Thanks!
-jonathan
On Jun 17, 2013, at 4:22 PM, Larry Gritz wrote:
> I think I can make things easier for you on this front. Let me see what I
> can throw together. Stay tuned.
>
> In the mean time, I think you can probably make headway by compiling OIIO
> with a simple modification to src/libOpenImageIO/CMakeLists.txt -- just
> comment out line 123 that adds the two exr*.cpp files to the embedded list.
> Then it should find your plugin just fine (although it's not a "stock"
> libOpenImageIO at that point).
>
> -- lg
>
>
> On Jun 17, 2013, at 3:17 PM, Jonathan Egstad wrote:
>
>> Without getting into too much detail we've codec modifications to the
>> OpenEXR format that (hopefully soon!) will get rolled in to the standard
>> distribution. Until then we do need a customized plugin that has small
>> modifications to the codec enumerations and is linked against our OpenEXR
>> build.
>>
>> So it sounds like our near-term solution is to build oiio without embedded
>> plugins.
>>
>> However I do think it would be a worthwhile fix if it's trivial enough to do
>> as it would make plugin management more flexible.
>> If you don't want to change the API you could trap for a token in the search
>> path like '<builtins>:/tmp/oiio/plugins' that would determine where to
>> insert the embedded paths.
>>
>> -jonathan
>>
>> On Jun 17, 2013, at 2:06 PM, Larry Gritz wrote:
>>
>>> The idea of the plugins was to extend the set of supported file formats at
>>> runtime. An example would be if an application that uses OIIO wanted to
>>> support for GIF files (we don't, natively), they could write their own
>>> gif.imageio.so (or .dll) to extend support, rather than create a customized
>>> libOpenImageIO. Another example would be if there was a truly proprietary
>>> format (internal to one company, or one application), they could easily
>>> extend OIIO to support it just by writing that one DLL/DSO without
>>> cluttering the public distribution or without revealing to the world the
>>> details of their proprietary format.
>>>
>>> (Aside: In truth, although I always thought of the plugin mechanism as an
>>> important feature in an image library, it's not clear to me whether anyone
>>> at all uses the ability to extend format support at runtime. I started out
>>> with *all* formats supported via DSO/DLL's, even the ones that come with
>>> OIIO. It was user demand that led to format support being embedded in the
>>> library rather than DSO's. People overwhelmingly found the build and
>>> distribution simpler with one library rather than a dozen or more plugins.)
>>>
>>> I admit that I never really considered the case of somebody who wanted to
>>> *replace* an existing format module, rather than extend the set of file
>>> formats. So it's not surprising that the library always considers the
>>> built-in (embedded) implementations first, and only checks the DSO/DLL's if
>>> none of the embedded readers are able to open the file.
>>>
>>> If it's important to you, I think we could fix this pretty easily. I'm not
>>> sure I'd want it to be the default, but we could certainly make it an
>>> option to check for DSOs first, i.e., reverse the priority.
>>>
>>> Out of curiosity, what does your OpenEXR reader do that the standard one
>>> does not? Is a more productive route to propose an improvement to the
>>> built-in exr reader?
>>>
>>> -- lg
>>>
>>>
>>> On Jun 17, 2013, at 12:54 PM, Jonathan Egstad wrote:
>>>
>>>> Sorry if this has been answered before, I can't find a relevant mail.
>>>>
>>>> We've built oiio with embedded plugins and now we're attempting to
>>>> override the exr plugin with a customized one.
>>>> Unfortunately the plugin_searchpath string passed to ImpageInput::create()
>>>> does not appear to take precedence during the cataloging of available
>>>> plugins which means the embedded openexr plugin appears to always be found
>>>> first.
>>>>
>>>> Is this the expected behavior or am I doing something wrong?
>>>>
>>>> The custom exr plugin is handicapped so the plugin's open() method will
>>>> produce an assert error, but no assert is occurring so I'm assuming the
>>>> embedded openexr plugin is getting called instead.
>>>>
>>>> From my reading of imageioplugin.cpp the catalog_all_plugins() method
>>>> first calls catalog_builtin_plugins() before the searchpath string is
>>>> being parsed (I haven't yet built oiio with debug prints to see what's
>>>> going on in there, but that was going to be my next step.)
>>>>
>>>>
>>>> Thanks for any help,
>>>>
>>>> -jonathan
>>>>
>>>>
>>>> #include <OpenImageIO/imageio.h>
>>>>
>>>> using namespace OIIO_NAMESPACE;
>>>>
>>>> const char* plugin_searchpath = "/tmp/oiio/plugins";
>>>> const char* read_path = "/tmp/oiio/plugins/test.exr";
>>>>
>>>> int main(int argc, char* argv[]) {
>>>> ImageSpec spec;
>>>> ImageInput* reader = ImageInput::create(read_path, plugin_searchpath);
>>>> if (!reader) return 1;
>>>> if (!reader->open(read_path, spec)) {
>>>> std::cerr << "Unable to open file '" << read_path << "'" << std::endl;
>>>> return 1;
>>>> }
>>>>
>>>> std::cout << spec.width << "x" << spec.height << std::endl;
>>>>
>>>> return 0;
>>>> }
>>>>
>>>> _______________________________________________
>>>> Oiio-dev mailing list
>>>> [email protected]
>>>> http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org
>>>
>>> --
>>> Larry Gritz
>>> [email protected]
>>>
>>>
>>> _______________________________________________
>>> Oiio-dev mailing list
>>> [email protected]
>>> http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org
>>
>> _______________________________________________
>> Oiio-dev mailing list
>> [email protected]
>> http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org
>
> --
> Larry Gritz
> [email protected]
>
>
> _______________________________________________
> Oiio-dev mailing list
> [email protected]
> http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org
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