByteSize())
return -1;
AudioInputStream ais = converter.convert(chunk);
ais.read(chunk, 0, chunk.length);
long lSum = 0;
for(int i=0; i<chunk.length; i++)
lSum = lSum + chunk[i];
double dAvg = lSum/chunk.length;
double sumMeanSquare = 0d;
for(int j=0; j<chunk.length; j++)
sumMeanSquare = sumMeanSquare + Math.pow(chunk[j] - dAvg, 2d);
double averageMeanSquare = sumMeanSquare/chunk.length;
return (Math.pow(averageMeanSquare,0.5d));
}
}
我使用的方法仅适用于8bitPCM所以我们的编码转换,使用这两个来类。这是一般的抽象转换器类。
import java.io.ByteArrayInputStream;
import java.io.IOException;
import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;
abstract class AbstractSignedLevelConverter
{
private AudioFormat srcf;
public AbstractSignedLevelConverter(AudioFormat sourceFormat)
{
srcf = sourceFormat;
}
protected AudioInputStream convert(byte[] chunk)
{
AudioInputStream ais = null;
if(AudioSystem.isConversionSupported( AudioFormat.Encoding.PCM_SIGNED,
srcf))
{
if(srcf.getEncoding() != AudioFormat.Encoding.PCM_SIGNED)
ais = AudioSystem.getAudioInputStream(
AudioFormat.Encoding.PCM_SIGNED,
new AudioInputStream(new ByteArrayInputStream(chunk),
srcf,
chunk.length * srcf.getFrameSize()));
else
ais = new AudioInputStream(new ByteArrayInputStream(chunk),
srcf,
chunk.length * srcf.getFrameSize());
}
return ais;
}
abstract public double convertToLevel(byte[] chunk) throws IOException;
public int getRequiredChunkByteSize()
{
return srcf.getFrameSize();
}
}
这里是一个8BitPCM
import java.io.IOException;
import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioInputStream;
public class PCMSigned8Bit extends AbstractSignedLevelConverter
{
PCMSigned8Bit(AudioFormat sourceFormat)
{
super(sourceFormat);
}
public double convertToLevel(byte[] chunk) throws IOException
{
if(chunk.length != getRequiredChunkByteSize())
return -1;
AudioInputStream ais = convert(chunk);
ais.read(chunk, 0, chunk.length);
return (double)chunk[0];
}
}
这是TargetDataLine的可能不是你使用的情况下工作,但你可以建立一个围绕的SourceDataLine的包装,并用它来正确地实现这些方法。希望这有助于。
考虑添加一个Audio或Javasound标记来提醒用户这个特别的兴趣! –