如何使用Xuggler獲取用於編碼的音頻

Question

我正在編寫一個記錄屏幕和音頻的應用程序。 雖然屏幕錄制效果很好，但我很難使用JDK庫獲取原始音頻。 這是代碼：

try {
            // Now, we're going to loop
            long startTime = System.nanoTime();

            System.out.println("Encoding Image.....");
            while (!Thread.currentThread().isInterrupted()) {
                // take the screen shot
                BufferedImage screen = robot.createScreenCapture(screenBounds);


                // convert to the right image type
                BufferedImage bgrScreen = convertToType(screen,
                        BufferedImage.TYPE_3BYTE_BGR);

                // encode the image
                writer.encodeVideo(0, bgrScreen, System.nanoTime()
                        - startTime, TimeUnit.NANOSECONDS);

                /* Need to get audio here and then encode using xuggler. Something like 

                    WaveData wd = new WaveData();

                    TargetDataLine line;
                    AudioInputStream aus = new AudioInputStream(line);

                    short[] samples = getSourceSamples();
                       writer.encodeAudio(0, samples); */


                if (timeCreation < 10) {
                    timeCreation = getGMTTime();
                }
                // sleep for framerate milliseconds
                try {
                    Thread.sleep((long) (1000 / FRAME_RATE.getDouble()));
                } catch (Exception ex) {
                    System.err.println("stopping....");
                    break;
                }

            }
            // Finally we tell the writer to close and write the trailer if
            // needed
        } finally {
            writer.close();
        }

這個頁面有一些偽代碼

while(haveMoreAudio())
 {
   short[] samples = getSourceSamples();
   writer.encodeAudio(0, samples);
 }

但是我應該為getSourceSamples()做些什么呢？

另外，一個額外的問題 - 這種方法可以從多個麥克風中進行選擇嗎？

另請參見： Xuggler編碼和多路復用

Answer 1

試試這個：

// Pick a format. Need 16 bits, the rest can be set to anything
// It is better to enumerate the formats that the system supports, because getLine() can error out with any particular format
AudioFormat audioFormat = new AudioFormat(44100.0F, 16, 2, true, false); 

// Get default TargetDataLine with that format
DataLine.Info dataLineInfo = new DataLine.Info( TargetDataLine.class, audioFormat );
TargetDataLine line = (TargetDataLine) AudioSystem.getLine(dataLineInfo);

// Open and start capturing audio    
line.open(audioFormat, line.getBufferSize());
line.start();

while (true) {
    // read as raw bytes
    byte[] audioBytes = new byte[ line.getBufferSize() / 2 ]; // best size?
    int numBytesRead = 0;
    numBytesRead =  line.read(audioBytes, 0, audioBytes.length);

    // convert to signed shorts representing samples
    int numSamplesRead = numBytesRead / 2;
    short[] audioSamples = new short[ numSamplesRead ];
    if (format.isBigEndian()) {
        for (int i = 0; i < numSamplesRead; i++) {
            audioSamples[i] = (short)((audioBytes[2*i] << 8) | audioBytes[2*i + 1]);
        }
    }
    else {
        for (int i = 0; i < numSamplesRead; i++) {
            audioSamples[i] = (short)((audioBytes[2*i + 1] << 8) | audioBytes[2*i]);
        }
    }

    // use audioSamples in Xuggler etc
}

要選擇麥克風，您可能必須這樣做：

Mixer.Info[] mixerInfo = AudioSystem.getMixerInfo();
// Look through and select a mixer here, different mixers should be different inputs
int selectedMixerIndex = 0;
Mixer mixer = AudioSystem.getMixer(mixerInfo[ selectedMixerIndex ]);
TargetDataLine line = (TargetDataLine) mixer.getLine(dataLineInfo);

我認為多個麥克風可能會在一個調音台中顯示為不同的源數據線。 在這種情況下，您必須打開它們並調用dataLine.getControl(FloatControl.Type.MASTER_GAIN).setValue( volume ); 打開和關閉它們。

請參閱： WaveData.java

來自TargetDataLine的聲波

如何在Java中設置SourceDataLine的卷