tl;dr 对于 future 的读者,使用 Java 或 C# 录制实时音频不可能(目前)。使用 C++,因为它提供了大量的音频 API。
我的目标是获取当前在 Windows 机器上播放的声音,并像图形音频可视化工具一样分析声音(获取音量属性和 Hz(低音和高音))。当我说当前声音时,我的意思是如果要播放 Youtube 视频或 Spotify 歌曲,并且该程序将读取该音频输出。我无意播放声音,而是实时捕捉并可视化。
在尝试这样做时,我阅读了如何 build an audio waveform display它涉及如何将音频文件转换为字节数组(一行)。这没有帮助,因为它不会得到当前的声音。我还阅读了如何 capture audio还有,和this java accessing sound tutorial ,这些都没有回答我的问题,因为它们都需要加载歌曲文件。
我只是完全不明白这一点。我完全一无所知,如有任何帮助,我们将不胜感激。
编辑:我环顾四周,second answer from this source让我得出这样的结论:我可以找到所有的音频设备,看看哪个在发出声音。我不知道之后该怎么办。
编辑 2(再次编辑):通过试验和环顾四周,我在下面编写了这段代码。我认为这让我朝着我想要的方向前进,但我不知道如何完成它。
Mixer.Info[] mixers = AudioSystem.getMixerInfo();
for (Mixer.Info mixerInfo : mixers) {
Mixer mixer = AudioSystem.getMixer(mixerInfo);
try {
mixer.open();
Line.Info[] lines = mixer.getTargetLineInfo();
for (Line.Info linfo : lines) {
Line line = AudioSystem.getLine(linfo);
//here I'm opening the line, but I don't know how to grab data
line.open();
}
} catch (LineUnavailableException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
我使用了这个来源:Checking The Level of Audio-Playback in a mixers line ,但我不想检查所有正在播放音量的线路,我只需要用户默认的混音器,获取该线路,并能够分析数据。
编辑 3:我试过:
//creating a format for getting sound
float sampleRate = 8000;
int sampleSizeInBits = 16;
int channels = 2;
boolean signed = true;
boolean bigEndian = true;
AudioFormat format = new AudioFormat(sampleRate, sampleSizeInBits, channels,
signed, bigEndian);
//creating a line based off of the format
DataLine.Info info = new DataLine.Info( TargetDataLine.class, format);
TargetDataLine line = (TargetDataLine) AudioSystem.getLine(info);
//opening and starting that line
line.open(format);
line.start();
while (conditionIsTrue){
//here, I don't know what to put as the parameters.
//Had I known, I don't know how I would get to analyze the data
line.read();
}
我认为我使用上面的代码是正确的,但我不知道如何提取声音并找到 bpm、低音、高音等。
编辑 4:这是一篇有趣的读物:Real-time low latency audio processing in Java .这并没有涉及什么类以及如何实际实现它,但它提供了一些见解。
编辑 5:@AndrewThompson 使用基于您的链接的这段代码,我能够迭代可用的源和目标行。
Mixer.Info[] mixers = AudioSystem.getMixerInfo();
for (Mixer.Info mixerInfo : mixers) {
Mixer mixer = AudioSystem.getMixer(mixerInfo);
try {
mixer.open();
Line.Info[] sourceLines = mixer.getSourceLineInfo();
Line.Info[] targetLine = mixer.getTargetLineInfo();
for (Line.Info sourceLinfo : sourceLines) {
System.out.println(sourceLinfo );
}
for (Line.Info targetLinefo : targetLine) {
System.out.println(targetLinefo);
}
} catch (LineUnavailableException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
输出看起来像这样:
interface SourceDataLine supporting 8 audio formats, and buffers of at least 32 bytes
interface Clip supporting 8 audio formats, and buffers of at least 32 bytes
interface SourceDataLine supporting 8 audio formats, and buffers of at least 32 bytes
interface Clip supporting 8 audio formats, and buffers of at least 32 bytes
interface SourceDataLine supporting 8 audio formats, and buffers of at least 32 bytes
interface Clip supporting 8 audio formats, and buffers of at least 32 bytes
HEADPHONE target port
SPEAKER target port
然后我创建了一个方法来获取所有线路的声级,如下所示:
private static void getVolumeOfAllLines() {
Mixer.Info[] mixers = AudioSystem.getMixerInfo();
for (Mixer.Info mixerInfo : mixers) {
Mixer mixer = AudioSystem.getMixer(mixerInfo);
try {
mixer.open();
Line.Info[] lines = mixer.getSourceLineInfo();
for (Line.Info linfo : lines) {
DataLine line = (DataLine)AudioSystem.getLine(linfo);
