I am attempting to capture a video recording through an external camera, Logitec C922. Using java, I can make this possible through webcam api.
<dependency>
<groupId>com.github.sarxos</groupId>
<artifactId>webcam-capture</artifactId>
<version>0.3.10</version>
</dependency>
<dependency>
<groupId>xuggle</groupId>
<artifactId>xuggle-xuggler</artifactId>
<version>5.4</version>
</dependency>
However, for the life of me, I cannot make it record at 60FPS. The video randomly stutters when stored, and is not smooth at all.
I can connect to the camera, using the following details.
final List<Webcam> webcams = Webcam.getWebcams();
for (final Webcam cam : webcams) {
if (cam.getName().contains("C922")) {
System.out.println("### Logitec C922 cam found");
webcam = cam;
break;
}
}
I set the size of the cam to the following:
final Dimension[] nonStandardResolutions = new Dimension[] { WebcamResolution.HD720.getSize(), };
webcam.setCustomViewSizes(nonStandardResolutions);
webcam.setViewSize(WebcamResolution.HD720.getSize());
webcam.open(true);
And then I capture the images:
while (continueRecording) {
// capture the webcam image
final BufferedImage webcamImage = ConverterFactory.convertToType(webcam.getImage(),
BufferedImage.TYPE_3BYTE_BGR);
final Date timeOfCapture = new Date();
// convert the image and store
final IConverter converter = ConverterFactory.createConverter(webcamImage, IPixelFormat.Type.YUV420P);
final IVideoPicture frame = converter.toPicture(webcamImage,
(System.currentTimeMillis() - start) * 1000);
frame.setKeyFrame(false);
frame.setQuality(0);
writer.encodeVideo(0, frame);
}
My writer is defined as follows:
final Dimension size = WebcamResolution.HD720.getSize();
final IMediaWriter writer = ToolFactory.makeWriter(videoFile.getName());
writer.addVideoStream(0, 0, ICodec.ID.CODEC_ID_H264, size.width, size.height);
I am honestly not sure what in my code could be causing this. Given that I lower the resolution, I get no problems. ( 480p ) Could the issue be with the codes I am using?
As some of the comments mentioned, introducing queues does solve the problem. Here is the general logic to performs the needed steps. Note, I've setup my code for a lower resolution, as it allows me to capture 100FPS per sec. Adjust as needed.
Class to link the image/video capture and class to edit it :
public class WebcamRecorder {
final Dimension size = WebcamResolution.QVGA.getSize();
final Stopper stopper = new Stopper();
public void startRecording() throws Exception {
final Webcam webcam = Webcam.getDefault();
webcam.setViewSize(size);
webcam.open(true);
final BlockingQueue<CapturedFrame> queue = new LinkedBlockingQueue<CapturedFrame>();
final Thread recordingThread = new Thread(new RecordingThread(queue, webcam, stopper));
final Thread imageProcessingThread = new Thread(new ImageProcessingThread(queue, size));
recordingThread.start();
imageProcessingThread.start();
}
public void stopRecording() {
stopper.setStop(true);
}
}
RecordingThread :
public void run() {
try {
System.out.println("## capturing images began");
while (true) {
final BufferedImage webcamImage = ConverterFactory.convertToType(webcam.getImage(),
BufferedImage.TYPE_3BYTE_BGR);
final Date timeOfCapture = new Date();
queue.put(new CapturedFrame(webcamImage, timeOfCapture, false));
if (stopper.isStop()) {
System.out.println("### signal to stop capturing images received");
queue.put(new CapturedFrame(null, null, true));
break;
}
}
} catch (InterruptedException e) {
System.out.println("### threading issues during recording:: " + e.getMessage());
} finally {
System.out.println("## capturing images end");
if (webcam.isOpen()) {
webcam.close();
}
}
}
ImageProcessingThread:
public void run() {
writer.addVideoStream(0, 0, ICodec.ID.CODEC_ID_H264, size.width, size.height);
try {
int frameIdx = 0;
final long start = System.currentTimeMillis();
while (true) {
final CapturedFrame capturedFrame = queue.take();
if (capturedFrame.isEnd()) {
break;
}
final BufferedImage webcamImage = capturedFrame.getImage();
size.height);
// convert the image and store
final IConverter converter = ConverterFactory.createConverter(webcamImage, IPixelFormat.Type.YUV420P);
final long end = System.currentTimeMillis();
final IVideoPicture frame = converter.toPicture(webcamImage, (end - start) * 1000);
frame.setKeyFrame((frameIdx++ == 0));
frame.setQuality(0);
writer.encodeVideo(0, frame);
}
} catch (final InterruptedException e) {
System.out.println("### threading issues during image processing:: " + e.getMessage());
} finally {
if (writer != null) {
writer.close();
}
}
The way it works is pretty simple. The WebcamRecord class creates an instance of a queue that is shared between the video capture and the image processing. The RecordingThread sends bufferedImages to the queue ( in my case, it a pojo, called CapturedFrame ( which has a BufferedImage in it ) ). The ImageProcessingThread will listen and pull data from the queue. If it does not receive a signal that the writing should end, the loop never dies.