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Archive for August, 2010

Unwanted Effects on my Line-in Interface

August 26th, 2010 No comments

Shortly after purchasing an xbox360, I wrote a short piece that gave instructions for forwarding your line-in audio through your pc speakers. By using this method and sharing my network connection, I’ve managed to run my xbox as a peripheral to my main computer setup, saving me space and money.

Lately however, the line-in loopback has not been working as expected. At times, it sounds like effects have been applied to the line. In particular, it sounds like somebody has applied a phaser or a delay effect to the input signal.

For the last week or so, I’ve been scratching my head about this issue, trying to figure out what part of my system may have applied effects to my loopback, but not to other audio on the system. Tonight, I was reviewing my original instructions for setting the thing up, and noticed that the module was being loaded on startup after being added to a system config file:

sudo sh -c ' echo "load-module module-loopback" >>  /etc/pulse/default.pa '

On a hunch, I took a look at the end of the file, and found the following lines:

### Make some devices default
#set-default-sink output
#set-default-source input
load-module module-loopback
load-module module-loopback

It looked like the instruction to load the loopback module had ended up in the config file twice! Because of this, the module was being loaded twice on startup.

So what does this have to do with the effects on the line? Well, if you play two copies of the same sound with a half-second gap between them, your ears will be tricked into thinking that you’re hearing one copy of the sound, but that it’s all echoey, as if a delay effect had been applied. If you repeat the experiment but this time decrease the gap between the two sounds even further, say to a few milliseconds, your ears will hear one copy of the sound with a phaser effect applied.

Essentially, when the module loaded twice, it was capturing the mix from the line-in port twice and playing back two separate copies of the audio. Depending on how close together these instances  were, the result sounded normal, phased, or delayed. I fixed the issue by removing one of the lines and then restarting the machine. This time, it started only one copy of the service, and everything sounded fine.

The moral of the story: If you’re loading modules at startup, make sure that you only start one copy of them.




On my Laptop, I am running Linux Mint 12.
On my home media server, I am running Ubuntu 12.04
Check out my profile for more information.

Trying out the Chakra Project

August 24th, 2010 1 comment

After a little bit of pressure from the people responding to my previous post (My search for the best KDE Linux distribution), I have finally given in and tried out Chakra. The Chakra Project starts with Arch Linux as a base but, instead of forcing you to build your own distro piece of piece, Chakra comes more or less pre-packaged.

Installation

The installation was one of the best I’ve ever seen. For alpha software this distribution’s first point of interaction is already very polished – even warning me that it is not stable software and might therefore eat my hamster.

The install process even let me decide to install some very useful packages, like Microsoft Core TTF Fonts and Adobe Flash, right away. Even the Language & Time step was incredible, offering a rotating globe that I could drag around and manipulate.

The only issue I had was trying to create a disk partition to install the OS to. This was because I was trying this out inside of VirtualBox, and the virtual hard disk did not have any partitions on it whatsoever. There is a bug and (thankfully) work-around for this known issue with their Tribe installer, and after reading a quick walk-through I was once again ready to install.

The Desktop

The desktop is standard KDE version 4.4.2 after install. Opening up Pacman (or is it Shaman?) showed me a list of brand new software that I could install, including the newest KDE 4.5. One of Project Chakra’s great strengths will be in this rolling release of new software updates. The concept of installing once and always having the most up-to-date applications is very intriguing.

Unfortunately, as with most alpha software, Shaman is still pretty buggy and often crashed whenever I tried to apply the updates. Also unfortunate is that Shaman started a trend of applications simply crashing for no reason. I don’t want to give this distribution a bad reputation, because it is still pre-release software, but I think it goes without saying that the developers have some bug squashing to do before a stable release will be ready. Something I found rather strange is that the current default software selection that Chakra ships with includes two different browsers, Konqueror and rekonq, but no office software whatsoever.

Google Chrome much?

Final Thoughts (for now!)

The Chakra Project looks very promising, albeit very unpolished at the moment. If they can manage to fix up the rest of the distribution, getting it just as polished feeling as the installer, this will definitely be one to look out for. I look forward to trying it out again once it hits a stable release.




I am currently running a variety of distributions, primarily Linux Mint 17.
Previously I was running KDE 4.3.3 on top of Fedora 11 (for the first experiment) and KDE 4.6.5 on top of Gentoo (for the second experiment).
Check out my profile for more information.
Categories: KDE, Linux, Tyler B Tags: , , ,