[FFmpeg-devel] [PATCH] configure libvpx check version of decoder only

Reimar Döffinger Reimar.Doeffinger
Sat Jul 31 17:53:40 CEST 2010


On Fri, Jul 30, 2010 at 06:00:58PM -0700, Frank Barchard wrote:
> On Thu, Jul 29, 2010 at 12:42 AM, Reimar D?ffinger <Reimar.Doeffinger at gmx.de
> > wrote:
> 
> > On Thu, Jul 29, 2010 at 12:28:44AM -0700, Frank Barchard wrote:
> > > This patch allows ffmpeg to configure and build against libvpx when it
> > > just contains the decoder.
> > > libvpx version checked, but only for the decoder.
> >
> > Uh, and then compilation just fails?
> 
> 
> It builds correctly if you configure both libvpx and ffmpeg for decode only:
> Configure libvpx with --enable-vp8-decoder and do a local 'make install'
> Configure ffmpeg with --enable-decoder=libvpx and it only uses libvpxdec.c
> decoder functions.
> The ffmpeg build produces a smaller avcodec-52.dll that decodes webm files
> correctly.

So in other words, yes, it just fails at compile time unless you
manually work around it by explicitly disabling the encoder.
That definitely is not at all how configure is supposed to work.

> > Also with the native VP8 decoder I don't see a real point in
> > supporting this configuration - if it was as trivial as this patch
> > maybe, but it isn't.
> 
> For now this configuration has some useful features.
> Such as the NEON support, that Jason points out.

Which is why the libvpx decoder support is still there at all,
but personally I wouldn't consider it sufficient to make an extra
effort to support a decode-only libvpx.
I am not the configure/build system maintainer though, but I'm sure
he'll at least expect a working version, too.



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