[vorbis-dev] Parallelism

[Jeff Squyres]

On Thu, 17 Aug 2000, Gregory Maxwell wrote:

> Because it's trivial to parallelize vorbis effectively for all
> sensible workloads using pmake and the stock encoder. Why burden the

I claim that starting a bunch of encoders on a bunch of tracks is
suboptimal.  See http://www.xiph.org/archives/vorbis-dev/1098.html.

> software when it's still under active development.

One good reason is that at least a preliminary look shows that it *MIGHT*
be possible to do this completely within the encoder -- i.e., no changes
would be required in libvorbis.  Again -- this is a *preliminary* look; no
guarantees here.  But it certainly would be nice, and make the parallelism
pretty easy.

Another reason is that using pmake is not easy for most users.  Sure,
every developer worth their salt knows how to use pmake.  But most users
do not.  

Also, does pmake work under windows (I honestly don't know)?  There are
multiple freeware implementations of MPI that work with windows as well as
freeware and vendor-supplied implementations of MPI for POSIX-like
environment; an MPI solution is truly portable to any modern parallel
resource.

Finally, wouldn't it just be nice to do:

        ogg encode -parallel *.wav

and have it do the Right Thing to branch out across lots of CPUs/nodes?
I'm simplifying a bit here, but it could be easier to run MPI codes --
something that common users have been shown to be able to handle -- than
to run pmake.  This is also a pretty subjective argument; someone else
might just as easily say, "you're wrong".  :-)

> If you really have a reason to want this feature, then you have enough
> of a reason to code it yourself.

I already volunteered to do it.  :-)

Don't get me wrong, but isn't this one of the ideas of what open source is
all about?  The core developers continue the Main Work while specialists
and other outside developers can add some fun/useful bells and whistles on
the side.  

{+} Jeff Squyres
{+} squyres at cse.nd.edu
{+} Perpetual Obsessive Notre Dame Student Craving Utter Madness
{+} "I came to ND for 4 years and ended up staying for a decade"

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