Is is single-threaded only? about gst1-java-core HOT 4 CLOSED

The library is a wrapper for GStreamer - it uses whatever threading is set up for the pipeline by the underlying native library, which is ultimately up to what you set up. While that might be single-threaded, it should not be running on the thread you call pipeline.play() on. However, some of the initialization of the pipeline might happen on the thread you call pipeline.play() on. Does that never return?

Please share some more of your code setup - it's impossible to guess what's happening here. Also, if your pipeline initialization is taking more time than you want, you can use Gst.invokeLater() or Gst.getScheduledExecutorService().

from gst1-java-core.

pipeline.play() always returns pretty much instantly. Though a glance at the task manager on KDE/Linux tells me that the whole Java process including GStreamer uses only one the sixteen physical threads (8 cores with SMT). Now what I did then was calling pipeline.play() in a new thread which made Java use two physical threads. What improved it further, though apparently not using more threads, was adding "used-cpu" option to the vp8enc pad.

According to the GStreamer documentation, GStreamer is supposedly "inherently multithreaded" and using queues supposedly forces more threads. So somewhere in between Java and GStreamer is something wrong, it seems, or I am doing it wrong, or the docs are "PR talk". Here's essentially my pipeline: http://lyrion.ch/share/pipeline.png (codecs have changed, and I added number of threads (without effect) and "used-cpu" to the video encoder)

from gst1-java-core.

I have to say the most likely answer is you're doing something wrong! There may be issues in the bindings but it's unlikely they would have any effect on threading. You can build a similar pipeline on the CLI with gst-launch and see if that behaves any differently.

I'm sceptical about some aspects of that pipeline - whether the layout is actually parallelizable and whether those queues are required.

I would try replicating some of the simpler multi-threaded examples from upstream and see how you get on. I would also follow up on the GStreamer mailing lists and check that pipeline.

I haven't used KDE for a long time, so not sure how useful the task manager is for actually seeing exactly what's going on here.

from gst1-java-core.

Not heard further on this so closing. Thanks.

from gst1-java-core.