[FFmpeg-cvslog] r15151 - in trunk: configure libavcodec/Makefile

[Aurelien Jacobs]

On Wed, 3 Sep 2008 01:29:15 +0200
Diego Biurrun <diego at biurrun.de> wrote:

> On Wed, Sep 03, 2008 at 01:21:13AM +0200, Aurelien Jacobs wrote:
> > On Wed, 3 Sep 2008 00:57:57 +0200
> > Diego Biurrun <diego at biurrun.de> wrote:
> > 
> > > On Wed, Sep 03, 2008 at 12:45:18AM +0200, Aurelien Jacobs wrote:
> > > > On Wed, 3 Sep 2008 00:27:56 +0200
> > > > Diego Biurrun <diego at biurrun.de> wrote:
> > > > 
> > > > > On Tue, Sep 02, 2008 at 10:54:53PM +0200, Aurelien Jacobs wrote:
> > > > > > On Tue, 2 Sep 2008 19:06:29 +0200
> > > > > > Diego Biurrun <diego at biurrun.de> wrote:
> > > > > > 
> > > > > > > On Tue, Sep 02, 2008 at 06:04:27AM +0200, jbr wrote:
> > > > > > > > 
> > > > > > > > Log:
> > > > > > > > add a separate line in Makefile for E-AC-3 decoder and only compile it when
> > > > > > > > GPL is enabled. fixes building without GPL or with liba52.
> > > > > > > > 
> > > > > > > > --- trunk/configure	(original)
> > > > > > > > +++ trunk/configure	Tue Sep  2 06:04:26 2008
> > > > > > > > @@ -848,6 +848,7 @@ byteswap_h_deps="!armv4l"
> > > > > > > >  # decoders / encoders
> > > > > > > >  ac3_decoder_deps="gpl !liba52"
> > > > > > > >  dxa_decoder_deps="zlib"
> > > > > > > > +eac3_decoder_deps="gpl"
> > > > > > > > 
> > > > > > > > --- trunk/libavcodec/Makefile	(original)
> > > > > > > > +++ trunk/libavcodec/Makefile	Tue Sep  2 06:04:26 2008
> > > > > > > > @@ -63,6 +63,7 @@ OBJS-$(CONFIG_DVDSUB_ENCODER)          +
> > > > > > > >  OBJS-$(CONFIG_DXA_DECODER)             += dxa.o
> > > > > > > > +OBJS-$(CONFIG_EAC3_DECODER)            += eac3dec.o ac3dec.o ac3tab.o ac3dec_data.o ac3.o mdct.o fft.o
> > > > > > > 
> > > > > > > I think it's easier to just make the E-AC-3 decoder depend on the AC-3
> > > > > > > decoder.
> > > > > > 
> > > > > > ./configure --enable-gpl --enable-decoder=eac3 --disable-decoder=ac3
> > > > > > works fine, and I see no valid reason to prevent it
> > > > > 
> > > > > Small wonder - these flags have no effect at all.
> > > > 
> > > > They have an effect !
> > > > With this configure line the ac3_decoder won't be registered with
> > > > register_avcodec().
> > > > And thus CODEC_ID_AC3 won't be handled by any decoder.
> > > 
> > > Let me rephrase: They are pointless since the code is compiled, but the
> > > codec is not registered.  What for?
> > 
> > There isn't much reason to do this on purpose, except for controling
> > precisely which CODEC_ID you want that lavc accept decoding or not.
> > But this is not the point. Users don't know about all of that.
> > And some users will triger this situation, especially by disabling
> > everything and only enabling eac3 decoder. And I can't imagine
> > any valid argument why we should fail such a request. Is there any ?
> 
> I think that users would expect this to eliminate some code.

And this will actually eliminate *lots* of code when users do
--disable-decoders --enable-decoder=eac3
Here the user don't care whether all the ac3 decoding code is
still present or note. He just want to enable eac3 and elminate
as much code as possible.

> > Oh, and you propose to make eac3 depends on ac3, but why wouldn't
> > it be the opposit ? Why placing one of them in a favored situation ?
> > They should IMO be treated in a stricly equal way.
> 
> No, my proposition is to just have an AC-3 decoder and mention that it
> supports E-AC-3 as well.

That's the way it was when Justin commited the last part of the eac3
decoder. But This didn't allowed proper muxing of eac3 in various
containers.

Aurel