if(line != null)
System.out.println(line.getLevel());
}
} catch (LineUnavailableException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
-in 尝试找到当前播放声音的行,表示音量更高。这将返回:
-1.0
-1.0
-1.0
-1.0
-1.0
-1.0
没有进展。
新代码:
private static void debug(){
Mixer.Info[] mixers = AudioSystem.getMixerInfo();
for (Mixer.Info mixerInfo : mixers) {
Mixer mixer = AudioSystem.getMixer(mixerInfo);
try {
mixer.open();
Line.Info[] lines = mixer.getTargetLineInfo();
AudioFormat format = new AudioFormat(
AudioFormat.Encoding.PCM_SIGNED,
44100,
16, 2, 4,
44100, false);
AudioFormat[] tdl = AudioSystem.getTargetFormats(AudioFormat.Encoding.PCM_SIGNED, format);
for (Line.Info linfo : lines) {
//Line line = AudioSystem.getLine(linfo);
TargetDataLine line = null;
DataLine.Info info = new DataLine.Info(TargetDataLine.class,
format); // format is an AudioFormat object
if (!AudioSystem.isLineSupported(info))
{
System.out.println("line not supported:" + line );
}
try
{
line = (TargetDataLine) AudioSystem.getLine(info); //error
line.open(format);
System.out.println("line opened:" + line);
line.start();
byte[] buffer = new byte[1024];
int ii = 0;
int numBytesRead = 0;
while (ii++ < 100) {
// Read the next chunk of data from the TargetDataLine.
numBytesRead = line.read(buffer, 0, buffer.length);
System.out.println("\nnumBytesRead:" + numBytesRead);
if (numBytesRead == 0) continue;
// following is a quickie test to see if content is only 0 vals
// present in the data that was read.
for (int i = 0; i < 16; i++)
{
if (buffer[i] != 0)
System.out.print(".");
else
System.out.print("0");
}
}
} catch (LineUnavailableException ex) {
ex.printStackTrace();
//...
}
}
} catch (LineUnavailableException e) {
e.printStackTrace();
}
}
}
最佳答案
Java 教程中有一个很好的示例可以帮助您从一行中提取 PCM 数据。在标题为 Using Files and Format Converters 的教程中在“读取声音文件”部分标题下有一个代码示例。相关部分是“片段”示例,并用代码标记:
// Here, do something useful with the audio data that's
// now in the audioBytes array...
至此,您已经可以访问该行的各个字节,并可以根据声音文件的格式将它们组装成PCM。还有其他几个 stackoverflow 问题,它们处理从字节到 PCM 的具体情况。
正在添加一些代码以响应评论。
由于无法转换为 TargetDataLine,从教程中提取的以下内容允许我转换为 TargetDataLine。
AudioFormat format = new AudioFormat(
AudioFormat.Encoding.PCM_SIGNED,
44100,
16, 2, 4,
44100, false);
TargetDataLine line = null;
DataLine.Info info = new DataLine.Info(TargetDataLine.class,
format); // format is an AudioFormat object
if (!AudioSystem.isLineSupported(info))
{
System.out.println("line not supported:" + line );
}
try
{
line = (TargetDataLine) AudioSystem.getLine(info);
line.open(format);
System.out.println("line opened:" + line);
line.start();
byte[] buffer = new byte[1024];
int ii = 0;
int numBytesRead = 0;
while (ii++ < 100) {
// Read the next chunk of data from the TargetDataLine.
numBytesRead = line.read(buffer, 0, buffer.length);
System.out.println("\nnumBytesRead:" + numBytesRead);
if (numBytesRead == 0) continue;
// following is a quickie test to see if content is only 0 vals
// present in the data that was read.
for (int i = 0; i < 16; i++)
{
if (buffer[i] != 0)
System.out.print(".");
else
System.out.print("0");
}
}
} catch (LineUnavailableException ex) {
ex.printStackTrace();
//...
}
}
但我只是使用 CD 质量格式方案抓取一条线,我没有试图找出哪条线有来自正在播放的 YouTube channel 的声音。
OP 和我去聊天并继续破解这个问题,但无法找到解决方案。似乎许多其他人也看到了这一点并放弃了。我希望赏金很有吸引力——这是一个有趣的问题。
关于Java 音频可视化工具 - 如何捕获实时声音输出到扬声器?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/38842255/