Gradually increase of the latency in Java Sound during executions

I'm writing a multi audio and video stream player in Java and I'm experiencing some latency/delays that mostly and gradually shows up if the application is left running for a while. Sometimes it is after just 2 mins or 20 mins or even after 1 hour later.

First I thought it was the SourceDataLine instantiation and I change it to a mixer from this: sdl = (SourceDataLine)AudioSystem.getLine(info); to sdl = (SourceDataLine)mixer.getLine(info);. However, it has the same results.

Initially it behaves as expected with a tiny delay of 250 ms approximately. However if the program is left running for a while then that delay is increased to several seconds.

I tested with different headsets. I tested with Java 8, 9, 10 and it consistently displays the same behaviour. I also experimented with drain() and flush() and so on but the only thing that gets rid of the delay is to close and recreate the SourceDataLine.

Finally I decided to implement an audio meter at the moment that I got an audio frame and I notice that what I heard is what audio meter shows. Therefore, the delay is not in the SourceDataLine but in the Frame frame = grabber.grab();

Then I check the ffplay source code and I found that they have a sync option that can be either one of these three options audio|video|ext. This option sets the audio-video sync type.

The ext type refers to AV_SYNC_EXTERNAL_CLOCK probably this configuration will help to synchronize the stream based on the RTSP clock parameter like in the ffplay implementation.

Probably this must be related to this other issue.