Java 音频分贝声压级的计算
我正在用java编写一个简单的db SPL表,试图理解一些关于如何计算它的理论,现在得到了这段代码Java 音频分贝声压级的计算,java,audio,Java,Audio,我正在用java编写一个简单的db SPL表,试图理解一些关于如何计算它的理论,现在得到了这段代码 import java.io.IOException; import javax.sound.sampled.AudioFormat; import javax.sound.sampled.AudioInputStream; import javax.sound.sampled.AudioSystem; import javax.sound.sampled.DataLine; import ja
import java.io.IOException;
import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.DataLine;
import javax.sound.sampled.LineUnavailableException;
import javax.sound.sampled.TargetDataLine;
public class Sound {
public static void main(String[] args) throws LineUnavailableException, InterruptedException, IOException {
AudioFormat audioFormat = new AudioFormat(44100f, 16, 1, true, true);
DataLine.Info info = new DataLine.Info(TargetDataLine.class, audioFormat);
if (!AudioSystem.isLineSupported(info)) {
System.err.println("Line is not supperted");
return;
}
TargetDataLine targetDataLine = AudioSystem.getTargetDataLine(audioFormat);
int bufferSize = targetDataLine.getBufferSize() / 5;
targetDataLine.open(audioFormat, bufferSize);
targetDataLine.start();
AudioInputStream audioInputStream = new AudioInputStream(targetDataLine);
byte[] buffer = new byte[bufferSize];
for (int blen; (blen = audioInputStream.read(buffer, 0, buffer.length)) > -1;) {
float[] samples = new float[buffer.length / 2];
for (int i = 0, s = 0; i < blen;) {
samples[s++] = (buffer[i++] << 8 | buffer[i++] & 0xFF) / 32768f;
}
double rms = 0;
for(float sample : samples) {
rms += Math.pow(sample,2);
}
rms = (double) Math.sqrt(rms/samples.length);
double db = 20.0 * Math.log10(rms);
System.out.println("rms:" + rms + " => db: " + db);
}
audioInputStream.close();
targetDataLine.stop();
targetDataLine.close();
}
}
在麦克风的相同位置使用一个外部应用程序(ios上没有分贝表),我可以得到大约6-10分贝的正的更有意义的值
我如何正确计算该值,使其至少接近或等于app medition的值?我做错了什么?试试:
float db = 20.0 * Math.log10(rms);
PCM(音频)数据以32位Float
格式处理,而不是以64位Double
格式处理。尝试:
float db = 20.0 * Math.log10(rms);
PCM(音频)数据以32位Float
而不是64位Double
类型处理