A few more questions:
How are you reading the files? I know that you saw a fix with implementing a
DPXInput::read_image(), but are you indeed reading directly through an API call
to ImageInput::read_image()? Or using an ImageBuf?
From C++ or from Python?
Do you see the slowdown if you are reading just one DPX file at a time, or do
you only see it if you are reading a bunch of files simultaneously, as appeared
in the demo video?
-- lg
> On Sep 3, 2019, at 11:09 PM, Larry Gritz <[email protected]> wrote:
>
> I still don't quite understand what would have caused the performance
> degradation, so I'm going to compare the code to try to understand what
> changed.
>
> Is there anything characteristic about the DPX files? Just ordinary RGB?
> Anything unusual about them, especially high resolution, or other attributes?
> Or did you see orders of magnitude slowdown with every file you tried? Are
> you Windows only or did you get a chance to see if a slowdown was apparent on
> Linux or OSX as well? Trying to understand what happened, as DPX is pretty
> widely used in studios but nobody had previously noticed this.
>
> -- lg
>
>
>> On Sep 3, 2019, at 10:37 PM, Renaud Talon <[email protected]
>> <mailto:[email protected]>> wrote:
>>
>> This use to work fine for me on 1.8.5 and previous. I honestly didn’t update
>> OIIO before the first(ish) release of OIIO 2.0 and that’s when I started
>> running into the performance issues with DPXs.
>>
>> At the time I was compiling with a certain set of thrid party libraries and
>> Visual Studio 2015. Since then I re-compiled all my dependencies for Visual
>> Studio 2017 and made a new attempt at compiling oiio 2.0 (in this case
>> 2.0.10) but I ran into the same performance issue.
>>
>> My initial test code was using the “read_scanline()” method instead of
>> “read_image()” and Michael’s patch only fixes the read_image() method of
>> course so the problem remains with “read_scanline()”.
>>
>> I did compare the dpx plugin code between 1.8.5 and 2.0.10 and noticed that
>> there were quite a few changes that were made but my C++ skills are not
>> advanced enough for me to figure out what could cause this behavior.
>>
>> I created a PR but this is more to help keep track of the issue than a
>> request to merge this code in as I don’t think this is a proper “long-term”
>> fix.
>>
>> Thanks again,
>>
>> Renaud
>>
>> From: Larry Gritz <mailto:[email protected]>
>> Sent: Tuesday, September 3, 2019 5:37 PM
>> To: OpenImageIO developers <mailto:[email protected]>
>> Subject: Re: [Oiio-dev] OIIO 2.x extremely slow DPX load time
>>
>> Definitely. Can you prepare a real PR with the patch that seems to work?
>>
>> I'll do some digging to try to figure out what broke. Did it used to be like
>> this and we broke something?
>>
>>
>>
>>
>> On Sep 3, 2019, at 5:32 PM, Renaud Talon <[email protected]
>> <mailto:[email protected]>> wrote:
>>
>> Hi Michael,
>>
>> your patch absolutely works ! My benchmark goes from 60s+ to 700ms !!!
>>
>> I was getting corrupted images with my test code at first because I wasn't
>> passing the image spec.format to the "read_image()" method. (which worked
>> fine with OIIO 1.8.5 but is clearly needed to use the DPXInput::read_image
>> patch you provided)
>>
>> I changed :
>> pixels = srcFile.read_image()
>>
>> to:
>> pixels = srcFile.read_image(spec.format)
>>
>> and it worked like a charm.
>>
>> Larry, if you're reading this. Could we get Michael's patch or a similar fix
>> merged into OIIO code please ?
>> Thanks,
>>
>> Renaud
>> _______________________________________________
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>>
>> --
>> Larry Gritz
>> [email protected] <mailto:[email protected]>
>>
>>
>>
>>
>>
>>
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>> <http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org>
> --
> Larry Gritz
> [email protected] <mailto:[email protected]>
>
>
>
>
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--
Larry Gritz
[email protected]
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