Cooking with Linux - Let Me Show You How It's Done with a Little Video
Usually, the reason for doing this converting, is to provide videos that your friends running another operating system can view. Or, you could direct them to download OGG codecs instead, so they will be able to enjoy completely free video and audio.
The next item on this star-studded menu, is John Varouhakis' recordMyDesktop, a desktop screencasting program that includes both a command-line tool and a graphical front end, gtk-recordMyDesktop. You can pick up a copy of gtk-recordMydesktop from recordmydesktop.sourceforge.net. For the purpose of this demonstration, I concentrate on the graphical client rather than the command-line version.
When you start gtk-recordMyDesktop, a simple recording dialog appears (Figure 3). On the left-hand side of the program, there's a preview pane with a button labeled Select Window directly underneath. Before you begin recording, click the window you want to capture. You'll see it outlined in red in the preview pane. To record the whole desktop, click on an empty (or shall we say, uncluttered) portion of your desktop. Adjust video and sound quality using the sliders on the top right. To begin recording, click the red Record button. When you do that, the dialog vanishes.
If you are paying attention, you might notice something that looks a little like Istanbul here. It's that little red circle sitting in your system tray. This similarity isn't entirely accidental. Parts of Istanbul are in gtk-recordMyDesktop. Incidentally, another way to start a recording is to click the red system tray icon. It then changes to a gray square while you record your session. When you click it again, the recording stops and you return to the gtk-recordMyDesktop window. Although there's no preview of your recording, you can save it by clicking the Save As button.
Let's take a closer look at another part of the interface, the Advanced settings. Clicking the Advanced button brings up a more comprehensive settings dialog with four tabs (Figure 4). In Figure 4, I've highlighted the Performance tab, which controls frames per second, on-the-fly encoding and more. Changing settings here makes higher quality screencasts possible, but keep in mind that doing this impacts system performance, and you may require more horsepower to achieve good results.
The Files tab has two functions. It allows you to define your working directory (/tmp is the default), and it lets you decide whether you want to overwrite files as they are recorded. The resulting videos are saved to out.ogg. Subsequent writes will use out.ogg.1 and so on. If you would rather have gtk-recordMyDesktop overwrite the file each time, check the appropriate box on the Files tab. Under the Sound tab, you can change the number of audio channels, the frequency and the audio device location. Finally, under the Misc tab, you'll find primarily visual settings, such as the appearance of the mouse cursor in your videos.
What's an article on screencasts without some screencasts to watch? To see these tools in action, visit Marcel's site at www.marcelgagne.com/ljscreencast.html.
For the KDE users out there, Marios Andreopoulos has created reKordmydesktop, a feature-rich and fantastic front end to recordMyDesktop. This program is a single Kommander script, and as such, it doesn't require a complicated installation, but you do need to have Kommander installed. Save the file to your desktop (or any location you please) and click on it. The reKordmydesktop dialog (Figure 5) appears, ready to do your bidding.
As you can see, the GUI does add some great flexibility, starting with a definable location and name for your OGG file. Everything you need is covered under these three tabs, although most of what you'll want is on the Common Settings tab. Let's look at a few of those, starting with sound. To record audio, make sure you click the Capture Sound check box. You can specify a time delay to your recordings—you can screencast reKordmydesktop, so you may want to minimize it first when capturing the whole desktop—or set a time limit on the recording (look in the Chrono section). By default, reKordmydesktop captures the entire desktop. To select a window, click the Grab Window button on the left, and click on the program window you want to capture (again, you even can click reKordmydesktop if you choose). To start recording, simply click the Record button.
One thing I like about this program is that you can pause a recording, change things around, then continue by clicking Pause again. When you are done, click Stop, and the OGG file is written to disk.
Let's have another look at that three-tabbed interface. Under the Encoding Settings tab, audio and video settings can be changed and tweaked to give you a recording that balances your system's performance to provide the best quality possible. This might include dropping frames, selecting multichannel audio or choosing a higher sampling rate. The Advanced Settings tab allows you to select an alternate cursor (or none), change the working directory and more. If you think you've gone and changed things for the worse, there's a handy Restore Default Settings button here as well.
And that, mes amis, is what we call a wrap. The system clock, sadly, does not lie, and closing time is nearly upon us. I invite each and every one of you to try your own screencasts. Post them to your blogs, Web sites or even YouTube. Show others how much fun Linux and open-source software can be. In the meantime, perhaps François will be so kind as to refill your glasses once more. Until next time, please raise your glasses, mes amis, and let us all drink to one another's health. A votre santé! Bon appétit!
Practical Task Scheduling Deployment
July 20, 2016 12:00 pm CDT
One of the best things about the UNIX environment (aside from being stable and efficient) is the vast array of software tools available to help you do your job. Traditionally, a UNIX tool does only one thing, but does that one thing very well. For example, grep is very easy to use and can search vast amounts of data quickly. The find tool can find a particular file or files based on all kinds of criteria. It's pretty easy to string these tools together to build even more powerful tools, such as a tool that finds all of the .log files in the /home directory and searches each one for a particular entry. This erector-set mentality allows UNIX system administrators to seem to always have the right tool for the job.
Cron traditionally has been considered another such a tool for job scheduling, but is it enough? This webinar considers that very question. The first part builds on a previous Geek Guide, Beyond Cron, and briefly describes how to know when it might be time to consider upgrading your job scheduling infrastructure. The second part presents an actual planning and implementation framework.
Join Linux Journal's Mike Diehl and Pat Cameron of Help Systems.
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With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
This ebook takes a look at some of the practical applications of the Linux on Power platform and ways you might bring all the performance power of this open architecture to bear for your organization. There are no smoke and mirrors here—just hard, cold, empirical evidence provided by independent sources. I also consider some innovative ways Linux on Power will be used in the future.Get the Guide