[FFmpeg-devel] Patch for CUDA Scale Filter

[Alex Converse]

On Mon, Apr 17, 2017 at 2:51 PM, Timo Rothenpieler
<timo at rothenpieler.org> wrote:
>>> I'm generally in favor of adding CUDA based filtering, there's a lot of
>>> nice stuff that could be done that way.
>>>
>>> But there is one big issue with this approach:
>>>
>>> Having to run a .bat file prior to building isn't really nice, and not
>>> something I and some other people on IRC would like to see in ffmpeg.
>>>
>>> Instead, it would be nice if configure/make would learn how to handle
>>> .cu files, converting them straight to an object-file.
>>> My idea for this would be to teach the Makefiles about .cu files, and
>>> using a shell script as their compiler.
>>> That script can then call nvcc and include the ptx2c functionality, and
>>> additionally also calls the designated C compiler, so for the build
>>> system it converts .cu to .o.
>>>
>>> Also, due to these kind of filters having to include cuda.h, they need
>>> to be put behind --enable-nonfree in configure.
>>>
>>> That's what I have in mind so far. I didn't have time for a full review
>>> of the code yet, so can't say much about the filter itself.
>>
>>
>> I'm against. Building the "script" seems pretty terribly complicated,
>> and adding generated code is usually not what we do in this project.
>> This is probably done better with a d3d11 video scale filter, although
>> I'm not sure about the tradeoffs yet.
>
>
> That's exactly what I said though? Making configure/make generate the code
> at build time, so the generated code is not in the repo, only the actual .cu
> file.
>
> One problem with that is, that nvcc require cl.exe on Windows, it doesn't
> work with gcc. So that would limit it to MSVC builds on Windows, which is
> fine with me.
>

FWIW there are non-nvcc cuda compilers that run on Windows, like clang.
http://llvm.org/docs/CompileCudaWithLLVM.html