[vorbis-dev] Parallelism

[Adam Scriven]

At 16:47 2000/08/16 +0200, you wrote:
> > On Wed, 16 Aug 2000, Adam Scriven wrote:
> > > [snipped]
> > > advantage of it (I want to do this for my CD collection, too.  Got some
> > > spare 486's kicking around. 8-) ).
> >
> > This was the motivation for parallel bladeenc -- I just got tired of
> > waiting around for my CDs to be encoded.  :-)
>
>The slower part of encoding cd's to mp3 is ripping the cd's. At least, my 
>best cdrom player rips cdda only at 11x speed.

That is not at all my experience.
I can rip a track from a CD faster than any machine I have can encode it.
Generally, the ripping takes, say, 30 seconds, but the encoding takes 
minutes, all the time.
That's why, if you see the MP3 ripping/encoding programs, that the encoding 
is always a forked child, because it takes MUCH more time than ripping 
does.  It's also much more CPU intensive.

> > > Is the coding required for parallelism detrimental in for single-CPU
> > > uses?
> >
> > Not sure what you mean here...
>
>He means if the 'normal' code gets any slower.

Yup, that's exactly right.
Is it any slower on a non-parallel machine.
This is, of course, assuming that you Couldn't do it with a command line 
switch, which Jeff already said you could.  So it's moot now.
8-)

>I would suggest making separate source files for 'multi' encoding, calling 
>the correct 'single' routines. Probably the program flow will be different 
>from the 'single' encoder.

This isn't a bad idea, but if it can be configured with a command-line 
switch, why not combine them.  Have it off by default, but if you want, 
ogglame --parallelize would turn on the parallelizing code.

Thanks!
Adam

Toronto, Ontario, Canada

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