Sep 172006

I mentioned in a previous post that I was looking for a web applet for playing FLAC audio. This search still continues, however, in the meantime I’ve gone ahead and set up the site to use a browser plugin instead, with a fallback letting people download the files manually.

So now, we’re now open for business, and seeking people with good hearing and some time to spare, to help us out in this survey.

This is part of a group project for university. I intend to keep the project running as long as I can. For the purposes of this assignment, I need some data by Friday, the 22nd of October. I intend to make the results of this survey publically available.

To do the test, you’ll need:

  • A player or browser plugin supporting the MP3, Vorbis, AAC and FLAC formats. (Such as mplayerplug-in with the FLAC support patch)
  • A broadband internet connection (if streaming)
  • A decent sound system
  • Low/no ambient noise

Those wishing to participate, please see the project homepage.

  2 Responses to “Codec Survey: Listeners wanted for codec comparison”

  1. One minute I was reading about autism (my girlfriend thinks I have aspergers) and the link to mercury fillings – the next I am conducting a sound test – only I am not – because I use Safari web browser on a Mac and can’t playback your ogg files.

    I am a sound engineer with a lot of experience with audio codeds and if anyone can tell you anything about your files, I can. However, I don’t think that dwonloading the files and allowing the end user to play the file back in a random player is a good idea as players render the file in different ways. You have also made no provision for sound cards and the fact that some sound cards filter playback – audio drivers, multimedia drivers render audio in a different way to directx drivers and what about Apple computers, Linux users et al. I would love to participate – but you need a better test!!!

  2. This is true… the ideal situation would be a web applet, which at least removes some of the error, but not all of it — I still have to contend with differences in DACs, amplifiers, operating system, driver version…etc. Also the encoder plays a significant part… LAME apparently isn’t great at low bitrates, and my version of FAAC doesn’t like encoding below 112Kbps.

    However, I feel this will make only a subtle difference, compared to the difference between using different bitrates.

    Also bear in mind that the subject in question is part of my Electrical Engineering course, and I’ve been seeking fellow students to do the test. Not all of these people are as computer literate as one might assume. In addition to this, I personally have no idea what sort of sound card is soldered onto the motherboards of the university computers. So there’s all sorts of issues in trying to collect this information.

    Probably worth noting, is that I’ve also used analytical methods to assess the quality, namely the humble FFT, which allowed me to calculate the level of attenuation in different frequency bands. This project is more than just audio quality, I’m also looking at encoding time, decoding time (CPU time that is), compression ratios…etc. These tests were conducted on my P4M 1.7GHz laptop, under controlled conditions.

    On using Safari for the test… you should be able to use QuickTime if you install the XiphQt extension . You may also be able to coax MPlayer Plug-in to work (Mac OS X being a Unix clone), but I don’t know what Safari’s compatability is with Netscape plugins (being KHTML-based, they may work though).