Hitchhiker's Guide to Openbsd

Audio formats using lossy compression (Ogg Vorbis, MP3, WMA, AAC)
http://www.openbsd.org/faq/faq13.html (5 of 25)9/4/2011 10:02:21 AM

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13 - Multimedia
Lossy compression methods are often used for audio or other media files. The idea is that an amount of 
data is thrown away during compression, but in such a way that the compressed result is still very usable 
and has a good enough quality to be played. The advantage is that these techniques enable much higher 
compression ratios, resulting in reduced disk space and bandwidth requirements. 
A good example is the free, open and unpatented 
Ogg Vorbis
 format. To play Ogg Vorbis files, you can 
use the ogg123 utility, which is bundled in the 
audio/vorbis-tools
package. For example: 
$ ogg123 music.ogg
Audio Device: Sun audio driver output
Playing: music.ogg
Ogg Vorbis stream: 2 channel, 44100 Hz
Time: 00:02.95 [02:21.45] of 02:24.40 (133.1 kbps) Output 
Buffer 87.5%
Of course, Ogg Vorbis plugins exist for many other audio software. 
Another example is the very popular MPEG-1 Audio Layer 3 (MP3) encoding, which has, however, its 
share of licensing and patent issues. Many tools can play MP3 files, just have a look through the 
audio
section of the packages and ports system and pick one you like. 
How about the proprietary Windows Media Audio (WMA) format? Files of this type can be played 
using 
x11/mplayer
which uses the 
FFmpeg
 framework. 
A good starting point to learn more about different audio file formats is this Wikipedia article: 
Audio file 
formats
. 
Synthesized sound
MIDI
The Musical Instrument Digital Interface (MIDI) protocol, is handled by 
MIDI devices
. If you don't 
have a MIDI synthesizer, but you wish to play a standard MIDI file (SMF), you can use software to 
render MIDI data, generating audio files. By default, the 
audio/timidity
port renders MIDI files 
and play them on the audio device: 
$ timidity file.mid
MOD
http://www.openbsd.org/faq/faq13.html (6 of 25)9/4/2011 10:02:21 AM

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13 - Multimedia
A Soundtracker module is a binary format that mixes audio samples with sequencing orders, making it 
possible to play rather long pieces of digital music with reasonably good quality. 
The easiest way to play your favorite MOD files on OpenBSD is probably to use the XMMS software, 
available through packages and ports. You should install the 
-mikmod
subpackage for XMMS to let it 
use the MikMod sound library, which supports the MOD, S3M, IT and XM module formats. 
You will also find a number of so-called "trackers" in the 
audio
section of the packages and ports 
collection, e.g. tracker, soundtracker. With these trackers you can not only play but also generate your 
own modules. Note, however, that not every tracker format is supported by the tools in the ports tree. 
You are always welcome to 
submit a port
of your favorite tracker software.