What I think is the correct fix is posted as https://github.com/OpenImageIO/oiio/pull/2333 <https://github.com/OpenImageIO/oiio/pull/2333>
My bad. For 2.0, we changed the APIs to make them stateless (thus thread-safe) and that pushed a call to seek_subimage into the implementation of read_native_scanline. But for DPX in particular, seek_subimage did not bother to check for the trivial case of whether it was being asked to seek to the subimage it was already pointed to, so a whole lot of additional work was done on every single scanline. We use DPX a lot, I'm shocked nobody noticed this. Though I think it's worse on Windows, and MUCH worse if you are very heavily threading. So maybe a couple seconds on a DPX read went unnoticed for script-based processing. I will work on setting up some new performance tests that I hope will catch important performance regressions in the future. > On Sep 4, 2019, at 1:58 PM, Larry Gritz <[email protected]> wrote: > > Stand down, everybody. I have tracked it to the particular command, > understand it now, and I have a proper fix. > I'll submit a PR today. > > -- lg > > >> On Sep 4, 2019, at 1:51 PM, Renaud Talon <[email protected] >> <mailto:[email protected]>> wrote: >> >> > I'm digging into it on my end. If you test other version tags (such as >> > 1.8.17), I'll be curious to hear the results. >> >> I compiled 1.8.17 and ran this command again: “oiiotool -threads 1 -runstats >> in.dpx -o out.dpx” >> >> 1.8.17: consistently executes in 0.30 s (sometimes a little bit less) >> 2.0.10: consistently executes in 1.0+ s (sometimes a little bit less) >> >> I haven’t been able to successfully get Python bindings to work yet because >> of some DLL import issues. (lovely DLLs) I’ll keep trying but I’m not sure >> which third party lib is the culprit so this might take a little while to >> figure out. >> I’ll ran my benchmark script when I can fix my build. >> _______________________________________________ >> Oiio-dev mailing list >> [email protected] <mailto:[email protected]> >> http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org >> <http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org> > -- > Larry Gritz > [email protected] <mailto:[email protected]> > > > > > _______________________________________________ > Oiio-dev mailing list > [email protected] > http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org -- Larry Gritz [email protected]
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