v7.0.0 released

May 2, 2021

You can download it from GitHub.

This is a major new version that breaks API to add a major new feature to the framework: retiming. This is accomplished through new classes mlt_chain and mlt_link. And since we are breaking API we decided to clean house by removing deprecations and switching the build system over entirely to CMake. For more information see our migration guide. More documentation about the new chain and link classes is still pending.


  • Added mlt_chain and Mlt::Chain classes.
  • Added mlt_link and Mlt::Link classes.
  • Added a link value to service type in the service metadata schema.
  • Added a boolean animation parameter attribute to the service metadata schema.
  • Added mlt_animation_shift_frame() and Mlt::Animation::shift_frames().
  • Added mlt_animation_get_string().
  • Fixed using a stale cached property animation string.
  • Added mlt_image and Mlt::Image classes.
  • Remove legacy “height + 1” workaround in image allocation.
  • Fixed a crash on setting timewarp speed higher than 23x.
  • Added mlt_audio_silence().
  • Removed mlt_image_opengl.
  • Replaced variadic arguments in mlt_events with new mlt_event_data APIs.
  • Removed mlt_geometry APIs.
  • Renamed mlt_image_rgb24a as mlt_image_rgba.
  • Renamed mlt_image_rgb24 to mlt_image_rgb.
  • Renamed mlt_image_glsl to mlt_image_movit.
  • Renamed mlt_image_glsl_texture to mlt_image_opengl_texture.
  • Removed virtual function mlt_frame::get_alpha_mask().
  • Removed mlt_frame_get_alpha_mask().
  • Removed deprecated functions:
    • mlt_sample_calculator
    • mlt_sample_calculator_to_now
    • mlt_channel_layout_name
    • mlt_channel_layout_id
    • mlt_channel_layout_channels
    • mlt_channel_layout_default
    • mlt_slices_init
    • mlt_slices_close
    • mlt_slices_run
    • mlt_playlist_move_region
    • Mlt::Playlist::move_region
  • Fixed a rounding error calculating display aspect ratio in mlt_profile_from_producer().


  • Added a timeremap link to the core module with animatable map property. (Speed can increase or decrease between keyframes including reverse.)
  • Added chain and link XML elements to xml module.
  • Added “meta.media.has_b_frames” property to avformat producer.
  • Removed deprecated modules:
    • dv
    • gtk2 (not gdk)
    • kino
    • linsys
    • lumas
    • motion_est
    • swfdec
    • videostab
  • Removed the following services:
    • data_feed filter
    • data_show filter
    • region filter and transition
    • sdl_image
  • Converted filters to use new mlt_image class:
    • brightness
    • imageconver
    • mirror
    • spot_remover
  • Deprecated the audiowave filter.
  • Added the ability to build the jackrack module without JACK to get only LADSPA producers and filters.
  • Deprecated start and end properties for the following filters:
    • brightness
    • panner
    • boxblur
    • wave
    • volume
  • Removed deprecated font property from pango producer.
  • Improved album art (attached pic) detection in avformat producer.
  • Improved the resample filter to have less artifacts and use less memory.


  • CMake: nearly complete rewrite.
  • Removed the old configure bash scripts and Makefiles.
  • Added -chain and -link options to melt command line.



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