Linux, musical road-dogging, and daily life by Paul W. Frields
 
Practicing what I preach.

Practicing what I preach.

When I first tried Ogg Vorbis, the free and open-source codec for compressed audio files (think “like MP3”), I was unimpressed. That was several years ago. At the time, even many MP3 compression utilities were using a substandard version of the MP3 codec — Xing springs to mind. These versions would literally cut off all frequency response over 14kHz to concentrate on “more important” (the term’s not my idea) material to which most people pay more attention.

The LAME codec made great strides in taking care of this problem by taking the ISO MP3 code and building thereon. In the latest versions, the ––preset standard option produces very good results, but still uses a low-pass filter between 18.8 and 19.2kHz to similarly concentrate on more audible material. (The higher the frequency in MP3, the more of the file is required to address the audio compression, so it’s possible to compromise the audio at low frequencies if the codec concentrates on reproducing higher ones more faithfully.)

In those days, Ogg Vorbis was more useful for very low-bandwidth applications, when it performed better than MP3. This was a boon for people on dialup Internet, but not as good if you had significant hard disk space to devote to an audio library.

Now all that has changed. I sat down at the computer and did some cross-comparisons of MP3 and Ogg Vorbis, and can say with a great degree of certainty that at similar file sizes to MP3 using ––preset standard, Ogg Vorbis kicks LAME’s hindquarters. I find that a quality level of 0.65 results in files that are roughly the same size — a fraction smaller, actually — as an MP3 at the aforementioned preset, but with far better high frequency reproduction and no apparent loss of quality at more fundamental frequencies.

The MP3 format was one of my last reliances on non-free codecs, and I still have to keep it around to support my wife’s Philips Nike PSA portable audio player, which only supports that format. However, the next purchase we make will be of an audio player that supports Ogg, and I’ll be converting my audio library to that format. The switch is of little consequence to me (other than the time spent re-ripping), since I still get my music the legal, old-fashioned way.

I’ve updated my gstreamer plugin configuration page under the Fedora Fun section to reflect this change. I’ll no longer encourage people to use proprietary plugins for this application, since it’s now unwarranted as far as I can tell.

2 Comments

  1. i need to find an app that does realtime conversion from one format (Ogg) to another (mp3). then i will jump on the Ogg bandwagon. i have a couple of older mp3/wma players which network (via 10M ethernet, albeit) to a PC fileshare.

    brings up a point. i’ll have to see what i can get for those players on eBay. if it’s >$75, then i’ll part with them so i no longer have this block.

    i have a win2k server i wouldn’t mind converting to FC4, save for 3 issues:

    1. the aforementioned mp3 players require a service that runs under win. i believe there may be a linux version, but i’ve not cared to investigate, what with planning a wedding, honeymoon, renovating a house, work and church responsibilities…. should i get rid of the players, then this req. is removed.

    2. drivers for the RAID 0 card i have installed. at the time i installed it, no linux drivers existed. i have had less than ideal performance under windows (system locks up from time to time) due to this card, so i wouldn’t mind scrapping it and demirroring the drives, and just setting up a cron to archive the live disk to the backup.

    3. the video card. it is an old ATI all-in-wonder 128 AGP. i’m sure there’s drivers for the video portion and maybe even the TV tuner. i use this PC to watch TV while working at times. don’t really use the VCR function, but would like to do so in linux. i know there’s a TV app in linux. any thoughts?

    additionally – playing/burning DVDs in linux. haven’t tried. thoughts on this?

    tnx.

  2. The conversion is easy, but you have to be willing to suffer the consequences of converting from one lossy format to another. I would bet that if you keep the first-gen copy as Ogg with a quality q=0.65 or higher, you won’t notice much of a quality drop (if any) if you transcode to MP3 at CBR 128k. That part’s easy. In Linux, you’d just do:

    oggdec -o - file.ogg | lame - newfile.mp3

    1. Ah, the perils of vendor lock-in.
    2. Don’t know what card it is, but you could always try software RAID under Linux instead if it was a concern.
    3. I’m sure you will have no problem doing this. There are even distros that are built to act like Tivos nowadays, or you can get apps to run under FC4 to do it.

    As for playing DVD’s, well, there’s the rub. You have to go outside the free software arena to do this, thanks to MPEG software patents. (Repeat after me, software patents are BAD.) But you can find plenty of repositories for yum that offer this software. See FedoraForum.org or FedoraFAQ.org for more information.

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