[Ffmpeg-devel] [bug] raw.c link failure on ff_ac3_parse_header
Tue Apr 10 10:53:18 CEST 2007
Diego Biurrun <diego at biurrun.de> writes:
> On Mon, Apr 09, 2007 at 09:42:07PM +0100, M?ns Rullg?rd wrote:
>> Diego Biurrun <diego at biurrun.de> writes:
>> > On Thu, Mar 22, 2007 at 10:35:40AM +0200, Uoti Urpala wrote:
>> >> On Thu, 2007-03-22 at 09:21 +0100, Diego Biurrun wrote:
>> >> > On Wed, Mar 21, 2007 at 11:31:34PM -0500, Justin Ruggles wrote:
>> >> > > It seems to me that putting ac3.o in the OBJS list in the libavcodec
>> >> > > Makefile would solve this. Would this be an ok thing to do?
>> >> >
>> >> > No. The report remains incomplete and the problem unreproducible.
>> >> The problem seems clear: libavformat/raw.c unconditionally compiles a
>> >> call to ff_ac3_parse_header, but that function itself is not compiled
>> >> unconditionally.
>> > Attached is a patch that fixes the issue and makes ff_ac3_parse_header
>> > conditional to CONFIG_AC3_PARSER, which I believe is the correct
>> > solution. Is it necessary to #ifdef ff_ac3_parse header in ac3.h as
>> > well?
>> If it compiles correctly in both cases, no.
> It compiles fine. It was more of a general style question. My question
> was whether it should be indicated with an #ifdef in the header file
> that this function is conditionally compiled.
I generally use the simple rule that code with no effect shouldn't
exist. This applies equally to preprocessor directives and actual
>> > --- libavformat/allformats.c (revision 8688)
>> > +++ libavformat/allformats.c (working copy)
>> > @@ -45,7 +45,8 @@
>> > avcodec_register_all();
>> > REGISTER_DEMUXER (AAC, aac);
>> > - REGISTER_MUXDEMUX(AC3, ac3);
>> > + if (ENABLE_AC3_PARSER) REGISTER_DEMUXER (AC3, ac3);
>> > + REGISTER_MUXER (AC3, ac3);
>> You could make AC3_DEMUXER depend on AC3_PARSER in configure instead.
>> That might be cleaner.
> Yes, I might do that.
> I'm thinking that it might be cleaner to move ff_ac3_parse_header out of
> ac3.c and into parser.c where the other parse functions are. This would
> save some #ifdefs in ac3.c.
I'm undecided on the location of these things. In a way I like to
keep everything relating to a particular codec together, especially
when the decoder uses the same functions. OTOH keeping the parser
code in one place has its virtues.
mans at mansr.com
More information about the ffmpeg-devel