Version 7 Migration Guide

The purpose of this document is to explain how to migrate a MLT major version 6 application to major version 7. Version 7 is still in development and is expected to be released by May, 2021. There is a v7 branch in git. See the Road Map for more information about the plans. This document only includes what has been implemented thus far. It will be updated as changes are merged into the v7 branch and then from v7 to master just prior to release.


  • The build system has moved completely to CMake. Read the top-level CMakeLists.txt for the options.
  • The major version is now part of the library name as well as the installed:
    • pkg-config files (mlt-framework-7.pc and mlt++-7.pc),
    • modules (lib/mlt-7/),
    • headers (include/mlt-7/),
    • and data (share/mlt-7/).
  • As a result, you may need to change how you are locating the MLT package or overriding things to access modules.
  • The mlt++ headers are installed to include/mlt-7/ instead of being separate.
  • There is no more mlt-config and only pkg-config.
  • Old make targets dist, validate-yml, codespell, and uninstall are gone.


  • Since luma file generation was removed, see documentation for mlt_luma_map.
  • mlt_geometry is removed
  • mlt_events has changed majorly:
    • mlt_transmitter was removed as being unnecessary
    • mlt_event_data was added and replaces the variable arguments to mlt_events_fire() and mlt_listener().
  • mlt_image_rgb24a is renamed to mlt_image_rgba
  • mlt_image_rgb24 is renamed to mlt_image_rgb
  • mlt_image_glsl is renamed to mlt_image_movit
  • mlt_image_glsl_texture is renamed to mlt_image_opengl_texture
  • mlt_image_opengl is removed


  • The following modules have been removed. Most of them were previously indicated as deprecated:
    • dv
    • feeds
    • gtk2 (not gdk, which still exists and provides the important pango and pixbuf producers.)
    • kino
    • linsys (provided the sdi consumer, not to be confused with decklink)
    • motion_est
    • swfdec
    • videostab (superceded by vid.stab)
    • lumas (replaced with the mlt_luma_map API in v6.18.0)
      This means there will no longer be files generated, but the old file names like %luma01.pgm are still supported, are generated dynamically, and adapt to the mlt_profile resolution.
  • The opengl module is renamed to movit but the names of the services are the same.
  • The services of the vmfx module were moved into plus but the names of the services are the same.
  • The following services have been removed:
    • core/data_feed
    • core/data_show
    • core/region transition and filter



Subscribe to News via RSS.

Recent Posts


MLT enables you to author, manage, and run multitrack audio/video compositions.
See our Hall of Fame
Copyright © 2008-2018 by Meltytech, LLC.

Social Links