[FFmpeg-devel] [PATCH] Build scripts for WinRT

Simon Ferquel simon.ferquel at hotmail.fr
Wed Mar 25 09:52:41 CET 2015

>Please avoid top-posting on this list, thanks.

Sorry about that, I'm not really used to mailing lists

>On 24.03.2015, at 22:14, Simon Ferquel <simon.ferquel at hotmail.fr> wrote:
>> Axtually I don't know the meaning of enable thumb (it was in the ffmpef winrt compilation guide I followed).
>It generates smaller but somewhat slower code.
>IMHO unless instruction cache misses are a major issue (and even then) it doesn't make sense unless you optimize the code for size in general - which you clearly are not doing.
>Admittedly I do not know if anyone benchmarked it lately.
>Btw. do you know anything concerning armv8 support? Would be good to get testing of that early on as well (though of course not possible before official support, but with even the low-end making the transition on Android I would expect support for it soonish).

About enable-thumb, I'll give a try without (won't be able to test it on Windows, only have a phone arm device for now).
About armv8, there is actually a ./lib/arm64 in the windows 10 dev kit, but no public compiler for this atm. I'll keep you posted if I get any news on that (and would be glad to help target this architecture on Windows 10).

>> I also found some strange linking issues when building with disable-optimizations and / or as static libs. So, I'll resubmit the patch when these issues are fixed.

I'm giving some more tries, but I am close to having a fully functionnal build, with both win81/wp81 target and win10 preview. New patch soon.

>> ________________________________
>> De : Reimar Döffinger<mailto:Reimar.Doeffinger at gmx.de>
>> Envoyé : ‎24/‎03/‎2015 21:56
>> À : FFmpeg development discussions and patches<mailto:ffmpeg-devel at ffmpeg.org>
>> Objet : Re: [FFmpeg-devel] [PATCH] Build scripts for WinRT
>> On Tue, Mar 24, 2015 at 08:07:28AM +0000, Simon Ferquel wrote:
>>> I have needed libavformat/libavcodec for a drone piloting app project targetting (among others) the Windows modern platform (Win81 modern, Windows Phone, and Xbox one in a near future).
>>> To make it easier to generate static libs for all the combinations of os (win81/wp81), architecture (armv7, x86, x64) and C runtime configurations (debug CRT DLL or release CRT DLL), I wrote some bash scripts automating the setup of the environment variables needed for msvc, as well as the different flags to pass to the compiler to generate valid libraries for the modern windows app platform.
>>> This patch adds a bldwinrt folder with only bash scripts in it. They must be run in the msys2 environment and have been tested on Windows 8.1 64bit.
>> One question: You are aware that --enable-thumb is not the default on
>> purpose/for good reasons?
>> I wonder why you are using it.

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