Thursday, September 10, 2015

SMPTE 2022-2 Output Added

Thanks to the sponsorship of BCE (Broadcast Centre Europe), the git version of the cbrts consumer now includes SMPTE 2022-2 RTP/UDP output. It has been successfully tested for 36 hours of continuous playback with an ateme DR8400 IRD and the DecTek StreamXpert performing PCR analysis and TR 101 290 monitoring.

Wednesday, July 29, 2015

Version 0.9.8 Released

In addition to the exciting new audio/visualization filters mentioned in the previous blog post, this version features some exciting API improvements for manipulating multitracks and property animations. There are still many services, however, that need updating to support animated properties. Also, since SourceForge is still recovering from a storage problem preventing the upload of new files, you can download the release source archive from GitHub.


  • Added mlt_service_disconnect_producer() and Mlt::Service::disconnect_producer().
  • Added mlt_multitrack_disconnect() and Mlt::Multitrack::disconnect().
  • Added mlt_tractor_remove_track() and Mlt::Tractor::remove_track().
  • Added mlt_service_insert_producer() and Mlt::Service::insert_producer().
  • Added mlt_multitrack_insert() and Mlt::Multitrack::insert().
  • Added mlt_tractor_insert_track() and Mlt::Tractor::insert_track().
  • Added mlt_transition_set_tracks() and Mlt::Transition::set_tracks().
  • Added Mlt::Properties::get_animation().
  • Added Mlt::Properties::get_anim().
  • Added Mlt:Animation class with methods:
    • length()
    • is_key()
    • keyframe_type()
    • get_item()
    • next_key()
    • previous_key()
    • set_length()
    • remove()
    • interpolate()
    • serialize_cut()
  • Added mlt_animation_key_count() and Mlt::Animation::key_count().
  • Added mlt_animation_key_get() and Mlt::Animation::key_get().


  • Added audiowaveform video filter.
  • Added fft audio filter.
  • Added dance video filter (uses fft).
  • Added lighshow video filter (uses fft).
  • Added distort property to movit.rect video filter.
  • Added rotate property to pango video producer.
  • Added 2K DCI and 4K modes to decklink producer and consumer.
  • Added audiomap (channel remapping) filter.
  • Added property animation to all LADSPA audio filters and producers.

Thursday, June 18, 2015

New Audio Visualization Filters

MLT developer, Brian, developed 4 new filters, available now in git master. The fft filter uses the fast Fourier transform to produce data for other filters. The dance filter moves, scales, and rotates an image or video in reaction to the audio characteristics. The lightshow filter alters the color of the image based on the audio. Lastly, the audiowaveform filter draws a waveform over the image.

These were all sponsored by the "Learn Your Lyrics" YouTube channel. They generate the videos using MLT through shell scripts that generate long melt command lines. You can see the fft, dance, and audiowaveform filters in action in this video:

Sunday, March 1, 2015

Version 0.9.6 Released

A major regression slipped into the 0.9.4 release plus some other good fixes rolled in just afer that release prompting this new release. Please discontinue using version 0.9.4 and upgrade.

Monday, February 16, 2015

version 0.9.4 released

This is a bugfix and minor enhancement release. Here are some of the notable changes and enhancements.


  • Added color_trc (transfer characteristic) property to mlt_consumer and mlt_frame.
  • Added Mlt::Profile::set_display_aspect(int, int).
  • Added mlt_pool_stat().
  • Added mlt_smpte_df and mlt_smpte_ndf to mlt_time_format for non-drop-frame timecode support.
  • Added Mlt::Tractor::Tractor(Mlt::Profile&).
  • Added mlt_frame_get_alpha().
  • Added default, copy, and assignment methods to Mlt::Frame.
  • Added Mlt::Filter::process(Mlt::Frame&).


  • Added support for color_trc property to avformat and opengl modules.
  • Performance improvements for composite and matte transitions.
  • Added fill, halign, and valign properties to affine transition and filter.
  • Added producer.* and consumer.* properties to consumer producer.
  • Fixes for libavformat and libavcodec v56.
  • Dropped support for FFmpeg < v1.0 and Libav < v9.
  • Added a lumakey filter.
  • Added a localtime property to dynamictext filter.
  • Added date/time format string support to dynamictext filter.
  • Added no_root property to xml consumer.
  • Added audio-only tone producer.
  • Added drop property to count producer.
  • Added caching to pango producer to improve performance.


  • Added WMV and WMA avformat consumer presets.
  • Added a ProRes-Kostya avformat consumer preset.
  • Changed VP9 WebM preset to use Opus audio codec.
  • Added 4K UHD and 2.5K QHD profiles.
  • Added x265-medium and x265-medium-pass1 avformat consumer presets.
  • Added a unit test for Mlt::Frame.

Monday, November 3, 2014

Meltytech Acquires Copyrights from Ushodaya

Ushodaya Enterprises Limited of India, the original sponsor of the MLT and Melted projects has assigned their copyrights to Daniel R. Dennedy, sole proprietor and CTO of Meltytech, LLC. What does that mean? Not much. There are no planned changes to project direction at this time, but it may provide some options in the future. It is just good to have the copyrights under control of active members of the project to make it possible to exercise future options. Many thanks to project co-founder, BGa, for facilitating this transaction.

Tuesday, October 28, 2014

Synfig Studio uses MLT for cross-platform sound

Synfig Studio is a good, free, open source, cross-platform 2D animation program. They wanted to add audio support, but they needed more than just a hardware abstraction layer for audio output. They needed more than a multi-format/-codec library. They also wanted something that provides timing and mixing with a succinct API. They chose MLT.