Between Linux and Anime

Mplayer and Kaffeine and such work perfectly fine (which means codecs are properly installed)? Getting irritating and inexplicable errors like these?

main decoder error: no suitable decoder module for fourcc `mpga’.
VLC probably does not support this sound or video format.
and/or
main decoder error: no suitable decoder module for fourcc `mpgv’.
VLC probably does not support this sound or video format.

I have absolutely no idea why this happens, but apparently the VLC that comes with some common repos for OpenSUSE (I think I got this having installed from Packman!) is somewhat borked. Want a working VLC? Grab it from the Videolan repo. I installed that in desperation and all was suddenly right with the world.

(I half didn’t want to make this post since I can’t actually explain what the problem is and am too lazy to find out, but this solution needs some Google love, so here)

Unable to play that 1080p video without lagging? Wanna watch that 720p video file on dated hardware? Well here’s something you can try. Basically the default behavior of most video players is such that they only hog a single core while doing video decoding. If we also commit all the other available cores to the task, well, we’ll of course expect to get better performance. You won’t get double or triple the performance of course – things don’t work out that simply. The difference is noticeable though.

This isn’t a new method. However, the old instructions don’t seem to work anymore – the ffmpeg-mt branch no longer seems to build with mplayer without non-trivial modifications. Fortunately, all the improvements in the ffmpeg-mt branch have recently been merged into the main release. So we can now use the main release instead.

1. Grab the mplayer source:

   svn co svn://svn.mplayerhq.hu/mplayer/trunk mplayer

2. Grab the source for the latest ffmpeg release here. The version I tried is the latest one as of the writing of this post: 0.9.1. Simply download and extract the ffmpeg folder into the mplayer folder from the previous command.
3. Now build mplayer:
   

   cd mplayer
./configure
nice make -j 4

4. And install it as ‘mplayer-mt’:
   

   sudo install -m 755 mplayer /usr/bin/mplayer-mt

Now you can use mplayer-mt to play more performance-intensive videos and should perceive a noticeable improvement, assuming you have a multi-core processor. If you use a GUI frontend like smplayer, look for an option that lets you specify the mplayer executable, and replace it with mplayer-mt.

Unfortunately I have no idea if anything similar is possible with VLC. If you do, kindly let me know at the comments.

Everywhere across the Internet you’ll find “answers” to this question that tell you to do gksudo and kdesu and if you’re like me you get by by working around your problem in some way that lets you gksudo or kdesu – until that one time when it just doesn’t cut no matter which way you slice it. That time is now for me, and what a surprise, it’s a damn pain in the neck to actually dig out a solution from amidst the mountain of “use gksudo/kdesu”s.

So here’s me penning this post to hopefully help combat the million other gksudo/kdesu posts out there – because sometimes, you need stuff run – graphically and as root – when you’re not around to type a password.

Solution is surprisingly simple. Your X display is normally loyal only to you (the user) and will not answer to any other user, not even root. If you tried to run a graphical application from a rooted terminal, it’ll say something like the following:

X11 error: Can’t open display :0

Which is your application’s plaintive cry at being shut out by X. So to get around this, you basically just need to tell X to stop doing that. Like so:

xhost +

Run it as your regular user (X normally ignores everyone else remember?). And that’s it! Try it. Open a terminal, su, and open firefox or something.

PS: yes I’m not dead yet, and yes I still haven’t finish that blasted Eva post I’ve been sitting on for ages ;_;

Just gonna pen a quick note. Smplayer, the pretty great Qt-based frontend for mplayer that I use, started behaving strangely after I performed a recent software update. Symptoms are – video plays, but does not respond to common keyboard commands like ‘f’ to full-screen and arrow keys to skip. Also, the GUI becomes unresponsive – you can’t click anything. I didn’t spend too much time looking up the source of the problem, but it may be related to this.

I’ve discovered you can workaround this annoying problem by installing mplayer2 and then configuring smplayer to use that instead of mplayer. Simply install mplayer2 via yast or via

sudo zypper install mplayer2

Then start smplayer (without arguments! If you load it with a video the UI will freeze!) and go to Options > Preferences > General > General and key in “mplayer2” for the field “Mplayer executable:

While there are some differences between mplayer2 and mplayer, everything appears to work fine using it with smplayer so far, so I’m pretty happy.

Okay, I’m gonna post this in here once and for all, if for nothing more than my own recording purposes. So the somewhat sticky problem of multiple-monitor configuration is getting very nice and shiny new GUI’s in Linuxland nowadays. KDE Plasma 4.6, for example, has something like this:

Very lovely. The vexing thing however is that it doesn’t have “full control” so to speak. It’s likely a xrandr frontend, and that’s all nice and good except that if your Xorg config isn’t set up right, no configuration actually works, except for cloning, which clearly isn’t the most useful set up around. It turns out that you need to set the maximum virtual screen size to a value larger than required for your set up. For example if you’re configuring a 1280×800 desktop and a 1440×900 desktop side-by-side, you’ll need a virtual screen size of at least 2720(1280 + 1440)x900, and if they’re stacked vertically you need at least 1440×1700(900+800). How do you set the virtual screen size? Open /etc/X11/xorg.conf in your favorite editor as root:

sudo nano /etc/X11/xorg.conf

And under the “Display” subsection of the “Screen” section, add a “Virtual” line with your desired virtual screen dimensions as arguments. Example:

Section "Screen"
	Identifier "aticonfig-Screen[0]-0"
	Device     "aticonfig-Device[0]-0"
	Monitor    "aticonfig-Monitor[0]-0"
	DefaultDepth     24
	SubSection "Display"
		Viewport   0 0
		Depth     24
		Virtual		3000 3000 # <-- ADD THIS LINE!
	EndSubSection
EndSection

And you should now be able to configure your multi-head set up with xrandr or with your preferred graphical frontend (in KDE Plasma 4.6 the frontend is at System Settings > Display and Monitor > Size and Orientation).

You know what the worst thing is? Software updates sometimes rebuild your Xorg.conf, overwriting your changes, which means that you may need to repeat the above again after certain updates. That’s what just happened to me, so I’d keep this page (or whatever other page on this problem you find) bookmarked.