grabbing frames only in each second

[xseser]

private void initialiseFrameGrabber() {
log.info("Starting new stream");
this.frameGrabber = new FFmpegFrameGrabber(RTSP_URL);
this.frameGrabber.setFrameRate(1);
try {
this.frameGrabber.start();
} catch (FrameGrabber.Exception e) {
log.error("error during starting frame grabber {}", e.getMessage());
}
}

private void grabAndProcessFrame() {
    while (true) {
        try {
            Frame frame = frameGrabber.grab();
            boolean t = frame.keyFrame;
            log.info("t: {}", t);
            if (frame != null) {
                log.info("Getting new frame with time: {}", now());
                byte[] image = imageConverter.convertFrameToByteArray(frame);
                executor.execute(() -> recognitionService.recognizePlate(image));
            }

// frameGrabber.waitForTimestamp()
// Thread.sleep(1000);
} catch (FrameGrabber.Exception e) {
log.error("Exception during getting new frame! {}", e.getMessage());
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
}
}

I want actually to grab frame only on each second. This is not valid code because it grabes frames which are in stream queue. Do you have some code or any solution how to handle getting frames only at each second, or to delay them somehow?

[saudet]

You might be able to use setTimestamp() for this.

[xseser]

@saudet Can you show me example of this usage?

[xseser]

@saudet I also after about an hour of usage have 100% usage of processor.
How can I resolve issue?
My goal is to keep server running with this library downloading images each second.

[saudet]

I'd start by calling something like grabber.setTimestamp(grabber.getTimestamp() + 1000000) before each call to grab().

[xseser]

Currently I am using function like:
private void grabAndProcessFrame() {
while (true) {
try {
frameGrabber.delayedGrab(1000000);
Frame frame = frameGrabber.getDelayedFrame();
if (frame != null) {
log.info("Getting new frame with time: {}", new Date(frame.timestamp));
byte[] image = imageConverter.convertFrameToByteArray(frame);
executor.execute(() -> recognitionService.recognizePlate(image));
}
} catch (InterruptedException | ExecutionException e) {
log.error("Error while getting delayed frame {}", e.getMessage());
}
}
}
It's working fine to me, but I have problems with 100% usage of memory, after about hour :/

[saudet]

That should work too. You'll need to make sure you don't keep copies of the images in memory to avoid running out of it

[xseser]

In my code I only grab a frame and I just put it in another service. Even thou in my component when I'm only grabbing frames I run out of memory.

[saudet]

Do you run out of memory only with delayedGrab()? Or does it happen with normal grab() as well?

[saudet]

In any case, if you could provide a small standalone code snippet to reproduce the issue, I would be able to look into this