[FFmpeg-devel] Added require fallback for libmfx in the case that pkg-config cannot find libmfx

[Aaron Levinson]

On 5/5/2017 12:57 AM, Clément Bœsch wrote:
> On Fri, May 05, 2017 at 12:54:12AM -0700, Aaron Levinson wrote:
> [...]
>>> Back to your issue: you should fix the .pc in the upstream project, this
>>> is the correct fix.
>>
>> The "upstream project" in this case is the Intel Media SDK.  This is not an
>> open source project, and developers get it through Intel in the form of an
>> installation package on Windows.  So, there is no opportunity to "fix the
>> .pc"--there isn't one, nor is there any way to contribute one.
>
> OK so we have a common configure flag for supporting two different
> projects with different authors, licensing, etc?
>
> Maybe we should have 2 configure flags? Add --enable-libmfxintel or
> whatever?

The licensing is the same--lu_zero's (Luca Barbato's) libmfx project 
just packages the files from the Intel Media SDK (or more likely Intel 
Media Server Studio).  And this means that there is effectively one 
author as well.  While the licensing for libmfx (really, mfx_dispatch) 
is suitable for open source projects, I don't think the same can be 
claimed for the Intel Media SDK or the Intel Media Server Studio as a 
whole, and it is technically necessary to install one of those to get 
the mfx_dispatch sources.  I really didn't want this to turn into 
another non-free discussion ala Blackmagic.  I'm fairly certain that 
Intel's intention is that the mfx_dispatch sources are suitable for use 
in open source projects, but it would be helpful if Intel offered the 
mfx_dispatch sources independent of either the Intel Media SDK or Intel 
Media Server Studio.

Nevertheless, it does seem reasonable to have another configure flag to 
enable the use of libmfx via Intel's official installers, which don't 
provide anything for pkg-config.  Even Intel Media Server Studio, which 
is available for Linux, doesn't provide anything for pkg-config, and the 
instructions at 
http://www.intel.com/content/dam/www/public/us/en/documents/white-papers/quicksync-video-ffmpeg-install-valid.pdf 
describe a process for manually creating a libmfx.pc file in order to be 
able to build ffmpeg with Intel Media Server Studio.  I'll scrap this 
patch and work on a different patch that uses this approach.

Aaron