Starting VLC in Java with Runtime.exec() consumes a lot CPU!

[dhirwinjr]

All,

I have a Java application that I've developed to view/control video. I use VLC as the video software decoder and so far it's worked really well (I've looked at jVLC but that just wasn't going to work for this application). One issue, however, is that VLC consumes a lot of CPU when I start it using Java and Runtime.exec(). In particular, I have something similar in my current setup (this is from memory so it may not be 100% correct):

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System.getRuntime().exec("C:\Documents and Settings\d.irwin\VideoLAN-0.8.6d\VLC\vlc.exe -I telnet --telnet-host 192.168.0.72:4212 -I rc --rc-host 192.168.0.72:4214 --video-title /"Video Title [192.168.0.72:4212]/"");

In my actual design I pass the resulting Process object to a custom process handler that creates a couple of threads to read in the output streams coming from VLC (per some other suggestions in this forum and others). When VLC is started on my laptop it consumes just about 50% of the CPU and it's not even decoding any video. If, however, I launch VLC from the Windows command line using the exact same command as above VLC consumes maybe 1%-2%.

Note: VLC consumed 50% CPU both before and after I created the process handler/stream reader so that didn't really make any difference.

Any suggestions? This is really causing a problem on some slightly older computers that really chug along when they actually start to decode live video.

Thanks,
Dave

Java 1.5+ on Windows XP with VLC 0.8.6d+

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A little more research done. I found that the following works fine in that it doesn't cause any high CPU consumption:

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private final String vlcPath = "C:\\Documents and Settings\\d.irwin\\VideoLAN-0.8.6d\\VLC\\vlc.exe"; private final String[] args = { vlcPath, "-I", "telnet", "--telnet-host", "192.168.0.72:4212" }; ... try { Runtime.getRuntime().exec(args); } catch (IOException ioe) { System.err.println("IO exception: " + ioe.getMessage()); }

However, if I add the VLC option to enable the remote control interface via the command line all of a sudden the CPU consumption hits 50%.

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private final String vlcPath = "C:\\Documents and Settings\\d.irwin\\VideoLAN-0.8.6d\\VLC\\vlc.exe"; private final String[] args = { vlcPath, "-I", "telnet", "--telnet-host", "192.168.0.72:4212", "-I", "rc", "--rc-host", "192.168.0.72:4214" }; ... try { Runtime.getRuntime().exec(args); } catch (IOException ioe) { System.err.println("IO exception: " + ioe.getMessage()); }

Weird.

[dhirwinjr]

It turns out that if you use the "--rc-quite" command line option this fixes the high CPU usage problem when starting VLC using Java. In turn, however, I found that if you have opened the input streams that you can use to view the output from VLC when you try to close the streams (i.e. when you try to close VLC via Java) Java just hangs. If I don't use these input streams then VLC will exit normally via Java.

Dave

[agussi]

hi dhirwinjr,

thanks for your post
I am also using a runtime.exec command to launch and use vlc.
what do you mean by :

It turns out that if you use the "--rc-quite" command line option this fixes the high CPU usage problem when starting VLC using Java.

Can you give me your command line, please?

thx

[dhirwinjr]

hi dhirwinjr,

thanks for your post
I am also using a runtime.exec command to launch and use vlc.
what do you mean by :

It turns out that if you use the "--rc-quite" command line option this fixes the high CPU usage problem when starting VLC using Java.

Can you give me your command line, please?

thx

Just add the "--rc-quite" option to the command line. For example, here's the command line that I now use:

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System.getRuntime().exec("C:\Documents and Settings\d.irwin\VideoLAN-0.8.6d\VLC\vlc.exe -I telnet --telnet-host 192.168.0.72:4212 -I rc --rc-host 192.168.0.72:4214 --rc-quite --video-title /"Video Title [192.168.0.72:4212]/"");

In some initial testing on the particular machine I was using (a Pentium IV with 1 GB of RAM with a medium range ATI Radeon graphics card) it help reduce CPU consumption by 25-35%.

Dave