[FFmpeg-devel] GSoC project (JPEG 2000)

[Aurelien Jacobs]

On Sun, Mar 27, 2011 at 02:04:23PM +0800, zhentan feng wrote:
> Hi
> 
> On Sun, Mar 27, 2011 at 1:46 PM, rukhsana afroz <rukhsana.afroz at gmail.com>wrote:
> 
> > On Sat, Mar 26, 2011 at 10:10 PM, Peter Ross <pross at xvid.org> wrote:
> >
> > >
> > > The FFmpeg build system forbids the use of global functions, without a
> > > previous
> > > prototype declaration. To fix this, you need to declare a
> > > 'ff_j2k_init_tier1_luts'
> > > prototype somewhere _or_ make the function static.
> > >
> > > From the gcc manpage:
> > >   -Wmissing-prototypes (C and Objective-C only)
> > >       Warn if a global function is defined without a previous prototype
> > > declaration.  This warning is issued even if
> > >       the definition itself provides a prototype.  The aim is to detect
> > > global functions that fail to be declared in
> > >       header files.
> > >
> >
> > Thanks Peter for your help. I made static this file in both declaration and
> > implementation. Now, I got rid of this problem. While linking jpeg 2000
> > with
> > ffmpeg, i got the following error:
> >
> > LD    ffmpeg_g
> >
> > /ubc/ece/home/vl/grads/rukhsana/gsoc11/ffmpeg/libavcodec/libavcodec.a(allcodecs.o):
> > In function `avcodec_register_all':
> > /ubc/ece/home/vl/grads/rukhsana/gsoc11/ffmpeg/libavcodec/allcodecs.c:128:
> > undefined reference to `ff_jpeg2000_decoder'
> > collect2: ld returned 1 exit status
> > make: *** [ffmpeg_g] Error 1
> >
> > If anybody could help getting rid of it, that would be great.
> >
> >
> This is link error.
> I think you should modify the libavcodec/Makefile like this:
> http://wiki.multimedia.cx/index.php?title=FFmpeg_codec_HOWTO#libavcodec.2FMakefile
> 
> <http://wiki.multimedia.cx/index.php?title=FFmpeg_codec_HOWTO#libavcodec.2FMakefile>

And rename the jpeg2000_decoder variable to ff_jpeg2000_decoder.
A ff_ prefix was added recently to all the decoders.

Aurel