[FFmpeg-devel] [PATCH] libavcodec/makefile: prevent from installing disabled headers.

[Reimar Döffinger]

On 19.10.2014, at 20:53, Matt Oliver <protogonoi at gmail.com> wrote:
> This stops headers based on disabled functionality from being installed.
> Things like VDA and VDPAU dont work on windows etc. So any attempt to use
> these headers will result in compilation errors so best not to install them
> to avoid confusion. Also no point having a header for functionality that
> wasnt built into the libs.
> So exclude headers if they cannot be used.

I don't see any real advantage whatsoever for this, the few kB saved are not of much advantage, especially as they are only saved on developer systems.
Also, VDPAU as an API can most certainly work on Windows if one wanted it to.
In fact, it will probably compile just fine at the least under cygwin (even if there is not backend implementation).
Lastly, if you remove a header it will also break programs that try to use runtime detection e.g. via dlopen or other mechanisms to figure out if the feature exists or not, and they suddenly have to check at compile time instead.
The last part IMHO makes that this is in fact just wrong to do.