I just spent almost two hours hacking away at the Banshee visualization pipeline again and made one very important optimization: when the callback function is null (which happens when nobody in managed land is listening for visualization data) the visualization pipeline is effectively disabled. The only element that remains active is a queue, which provides a 5-second buffer so that visualization can be quickly resumed.

The patch is now over at GNOME’s Bugzilla, just waiting. Waiting for Aaron to commit it. Waiting for a chance to prove it’s all grown up now. Hoping to bring joy to audio enthusiasts all around the globe.

Yeah, I did watch Tommy Boy recently. … Why?

After ruling out a few things I discovered the root cause. In OpenVP, PCM and spectrum data are represented as 32-bit floats, which means that the pipeline needs to convert whatever the audio format is into this one. Along the way it resamples the stream too, to provide a consistent frame rate of consistent-size slices. 512 samples 60 times per second is 30720 samples/sec. If anyone can show me a song found in the wild encoded at this rate I’ll give you… well, nothing, since I’m a college student and couldn’t afford to give you this pencil I have sitting on my desk.

Anywho, the conversion to float cannot be avoided but the resampling can be. By setting it to the more common 44100Hz sample rate CPU usage dropped to 4-6%. It’s pretty cheap to convert formats and throw duplicate data around, but interpolating data is a lot more expensive.

At some point the vis pipeline will be smart enough to split music into chunks of a size depending on the current sample rate. Until then this patch should be good enough. (I hope.)

I don’t know what they put in the water either, but I bet Obama can fix it with his amazing super change-bad-stuff powers!

Much work still remains to be done, but what I have is a pretty stable foundation. Both the OpenVP 0.0.1 branch and Banshee.OpenVP are available over at the Google Code repo. They should both be stable enough to test, but since the build system isn’t in place yet I’m not asking the general public to try it out yet. But if you know your way around MD, autotools, and Banshee you might be able to get it working. (Please don’t ask for help with that part yet. If you get it working and hit a bug please let me know though.)

Right now I am getting ready for the 0.0.1 release of OpenVP. The version number is intentionally scary; the API is far from stable and will be changing rapidly. The purpose of this release is to provide a stable target for the Banshee extension. Hopefully getting this in Banshee will generate interest in OpenVP, as well as giving Banshee some cool eye-candy. Everybody wins!

My understanding is that after OpenVP 0.0.1 is released and the Banshee.OpenVP extension is finished (it’s proof-of-concept quality right now) it will be absorbed into the Banshee source tree and maintained over there. Which means it will likely come with Banshee 1.4 by default. Awesome.

(Oh, and OpenVP has migrated from my personal Subversion repository over to its own Google Code project.)

Here are the present contents of the album, sure to grow as our shenanigans continue:

We use an XML editor named Epic (well, I don’t but other people do). I saw a few books on the bookshelf and couldn’t resist.

There’s been this hole by the baseboard of a wall here. Jason finally did something creative with it. (And I captioned it.)

Did Delicious hire the Twitter engineers, or what?

Let me explain something. “Error” is not a verb. You can’t error. It’s not possible. When you type “erroring” it has a red wavy underline for a reason.

You can err. “Erring off” is at least valid English, but I’m not sure what purpose the “off” serves. “Erring” works by itself.

Or you could just use one of the industry-standard terms, like

• crashed,
• failed,
• went down, or
• is unavailable.

As a bonus, most of these actually convey the nature of the problem. The only information “erroring off” conveys is that you not only don’t know exactly what went wrong, but also have a substandard grasp of the English language.

Almost 25% of visitors use some version of IE and 44% use Firefox. (20% did not identify their browser.) This is rather astounding to me. Apparently either FF gained more market share than I thought or this blog tends to attract the kind of people who use FF (probably the latter). Mozilla, Opera, and Safari are straggling at 5.7%, 3.3%, and 1.4% respectively.

Out of the 25% using IE, the usage is almost exactly split between IE6 and IE7, with IE7 almost a full 1% ahead. Can someone please explain why people are still using IE6? Seriously people, this is 2008.

Firefox >= 3.0 accounts for a little over half of all FF traffic with various versions of 2.0 making up for most of the difference and a negligible amount of 1.0 and pre-1.0 hits making up the rest.

When it comes to operating systems, almost 54% are using Windows, 21% Linux, 3% Mac OS X, and 22% unidentified. Windows XP wins with 40% overall usage and Vista can claim 7%. Most of the Linux hits didn’t identify the distro.

The search robot report is interesting. From the major search engines, Google was the most conservative, making 236 hits for 2.83MB of data. MSN hit 975 times for 9.71MB. The winner is Yahoo: 2057 hits for a whopping 27MB. I’m not quite sure why Yahoo needs so much… Google seems to keep up just fine while consuming only a tenth of what Yahoo does.

Not surprisingly, the most popular blog posts are not about my own projects. The most viewed one by far was a gripe about gnome-terminal. Seems many people have the same irritation that I do.

So yeah. I don’t really have any point to make, except possibly that people should not be using IE6 anymore, and some search engines should really optimize their crawlers better.