FFmpeg似乎是版本冲突

Question

I am using git version of ffmpeg( renewed after old version succesful using) , when i try to compile my project i get

 /usr/local/lib/libavcodec.a(opusdec.o): In function `opus_decode_subpacket':
/home/user/projects/ffmpleglast/ffmpeg/libavcodec/opusdec.c:376: undefined reference to `swr_is_initialized'
/usr/local/lib/libavcodec.a(opusdec.o): In function `opus_decode_frame':
/home/user/projects/ffmpleglast/ffmpeg/libavcodec/opusdec.c:222: undefined reference to `swr_is_initialized'
/usr/local/lib/libavcodec.a(opusdec.o): In function `opus_init_resample':
/home/user/projects/ffmpleglast/ffmpeg/libavcodec/opusdec.c:163: undefined reference to `swr_init'
/home/user/projects/ffmpleglast/ffmpeg/libavcodec/opusdec.c:169: undefined reference to `swr_convert'
/usr/local/lib/libavcodec.a(opusdec.o): In function `opus_decode_frame':
/home/user/projects/ffmpleglast/ffmpeg/libavcodec/opusdec.c:236: undefined reference to `swr_convert'
/usr/local/lib/libavcodec.a(opusdec.o): In function `opus_flush_resample':
/home/user/projects/ffmpleglast/ffmpeg/libavcodec/opusdec.c:117: undefined reference to `swr_convert'
/usr/local/lib/libavcodec.a(opusdec.o): In function `opus_decode_subpacket':
/home/user/projects/ffmpleglast/ffmpeg/libavcodec/opusdec.c:408: undefined reference to `swr_close'
/usr/local/lib/libavcodec.a(opusdec.o): In function `opus_decode_flush':
/home/user/projects/ffmpleglast/ffmpeg/libavcodec/opusdec.c:557: undefined reference to `swr_close'
/usr/local/lib/libavcodec.a(opusdec.o): In function `opus_decode_close':
/home/user/projects/ffmpleglast/ffmpeg/libavcodec/opusdec.c:579: undefined reference to `swr_free'
/usr/local/lib/libavcodec.a(opusdec.o): In function `opus_decode_init':
/home/user/projects/ffmpleglast/ffmpeg/libavcodec/opusdec.c:629: undefined reference to `swr_alloc'

Seems to be version conflict? but how to delete wrong libs? they seem to be todays build.

ls -l /usr/local/lib
-rw-r--r-- 1 root root  136509684 may   29 14:47 libavcodec.a
-rw-r--r-- 1 root root    1853574 may   29 14:47 libavdevice.a
-rw-r--r-- 1 root root    9689456 may   29 14:47 libavfilter.a
-rw-r--r-- 1 root root   46282270 may   29 14:47 libavformat.a
-rw-r--r-- 1 root root    2092250 may   29 14:47 libavutil.a
-rw-r--r-- 1 root root      67942 may   12 11:29 libBasicUsageEnvironment.a
-rw-r--r-- 1 root root    2200164 apr.  10 10:11 libfftw3.a
-rwxr-xr-x 1 root root        872 apr.  10 10:11 libfftw3.la
-rw-r--r-- 1 root root      94188 may   12 11:29 libgroupsock.a
-rw-r--r-- 1 root root    2236084 may   12 11:29 libliveMedia.a
-rw-r--r-- 1 root root     546506 may   29 14:47 libswresample.a
-rw-r--r-- 1 root root    4813716 may   29 14:47 libswscale.a
-rw-r--r-- 1 root root      14588 may   12 11:29 libUsageEnvironment.a

Answer 1

I was getting these same kinds of errors when I was building a DLL which tried to pull in the ffmpeg DLLs.

I was missing the extern C statement around the ffmpeg include files :

extern "C"
{
#include "include\libavcodec\avcodec.h"
#include "include\libavformat\avformat.h"
#include "include\libavformat\avio.h"
#include "include\libswscale\swscale.h"
#include "include\libavutil\dict.h"
#include "include\libavutil\frame.h"
}

I also found that I needed to add the DLLs to the solution as dependencies or use the pragma statements to get it to include.

#pragma comment(lib, "..\\..\\..\\..\\contrib\\ffmpeg\\lib\\avformat.lib")
#pragma comment(lib, "..\\..\\..\\..\\contrib\\ffmpeg\\lib\\swscale.lib")
#pragma comment(lib, "..\\..\\..\\..\\contrib\\ffmpeg\\lib\\avutil.lib")

This was on windows and simply tells VS that the lib files specified detail the interfaces for DLLs in those same locations. You won't need that on linux as your -lavformat etc statements should cover it, but I suspect you might need the extern C part.

If its still not helping, maybe use verbose mode on the compile/link so you can see what's coming in from which locations.

Answer 2

You probably have also ffmpeg installed in system (in /usr/lib and /usr/include). Try to force include path with -I parameter (/usr/local/include) and library path with -L parameter (/usr/local/lib)