Experimental Physics and
Industrial Control System

Andrew Johnson <[email protected]> · Wed, 13 Nov 2013 17:32:10 -0600

Hi Murali,

On 11/13/2013 05:17 PM, Shankar, Murali wrote:

My question is about how to add avcodec to the product (executable)
correctly? Should I use |USR_LIBS| or |PROD_LIBS| or something else? All
of these seem to give me various make/linker errors. I’d like to stay
within the EPICS build system to solve the problem of

1)Include an external library in your install package using LIB_INSTALLS

2)Include it in your product using xyz…

Do you actually need to install a copy that library, or are you just

doing that to try and get it to work?

To link a program with an external library you add the library name to

the _LIBS variable as usual, then you just tell the build system where

that library can be found by setting its *_DIR variable. In your case I

think you just need these lines in the Makefile that is building the

executable:

avcodec_DIR = $(PACKAGE_SITE_TOP)/ffmpeg/$(FFMPEG_MODULE_VERSION)/lib
xxx_LIBS += avcodec
  to link it into just the program 'xxx', or
PROD_LIBS += avcodec

 if you're building multiple programs and want this linked into all of

them.

If that doesn't work my memory may be slightly off, but I think it's right.

- Andrew
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Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System