multithread & veejay : openmp test

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d.j...@free.fr

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Dec 19, 2016, 11:30:21 AM12/19/16
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Hello folk of the last pixel,


I have successfully tried to introduce OpenMP [*] (parallel programming) to veejay on the effect side (libvje).
I have selected "Constant Time Median Filter" as test. Even with a 2 years old cpu this effect do not run at realtime.

So, using the "sections" omp distribution, the YCbCr channels work is distributed nicely among ones material resources... great!

But,
do to the overhead of thread creations and join, for each apply of the filter, finally the effect run slower!

Any idea to get ride of the overhead ?
Any idea for a good use of openmp usage in veejay ?

[*] http://www.openmp.org/

Matthijs van Henten

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Dec 19, 2016, 2:13:48 PM12/19/16
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Looks like copying data between the treads is costing you? I don't know much about openMP or (c for that matter, 1 semester of cs) but looks like you could use the shared memory feature of openmp to speed things up.



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