Linux Multimedia: Using Audacity to Remove Background Noise

Video isn’t the only media that Linux has made great strides in. Linux is routinely used by big sound and recording studios to record, mix and treat sound for movies and television. Although those tools can be expensive to own, the average user still had a plethora of utilities available that do many of the same things. Let’s take a look at one of the more popular overall sound packages called Audacity.

Download and Installation
In this case, the set up couldn’t be easier. As long as you have a functioning sound card/chip/USB speakers, then your distribution already has everything needed to work with sound except Audacity itself. Easy enough to rectify, let’s pull it down:
sudo apt-get install audacity
sudo yum install audacity


CentOS 7: An Introduction

Like our series of ongoing articles on Ubuntu 14.04 LTS, we are starting a series of articles on the recently released CentOS 7 distribution. Unlike Ubuntu, new versions of CentOS take years in between major versions. CentOS also supports their major releases for quite some time (see the table below). This first post will introduce some of the major changes to CentOS at a high level and then over the next month or so, we will discuss many of these changes in more detail. Let’s get started!

CentOS Support Timeline
Just as a quick overview, let’s take a look at the support life of each of the last major releases of CentOS (in general, seven years from release date):

  • CentOS 5.x – End of Life 03/31/2017
  • CentOS 6.x – End of Life 11/30/2020
  • CentOS 7.x – End of Life 06/30/2024


CentOS 7: Upgrading from CentOS 6.x In Place

One of the newest things added to CentOS 7 is the capability to do an in place upgrade of CentOS 6.x to CentOS 7. In the past, the only official method of upgrading major versions of CentOS was to wipe and reinstall everything. Having said that, there were always processes you could follow with varying levels of success (based on straying from the official repositories and how customized your setup and package list was). We have run through this process now about a half dozen times, with varying levels of success, so let’s talk about some of the successes and failures.

The Linux Interview: Technical and Practical Questions and Preparation

Congratulations! You are here because you landed an interview where Linux is either a key part or the entire focus of your prospective position. In this article, we are going to cover both practical (general interview) and technical topics that you can use to help you be prepared for that discussion.

Interview Checklist
We won’t spend a lot of time on general interview preparation, but it won’t hurt to go over a quick list of items to consider, bring or have prepared:

  • Notepad and Pen – this servers a couple of purposes. It will give you something to do with your hands (we all get nervous) and it will help you focus on the conversation, you can write down key points, items you have questions on or want to circle back to as well as things that you need to follow up on later
  • Dress Appropriately – many technical jobs have a more casual dress standard, however, you don’t have the job yet. Particularly if you have not asked, shirt, slacks and tie are minimum, a suit (male or female) preferred.
  • Research – do a little research on the company. There is a wealth of material available on most company websites, be sure to look them up. At the end of the interview when you are asked if you have any questions for them (standard end question), you can have one or two prepared that let them know you took the time to learn about what they do.
  • Be Early – sometimes it is not enough to be on time. Many times an interview will start with you needing to complete a formal application when you arrive. Get there 20 minutes early so you can get paperwork out of the way and start the conversation on time. Being respectful of their time is a key indicator of how you will be as an employee.


Ubuntu 14.04 LTS: Customizing Unity

Although the Unity Desktop Manager has made HUGE performance and usability strides since the initial release in Ubuntu 11.10, some people are still put off by a number of the limitations in customizing the look and behavior of the window manager. We are going to take a look at how to customize Unity and bring back a sense of control to your desktop.

Unity Customizations Available
In Ubuntu 14.04, Unity has several customizations that are available that were not previously. If you log into Unity, go the the “Settings” and choose “Display”, you will see the following screen:

Ubuntu 14.04 LTS Display and Unity Settings


Ubuntu 14.04 LTS: Codecs and Multimedia Updates

As part of the new LTS version from Ubuntu, some of the more “long standing” ways of doing things have changed just a bit. Multimedia and codec installation when using Ubuntu on your desktop has long been a staple of the “things to do after installation” crowd. A few things are different now (and a bit simpler), so let’s take a look at the lay of the land for Ubuntu 14.04 LTS.

A Quick Installation
The first thing you will want to pull down for your desktop environment is a common package for the more prevalent codecs. This is now more of a one liner whereas in the past it meant including this package along with a large number of others. In the case of Ubuntu 14.04 LTS, we can get most of what we want by doing a:
sudo apt-get install ubuntu-restricted-extras

Ubuntu 14.04: Hardware Compatibility Updates

As Ubuntu moves more and more spiritually away from being another “Linux” Distribution (check their site, the word Linux is not to be found, they have changed the language to refer to themselves as “the world’s most popular open source desktop operating system” instead), they continue to make efforts in certifying hardware from various vendors as “Ubuntu compatible”. Let’s take a quick look at some of the work that has gone into the Ubuntu 14.04 LTS hardware compatibility.

Linux and Oracle JDK: Add or Install

Although all distributions of Linux have access to a purely open source “Java” for application support and basic Java development (called OpenJDK with the IcedTea Java Compiler), we all know that there are certain pieces of the full JDK that are missing or have yet to be reverse engineered and release as purely open source. The OpenJDK functions nicely enough as a dependency for OpenOffice/LibreOffice and can even do a fair job of running Apache Tomcat if you choose, but performance can be spotty, garbage collection (memory management) needs work and it generally isn’t “officially” supported as a JRE for applications (or games) that require Java. That’s where this article comes in, whether you currently have OpenJDK installed and want to install Oracle’s JDK alongside or are doing a fresh install, we will show you how to correctly install the JDK using the new “/etc/alternatives” setup our modern Linux distributions are using.


Ubuntu 14.04 LTS: Major Application Updates

Over the last few weeks, we have been talking about the first new LTS version from Ubuntu in two years and some of the major changes to the operating system that you can expect to see once you take the plunge. Today, we are going to list some of the major applications available from the Ubuntu Software Center and the upgrades they have undergone since the last update to Ubuntu’s LTS OS.

Major Utilities and Tool Updates
In addition to the myriad major desktop application updates (which we will cover in the next section), there are a HUGE number of other utilities and tools that have received pretty major updates since the last LTS version a bit over two years ago. Let’s talk about a few:

  • Xen 4.4
  • This is a pretty major upgrade to Xen which is included with Ubuntu at this point. The most noticeable change to anyone who uses it will likely be that it no longer supports 32bit only CPUs (although 32bit client operating system support is still in place). This shouldn’t be a big deal since any modern processor in the last six or so years is 64bit, but it may mean that some people using Ubuntu on older servers or old laptops may need to be aware that Xen will no longer support their CPU family.
  • (more…)

Ubuntu 14.04 LTS User Interface: Menus and Window Decorations

In our last article, we casually mentioned a number of the changes that have taken place between Ubuntu 12.04 LTS and Ubuntu 14.04 LTS over the last two years. Several of those changes are either relatively radical departures from the the established User Interface that Ubuntu has been working so hard to establish with Unity or a complete change of heart since the first version of Unity way back in Ubuntu 11.10. With that release of Unity, it’s fair to say that Ubuntu was trying to shift the UI paradigm on the desktop, pushing it towards where they believed the mobile space was headed (how has that worked out for Microsoft?). Although today’s Unity is largely the same, there are some recent changes in the menuing and window decoration space that show Canonical was not entirely ignoring the user community. Let’s take a look at each.