[Libav-user] Compiling ffmpeg with pthread support mscv toolchain

Leonardo Nahra leonardonahra at gmail.com
Mon Sep 12 21:04:50 EEST 2016


On Fri, Sep 9, 2016 at 12:46 PM, Carl Eugen Hoyos <ceffmpeg at gmail.com>
wrote:

> 2016-09-09 16:08 GMT+02:00 Leonardo Nahra <leonardonahra at gmail.com>:
> > On Fri, Sep 9, 2016 at 6:59 AM, Carl Eugen Hoyos <ceffmpeg at gmail.com>
> wrote:
>
> >> >  --enable-pthreads
> >> >  --extra-libs=pthreadVC2.lib
> >>
> >> What does threading support show if you omit these two lines?
> >
> > It shows "threading support w32threads"
>
> Why is this bad?
>
> You will have to post the relevant lines from config.log if
> you need pthread support.


I'm not sure what the relevant lines of the config.log would be, but I
found some lines that may be related to this problem:

check_func posix_memalign
check_ld cc
check_cc
BEGIN ./ffconf.SDAJxYXo.c
    1 extern int posix_memalign();
    2 int main(void){ posix_memalign(); }
END ./ffconf.SDAJxYXo.c
c99wrap cl -D_ISOC99_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE
-Dstrtod=avpriv_strtod -Dsnprintf=avpriv_snprintf
-D_snprintf=avpriv_snprintf -Dvsnprintf=avpriv_vsnprintf
-D_WIN32_WINNT=0x0502 -nologo -D_USE_MATH_DEFINES -D_CRT_SECURE_NO_WARNINGS
-D_CRT_NONSTDC_NO_WARNINGS -I/home/%username%/ffmpeg/include -c
-Fo./ffconf.UUlikmky.o ./ffconf.SDAJxYXo.c
ffconf.UUlikmky.o_converted.c
./compat/windows/mslink -L/home/%username%/ffmpeg/lib -nologo
-LARGEADDRESSAWARE -out:./ffconf.omVGyQVw.exe ./ffconf.UUlikmky.o
pthreadVC2.lib
LINK : warning LNK4044: unrecognized option
'/LC:/c99/home/%username%/ffmpeg/lib'; ignored
ffconf.UUlikmky.o : error LNK2019: unresolved external symbol
_posix_memalign referenced in function _main
./ffconf.omVGyQVw.exe : fatal error LNK1120: 1 unresolved externals

...

check_func pthread_create -pthread
check_ld cc -pthread
check_cc -pthread
BEGIN ./ffconf.SDAJxYXo.c
    1 extern int pthread_create();
    2 int main(void){ pthread_create(); }
END ./ffconf.SDAJxYXo.c
c99wrap cl -D_ISOC99_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE
-Dstrtod=avpriv_strtod -Dsnprintf=avpriv_snprintf
-D_snprintf=avpriv_snprintf -Dvsnprintf=avpriv_vsnprintf
-D_WIN32_WINNT=0x0502 -nologo -D_USE_MATH_DEFINES -D_CRT_SECURE_NO_WARNINGS
-D_CRT_NONSTDC_NO_WARNINGS -I/home/%username%/ffmpeg/include -pthread -c
-Fo./ffconf.UUlikmky.o ./ffconf.SDAJxYXo.c
cl : Command line warning D9002 : ignoring unknown option '-pthread'
ffconf.UUlikmky.o_converted.c
./compat/windows/mslink -L/home/%username%/ffmpeg/lib -nologo
-LARGEADDRESSAWARE -pthread -out:./ffconf.omVGyQVw.exe ./ffconf.UUlikmky.o
psapi.lib advapi32.lib shell32.lib pthreadVC2.lib
LINK : warning LNK4044: unrecognized option
'/LC:/c99/home/%username%/ffmpeg/lib'; ignored
LINK : warning LNK4044: unrecognized option '/pthread'; ignored

this error is repeated with several other functions that may be related to
pthread.

I'm trying to compile ffmpeg with pthread support because when I try to run
a project (that used an older ffmpeg version) with the version that I
compiled, I get the following error right after calling the function
avio_open():

[udp @ ...] 'circular_buffer_size' option was set but it is not supported
on this build (pthread support is required)

Than you, Nahra
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