Using ffmpeg (libavcodec and libavformat) libraries...

_UnPrEdictAbLe_ · 07-27-2005, 07:03 AM

Hi,
I am working on some code which uses ffmpeg sourcecode. To compile it I use

Code:

g++ -g -O3 -Wall -g -I. -I./ -I./libavcodec -I./libavformat -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_GNU_SOURCE -c -o output_example.o output_example.cpp

g++ -Wl,--warn-common -rdynamic -g  -o output_example output_example.o -L./libavformat -lavformat -L./libavcodec -lavcodec -lm -lz -ldl robovision.o -ljpeg

I seriously do not know what it all means, but I am compiling my code(robovision.cpp,robovision.h and output_example.cpp) by putting it in the directory containing the sourcecode of ffmpeg-0.4.8. This means that inspite of my code being only 3 files, I have to mess up with a thousand more files...

The only place where ffmpeg is used is in output_example.cpp

Code:

#include <stdlib.h>
#include <stdio.h>
#include <iostream>
#include <fstream>
#include <math.h>
#include <string.h>
#include <time.h>
#ifndef M_PI
#define M_PI 3.1415926535897931
#endif

#include "libavformat/avformat.h"
#include "robovision.h"

/* 10 FPS */
#define STREAM_FRAME_RATE 10  
/*..... and so on.......*/

When I checked my system for ffmpeg.. it had ffmpeg-0.4.9-0.2.20050427.2.fc4 installed already. Can I do something to use the library installed in the system and thus reduce the mess in which I am. Please reply asap.

Regards,
Unpredictable.

acid_kewpie · 07-27-2005, 07:13 AM

installing in the same directory as the FFMPEG source??

erm.. why?

you need to have the matching -devel rpm for any package against which you need to compile software. you won't need the source code. just install it, compile your software in a dedicated directory somewhere, and as long as you've installed the necessary packages and your include parameters for gcc are correct it will find the ffmpeg headers just fine.

_UnPrEdictAbLe_ · 07-27-2005, 07:49 AM

Thanks for the reply acid. I figured out that myself just now. I installed ffmpeg-devel.

And now I use these commands to compile...
g++ -g -O3 -Wall -g -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_GNU_SOURCE -c -o robovision.o robovision.cpp
g++ -g -O3 -Wall -g -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_GNU_SOURCE -c -o output_example.o output_example.cpp

g++ -Wl,--warn-common -rdynamic -g -o output_example output_example.o -lavformat -lavcodec -lavcodec -lm -lz -ldl robovision.o -ljpeg

and #include <ffmpeg/avformat.h> in the output_example.cpp file and it works just fine. I really don't know how to make a makefile. If you could make a makefile out of these random commands so that it compiles only when required and only the components which are changed, then please do it for me.

Regards,
Anurag.