Re: pkg/48116 (multimedia/ffmpeg / ffplay do not build)

[Stefan Schaeckeler <schaecsn%gmx.net@localhost>]

The following reply was made to PR pkg/48116; it has been noted by GNATS.

From: Stefan Schaeckeler <schaecsn%gmx.net@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: pkg/48116 (multimedia/ffmpeg / ffplay do not build)
Date: Sun,  1 Sep 2013 13:13:39 -0700 (PDT)

 >  >  The second part of my bug report, the linking issue of ffplay (perhaps 
 > only on Linux?), is not yet addressed.
 >  
 >  Separate bug reports for separate problems makes lives easier :)
 
 I can't disagree, but here we have to deal with a package that was 
artificially split into two packages by the pkgsrc team. So problems and 
solutions are interleaved. I looked into the ffplay linker problem:
 
 
 1. Need to know:
 
 With configure option --disable-asm, the library libavcodec is solely build 
from sources in ./ffmpeg-1.2.1/libavcodec/.
 
 Without option --disable-asm, most files are taken from 
./ffmpeg-1.2.1/libavcodec/ but others are taken from 
./ffmpeg-1.2.1/libavcodec/x86/.
 
 
 
 2. At least on my machine:
 
 configure option --disble-asm must be passed to gcc 4.3.3. Gcc 4.5 does not 
need this option (at least not with CFLAGS+= -O2 -march=pentium4 -pipe)
 
 
 
 3. my linker issue with the current pkgsrc Makefile in multimedia/ffplay is 
for gcc 4.3.3 with configure option --disable-asm (without --disable-asm,  I 
run into the 'can't find a register' issue posted above):
 
 libavcodec/libavcodec.so: undefined reference to `ff_mpeg_draw_horiz_band'
 libavcodec/libavcodec.so: undefined reference to `ff_h264_draw_horiz_band'
 
 
 These definitions are in
 
 ./ffmpeg-1.2.1/libavcodec/mpegvideo.c:void 
ff_mpeg_draw_horiz_band(MpegEncContext *s, int y, int h)
 
 ./ffmpeg-1.2.1/libavcodec/h264.c:void ff_h264_draw_horiz_band(H264Context *h, 
int y, int height)
 
 
 The Makefile in multimedia/ffmpeg does not trigger the compilation of these 
two .c files. Experimenting showed that this is because configure option 
--disable-decoders is passed in multimedia/ffplay/Makefile.
 
 When configuring without option --disable-asm, alternative code is taken from 
ffmpeg-1.2.1/libavcodec/x86/ that does not refer to these definitions.
 
 
 
 4. Fix. I see several ways to proceed:
 
 A. compile everything with gcc 4.5
 
  Add GCC_REQD+= 4.5 to ffmpeg/Makefile.common. This makes sure that configure 
option --disable-asm is not chosen.
 
 Or
 
 B. Move the gcc version checks from ffmpeg/Makefile to ffmpeg/Makefile.common. 
Make sure these checks pass --disable-asm to gcc 4.3.3. Then, also comment out 
CONFIGURE_ARGS+= --disable-decoders in ffplay/Makefile for this version of gcc 
to make sure mpegvideo.c and h264.c are compiled into libavcodec/libavcodec.so.