[vorbis] Comparison Between MP3 and Vorbis

Michael Smith msmith at labyrinth.net.au
Thu Apr 13 01:48:33 PDT 2000

>CPU time for playing is much, much too high. There may be
>inefficiencies in the XMMS plugin or in the libvorbis library. I do
>not know which to blame.
>Is the efficiency playing Vorbis/.ogg files expected to improve? Is
>that just an artifact of being pre-release, unoptimized code?

The XMMS plugin isn't particularly inefficient. Libvorbis is clean, working
code - but it hasn't been optimised at all yet, really. Functionality
before speed! 

On the other hand, 50% cpu seems overly high. This machine takes around
4-5% cpu to decode an mp3 (similar to what you were seeing). Right now,
vorbis comes in at around 25% cpu time - still not great, but better than
what you're seeing, and quite tolerable. I was seeing around 50% cpu usage
with a debug build, full optimisation cut this almost in half. 

The decoding complexity shouldn't increase in the future, as I understand
things, so this should be an upper limit on what decoding will take.

There are a number of obvious places which could be optimised - but it
really isn't time for that right now. At this point, clarity and
completeness are far more important. Eventually, an optimised decoder
should be of comparable speed to an mp3 decoder, or at least not much slower. 


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