Recently I built myself a media center of old HP/Compaq computer and MythBuntu. It all worked as a top and I spent weeks learning about great features it has.
This week I was hoping to put some finishing touches on it. The last missing piece arrived – so-called “Vista Rock Remote”.
According to MythBunty HOWTO, this MCE-compatible remote should work out of box, despite some reviews saying it would only work with Vista. Don’t know if it works with Vista though, but it worked in MythBunty just fine. I only had to enable it in Mythbuntu control center. And restart MythTV frontend, of course.
Funnily enough, I noticed the big problem straight away. Every time I put recorded TV show on and tried to use volume up/down buttons on remote, the picture was getting sluggish and jumpy for noticeable time. Actually, it felt so weird I even thought that I might be only one who had that problem. I was not right – there were plenty of similar reports on Internet. And there was a workaround proposed also.
The root cause of the problem is that MythTV pokes X screensaver every time button on remote is pressed. It does not have to do so when you use keyboard, but must do it when you use remote as screensaver has no idea about it. MythTV kicks the screensaver by invoking “gnome-screensaver-command” with parameter –poke, and there are reports it does it twice every time you press the button. It isn’t itself a problem, the problem is that when this command is called often (and it exactly what happens when you try to put volume up or down) XOrg CPU usage jumps to 100%, which causes that unwanted “special effect” in your video.
This bug, however, has already been reported (here and here) and the fix will probably be included in next MythTV release. For now, the only workaround was to disable screensaver and create a symbolic link to /bin/true with name gnome-screensaver-command somwehre in one of PATH’s directories that comes in front of where the original program resides. Say, if your PATH looks like
/usr/sbin;/usr/bin;/usr/local/bin
and gnome-screensaver-command is in /usr/local/bin, you can stop it from being called by creating link to /bin/true in either/usr/sbin or /usr/bin:
ln -s /bin/true /usr/bin/gnome-screensaver-command
But it would only work if you decide to disable the screensaver. You can try not to, but once display goes to sleep, you won’t be able to wake it up by using remote. So I decided to invent something more sophisticated.
Of course, I could download sources, fix the bug and build MythTV myself, but I decided to leave it to mythbuntu team. Instead, I written small program that simply does not allow screensaver to be poked more often than once in a minute, which fixed the problem.
The good news: you can download it from this site: Mythtv screensaver proxy
The bad news: you must build it yourself. So, installing build-essentials first would be a good idea.
Download cpp file above somewhere in your home directory and then follow simple steps described in file header:
/*
* Usage:
* 1. execute "which gnome-screensaver-comand"
* If output is different from what you find below in
* DEF_PROGRAM, modify this macro accordingly.
*
* 2. build the program:
* g++ myth-screensaver-proxy.cpp -o gnome-screensaver-command
*
* 3. Find what directory original gnome-screensaver-command is in
* (/usr/bin/ by default).
*
* 4. Look at your PATH settings (printenv | grep PATH).
*
* 5. copy binary buld on step 2 to any of the directories that
* come in PATH before original gnome-screensaver-command directory.
*
*/
