[Buildroot] [PATCH] ffmpeg: fix static linking build failure when using libavutil

[Giulio Benetti]

Hello,

Il 12/10/2018 21:50, Thomas Petazzoni ha scritto:
> Hello,
> 
> On Fri, 12 Oct 2018 19:38:14 +0200, Giulio Benetti wrote:
> 
>>>>>> Indeed, when we're dynamic linking, there is no need to link consumers
>>>>>> of libavutil with libdrm. It is only when we're statically linking that
>>>>>> it should be done. And that's exactly what Libs vs. Libs.private is for.
>>>>>
>>>>> You've explained me it very well, but by now FFmpeg upstreamed my patch:
>>>>> https://git.ffmpeg.org/gitweb/ffmpeg.git/commit/c50dc77ac708e98d02da7c422a6b9cbf9f565aa5
>>>>>
>>>>> So, do I rework and resubmit to them or can I re-create a patch for BR
>>>>> with what you've pointed me above?
>> I've missed one thing to ask you about ffmpeg:
>> Can I still use this hack:
>> https://git.ffmpeg.org/gitweb/ffmpeg.git/blobdiff/bc2301429e9c779237e43acf913331af018211f2..c50dc77ac708e98d02da7c422a6b9cbf9f565aa5:/configure
>>
>> to obtain if -ldrm is used and then add it to Libs.private like this:
>> Libs.private: -ldrm
>>
>> as you've pointed me.
>>
>> Or there is something that makes it simpler and better?
> 
> I'm not sure what "hack" you're talking about here. My only point it is
> only needed to link "indirect" libraries when static linking, and
> therefore such "indirect" libraries should be listed in Libs.private
> and not Libs in pkg-config files.

Ok, sorry but I don't have much experience with Autotools and 
dynamic/static linking, I'm learning here "on the field".
I will try to submit a patch producing what you've described in the best 
way I can.

Best regards
-- 
Giulio Benetti
CTO

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