[XviD-devel] Multithreaded Motion Search - looking for benchmarker

[Tom Jacobs]

sorry for the late reply,   just got back from holiday

here is the link to the paper that got stripped by the mailing list

http://www-staff.lboro.ac.uk/~eltrj/jacobstr_thread-level-parallel-xvid.pdf

hope this sheds light on all my questions to the list on the last year or so

Tom


Quoting Pascal Massimino <skal at planet-d.net>:

>
> 	Hello Bryan,
>
> On Wed, 2005-07-27 at 22:42, Bryan Mayland wrote:
> > While I was lying in bed the other night thinking about how much time
> it
> > takes to encode my 720x480 MPEG2 television recordings in 2-pass XViD,
> I
> > considered a processor upgrade.
>
> 	hey, hope it was just bad dream ;)
>
> > The algorithm creates a second thread to help with the ME, although
> > there is no reason this could not be increased further.  An array
> > [mb_width x mb_height] of "completed blocks" is initialized to 0, and
> an
> > array of "available blocks" is initialized to point to the block at
> > (0,0). Once the thread has completed the search, the block is flagged
> as
> > completed and then the algorithm checks to see if the block to the
> right
> > can be searched (which is true if block2's top right neighbor is
> > complete), and if the block to the bottom left can be searched (which
> is
> > true if block3's left neighbor is complete).  These blocks are added to
> > the "available" list.  If there are blocks on the list, the thread
> takes
> > one and starts again.
>
> 	This seems to me like a very good idea. Something
> 	equivalent is possible on the decoder side, too.
>
> 	Did you consider using a cascading condition/signal
> 	instead of using the array? Every row signals it is
> 	finished doing its current MB to the one underneath,
> 	which is possibly blocked at its condition (but
> 	fortunately not waiting for long).
>
> 	I would warmly recommend using the pthread API for that.
> 	There are a lot of equivalent to it under Win32.
> 	I could quickly crank up one if you want...
>
> 	very nice!
> -Skal
>
> (ps: @Tom Jacobs: unfortunately your attachment didn't make
> it to the ML. Do you have a replacement URL??)
>
>
>
>
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