Build Tips

In addition to these tips, there is a build scripts page.

Help, I am stuck!

First of all, see the output of ./configure –help.

Secondly, if you are having a problem with a module besides core or avformat, then disable that module to get something working and perhaps come back to it later if you feel you really need it by adding –disable-<module> to the configure command, e.g., ./configure –disable-sox ….

If you are having problems with the avformat (FFmpeg) module, then see below.

Apple Mac OS X

I am using 10.6 (Snow Leopard). I installed all dependencies like ffmpeg, SDL, etc. using MacPorts. Normally, I use MLT configuration: --enable-gpl --prefix=/opt/local


See the Building on Windows page.

avformat (FFmpeg) module

If you specify nothing and do not disable the module, then MLT attempts to build the avformat module against an installation in the system path. Typically, this means /usr or /usr/local, but actually MLT uses the parent directory of the directory containing the ffmpeg utility in your PATH. For example, if ‘which ffmpeg’ returns /home/me/bin/ffmpeg, then it assumes the prefix was /home/me and expects to locate headers in /home/me/include/ffmpeg and libraries in /home/me/lib. The following options override this behaviour:

  • --avformat-shared=path:

links the MLT module dynamically to a shared build of FFmpeg that was not installed to the system path. The path corresponds to the prefix used when configuring the FFmpeg build and install.

  • --avformat-static=path:

links the MLT module statically to a non-private (not using –avformat-svn), static build of the FFmpeg libraries. The path must refer to the top level source directory that contains libavformat, libavcodec, and libavutil subdirectories.

  • --avformat-ldextra=libs:

lets you specify additional libraries with which to link against when doing a static build. Basically, you need a gcc ‘-l’ option for each external library that you have configured the FFmpeg build.

  • --avformat-suffix=suff:

lets you tell MLT about the –build-suffix option that you used when you configured the FFmpeg build. If you do not understand this, then it usually safe to not include it.

  • --avformat-swscale:

tells MLT that your non-private FFmpeg build uses libswcaler. This is the case if you used the –enable-swscaler option when configuring the FFmpeg build.

  • --avformat-no-devices:

disable linking to libavdevice.

  • --avformat-no-codecs:

only build the filters for resampling, color space conversion, and deinterlace. Do not build producer_avformat or consumer_avformat.

  • --avformat-no-filters:

only build producer_avformat and consumer_avformat and not the filters. The module filename will be instead of to prevent a file name clash.

A distribution that does not want to include FFmpeg codecs for reasons of patent licensing can use –avformat-no-codecs in conjunction with –avformat-static to make a build that statically links just for the valuable audio and video processing functionality of FFmpeg. Then, a community-run repository can provide a mlt-ffmpeg package using –avformat-no-filters to provide a companion plugin for the codecs. To build this sort of package, the package build script can =make -C src/modules/avformat install= instead of the usual high-level default make target.

SoX module

When building, if you get the error “filter_sox.c:40:44: error: missing binary operator before token “(“” then read on…

This is a known issue in some environments because for the longest time sox did not provide a pkg-config .pc file. So, there is some legacy compatibility code in the build system for systems using an older version of sox. In some environments, this legacy code picks up what it perceives to be a valid sox library, but in fact it is not completely usable. The typical workaround for modern systems is to install libsox-dev or sox-devel or similar. Soon I will remove this legacy code, but not right now.

Automated Build Server

A TeamCity server has been setup to automatically make builds and run tests for continuous integration quality control.



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