Quick Fix: Unity sidebar and panel are missing!

The jury is still out on the Unity desktop for me. I certainly didn’t need to switch away from Gnome, but I’m a long time supporter of Ubuntu so I’m giving it a go. But when I was messing around trying to get a PS3 SixAxis controller working with Portal 2 today I managed to make the sidebar and panel disappear. What’s more, Alt-F2 wasn’t bringing up the run command dialog. Luckily I had Guake running so I was able to use the virtual terminal.

Now if you search around, a lot of folks will tell you to run “unity –replace”. This made the windows jump around but didn’t fix the problem. On Lucid I would have restarted Gnome, calling the gdm daemon to restart. But there’s no¬†gdm here. I searched around on that topic and found that gdm has been replaced by lightdm. So, if you hose your Ubuntu 11.10 desktop UI and need to reset it (without rebooting) use this new command:

sudo service lightdm restart

I hope this is helpful!

Quick Tip: Pause any process you want in Linux

 mike@krusty:~$ pidof ffmpeg
 mike@krusty:~$ sudo kill -STOP 22730
 [sudo] password for mike:
 mike@krusty:~$ sudo kill -CONT 22730

Holy crap, how come it took so long for me to figure out you can pause a running process in Linux and restart it later? I was looking at the manual page for the kill command (man kill) when I started wondering what the CONT option is used for. It turns out that it is paired with the STOP option (and a couple of others) which can be used to pause a running process. Here’s a quick rundown of the process:

  1. Find the PID of the process using the ‘pidof’ command
  2. Pause the process using that PID (22730 for example): sudo kill -STOP 22730
  3. Go about your business
  4. Restart the process when you’re ready: sudo kill -CONT 22730
What can you use this for? Well, if you’re doing something processor intensive, like transcoding video, you might want to regain your CPU power for a quick task. This lets you do that.

One terminal command puts your recipes on iPad

Amanda and I cook our own meals the vast majority of the time. She’s much better at it than I am, but I do well if I have a good recipe to follow. The problem is that our growing pile of printed-out recipes was getting out of control. The solution was to use a digital recipe system, and I figured out how all of my recipes can be on the iPad (or just about any other web-enabled device) with a simple terminal command. I’ll share how I did it after the break.

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Rendering video with Cinelerra and FFmpeg

I’ve been making videos to share with posts and looked around for some video editing software that works with Ubuntu. I’m running 11.10 Oneiric Ocelot and Avidemux is not yet in the repositories so I decided to give Cinelerra a try. It’s availalbe in a PPA.

I like it. I’d guess it’s got a 2-4 hour learning curve but after you figure out what commands and clicks control each function it’s pretty easy. The problem came when it was time to export my video to post on YouTube.

I tried exporting OGG files, but I got some weird errors, and only part of my video would appear when uploaded to YouTube. I needed to find an alternative. Since I’ve already compiled FFmpeg from source for transcoding my over-the-air recordings it seemed like a good choice for rendering the videos outside of Cinelerra. All I needed to do is get my hands on the raw audio and video, then use FFmpeg to assemble the parts. See the steps I took after the break. Continue reading