[MPlayer-dev-eng] c++ and libmpcodec

[Miroslav Shaltev]

hi @ all,

i hope i post my quesion to the right place, if not so, please sorry (and ban 
me to the right list -> tnx).

the problem:

i try to add a decoderlib to libmpcodecs. however the decoderlib is written in 
c++ (?!) , so i can not simply include the headers and rest in a simple 
vd_mylib.c file. therefor i add vd_mylib.cpp , change the Makefile. Running 
make in libmpcodecs is ok, but make ontop ends with

g++ -I../libvo -I../../libvo -I/usr/X11R6/include -fno-PIC -O4 -march=athlon-4 
-mcpu=athlon-4 -pipe -ffast-math -fomit-frame-pointer  -I. 
-I/usr/include/freetype2   -I/usr/include/SDL  -I/usr/X11R6/include       -o 
mplayer mplayer.o mp_msg.o cpudetect.o codec-cfg.o spudec.o playtree.o 
playtreeparser.o asxparser.o vobsub.o subreader.o sub_cc.o find_sub.o 
m_config.o m_option.o parser-cfg.o m_struct.o edl.o unrarlib.o mixer.o 
parser-mpcmd.o subopt-helper.o libvo/libvo.a libao2/libao2.a  
vidix/libvidix.a  libmpcodecs/libmpcodecs.a loader/libloader.a 
loader/dshow/libDS_Filter.a loader/dmo/libDMO_Filter.a libaf/libaf.a 
libmpdemux/libmpdemux.a input/libinput.a postproc/libswscale.a 
osdep/libosdep.a -Llibmpdvdkit2 -lmpdvdkit libavcodec/libavcodec.a   -lmad   
-lstdc++ -llzo -ldivxdecore   -lxvidcore -lm  -lpng -lz -lz -ljpeg -lasound 
-ldl -lpthread   -lfreetype -lz  -lcdda_interface -lcdda_paranoia -lnsl  
-lgif  -lsmbclient  -lfontconfig    libfaad2/libfaad2.a  mp3lib/libMP3.a 
liba52/liba52.a libmpeg2/libmpeg2.a tremor/libvorbisidec.a  -laa -lGL 
-lXxf86dga -lXv  -lXxf86vm -lXinerama -L/usr/X11R6/lib -lXext -lX11 -lnsl 
-lnsl -L/usr/lib -Wl,-rpath,/usr/lib -lSDL -lpthread    -lvgagl -lvga -lm   
-L/usr/kde/3.4/lib -ldl -lartsc -lpthread -lgmodule-2.0 -ldl -lgthread-2.0 
-lglib-2.0 -L/usr/lib -lesd -laudiofile -lm -lasound -lbio2jack -ljack          
-lpthread -ldl -rdynamic   -lm
libmpcodecs/libmpcodecs.a(vd_mylib.o)(.text+0x23): In function `init':
: undefined reference to `showmsg'
collect2: ld returned 1 exit status
make: *** [mplayer] Error 1

showmsg  is just a test funktion in my cpp file i try to "see" from 
vd_mylib.c. i think the problem is in the way c++ handles function naming, or 
so, there are in general visability problems between c / c++. in a simple two 
file project, i can use c++ funktions in c program, the same syntax do not 
works in mplayer, and i have really no idea why. for any suggestions many 
many tnx.

regards,
miroslav

p.s. some code

in 
vd_mylib.c

#include "vd_mylib_link.h"

static int init(sh_video_t *sh){
	showmsg("I told you, you will see how stupied c++ can be!!!");
	return mpcodecs_config_vo(sh,sh->disp_w,sh->disp_h,IMGFMT_YV12);
}

in
vd_mylib_link.h

#ifdef __cplusplus
 extern "C" {
 #endif

int showmsg(const char *fStr);

#ifdef __cplusplus
 }
 #endif

in
vd_mylib.cpp
int showmsg(const char *fStr){
	std::cout << fStr << std::endl;
	return 0;	
}


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