v6.22.0

This version fixes bugs associated with the preview scaling introduced in the
previous version.

Framework

• Added mlt_properties_exists() and Mlt::Properties::property_exists().
• Added mlt_audio C class with:
  • mlt_audio_new()
  • mlt_audio_close()
  • mlt_audio_set_values()
  • mlt_audio_get_values()
  • mlt_audio_alloc_data()
  • mlt_audio_calculate_size()
  • mlt_audio_plane_count()
  • mlt_audio_plane_size()
  • mlt_audio_get_planes()
  • mlt_audio_shrink()
  • mlt_audio_reverse()
  • mlt_audio_copy()
  • mlt_audio_calculate_frame_samples()
  • mlt_audio_calculate_samples_to_position()
  • mlt_audio_channel_layout_name()
  • mlt_audio_channel_layout_id()
  • mlt_audio_channel_layout_channels()
  • mlt_audio_channel_layout_default()
• Added Mlt::Audio C++ class with:
  • Mlt::Audio::Audio()
  • Mlt::Audio::Audio(mlt_audio_s*)
  • Mlt::Audio::~Audio()
  • Mlt::Audio::data()
  • Mlt::Audio::set_data(void*)
  • Mlt::Audio::frequency()
  • Mlt::Audio::set_frequency(int)
  • Mlt::Audio::format()
  • Mlt::Audio::set_format(mlt_audio_format)
  • Mlt::Audio::samples()
  • Mlt::Audio::set_samples(int)
  • Mlt::Audio::channels()
  • Mlt::Audio::set_channels(int)
  • Mlt::Audio::layout()
  • Mlt::Audio::set_layout(mlt_channel_layout)
• Fixed drop-frame timecode for 59.94 fps.
• Fixed crash on null pointer passed to mlt_consumer_stop().

Modules

• Fixed frei0r transitions with preview scaling.
• Fixed affine ox and oy properties incorrect with preview scaling.
• Fixed a crash and incorrect preview scaling with more than one affine
  filter active on the same frame.
• Fixed preview scaling for the rotoscoping filter.
• Moved some services from gtk2 module to a new gdk module:
  • gtkrescale filter
  • pango producer
  • pixbuf producer
• Deprecated the gtk2 module and no longer enabled by default.
• Deprecated the linsys (DVEO SDI) module.
• Added the sample_fmt property to the avformat consumer.
• Fixed a possible segfault in the mix transition.
• Removed support for text keyframes to the text and qtext filters
  to fix regression on strings containing '='.
• Disable frame-threading with bigsh0t, distort0r, and medians frei0r plugins.
• Added meta.media.%d.stream.projection property the avformat producer.
• Fixed a crash with with filters not supporting preview scale in frei0r
  transitions.
• Fix artifacts in luma transition and affine filter with frame-threading.
• Stop including title="Anonymous Submission" in xml consumer.
• Fixed a crash in opencv.tracker filter.
• Fixed a crash in composite transition if luma file fails to load.
• Added validations in opengl module to prevent asserts in Movit.
• Fixed building with OpenCV 4.
• Changed avformat producer to accept a '?' in argument/resource property
  by escaping it as '?'.
• Changed the background property of the affine filter to be mutable.
• Fixed changing the audio_index property in the avformat producer.
• Changed resample filter to more resiliant to frequency changes.
• Added a video_delay property to the sdl2_audio and rtaudio consumers.
• Add millisecond options to the timer filter.
• Fixed the in point handling for the timewarp producer.
• Fixed some audio gaps and sync issues with the rbpitch filter and timewarp
  pitch compensation.
• Fixed a possible crash caused by producer consumer.
• Changed avformat consumer to set AVOption color_primaries based on the
  MLT colorspace if not already set as property.
• Fixed crop right on image with odd width skews image in crop filter.
• Fixed incorrect silence value for unsigned 8-bit audio in avformat producer.
• Changed qimage to use Qt's internal orientation detection instead of libexif.
• Reduced clicks in mix transition by silencing buffers on discontinuity.
• Improved A/V synchronization in swresample and resample filters - also reduces audio clicks.
• Improved speed of the qimage producer.
• Fixed incorrect color using libx264rgb in avformat consumer.
• Fixed relative paths for avfilters that have the filename option.
• Fixed some avfilters dropping the alpha channel: smartblur, vaguedenoiser.
• Improved performance of the resize filter.
• Fixed an affine filter inside a transition was always nearest neighbor
  interpolation.
• Changed the lift_gamma_gain filter to use round values up.

Other

• Fixed melt option -group applies to an implicit consumer.
• Added -quiet option to melt (implies -silent but more so).
• CMake build improvments adding modules:
  • gdk
  • jackrack
  • lumas
  • resample
  • sox
  • vorbis
• Added avformat consumer presets:
  • Slide-Deck-H264
  • Slide-Deck-HEVC
• Removed "intra=1" from some avformat presets (use g=1 for intra only):
  • intermediate/MPEG-2
  • intermediate/MPEG-4
  • lossless/H.264
• Fixed using Qt, Movit, and WebVfx in the official docker image:
  https://hub.docker.com/repository/docker/mltframework/melt
  IMPORTANT: it now requires docker run with the --init option.

v6.20.0

This version adds support for low resolution preview scaling and adds a
module based on librubberband for audio pitch-shifting.
An official docker image is now available at
https://hub.docker.com/repository/docker/mltframework/melt

Framework

• Added consumer scaling:
  • mlt_profile_scale_width()
  • mlt_profile_scale_height()
  • Mlt::Profile::scale_width()
  • Mlt::Profile::scale_height()
  • support for a double "scale" property to melt and the xml producer
• Fixed mlt_properties_set() with an invalid expression.
• Added new functions that do not evaluate expressions:
  • mlt_properties_set_string()
  • Mlt::Properties::set_string()
• Improved the service-caching heuristic in mlt_multitrack.
• Fixed possible crashes in mlt_playlist get_frame() and mlt_filter_process().

Modules

• Added the rubberband module with a rbpitch filter.
• Added pitch compensation to timewarp producer.
• Added the invert_scale property to the affine filter and transition.
• Added the reverse property to shape filter.
• Added support for text keyframes to the text and qtext filters.
• Added support for the CSRT and MOSSE algorithms in opencv.tracker filter.
• Fixed a crash on empty algo property in the opencv.tracker filter.
• Changed vorbis module to no longer be deprecated.
• Improved colorspace conversions in the avformat module.
• Fixed audio artifacts on initial seek to in point in avformat producer.
• Fixed the colorspace of the cached image in avformat producer.
• Fixed white video flashes on property changes in the qtext filter.
• Fixed a crash in the rotoscoping filter with large spline deviations.
• Fixed a crash in the sdi consumer if the driver is not loaded.
• Improved support for a video clip as luma producer to the luma transition.
• Fixed a crash in the matte transition.
• Fixed a crash when using invert property =1 in the composite transition.

Other

• Added a Dockerfile and integrated docker build into Travis CI.
• Added more avformat consumer presets:
  • intermediate/DNxHR-HQ
  • intermediate/ProRes HQ
  • ALAC
  • FLAC
  • Fixed some parameters in the XDCAM and D10 avformat presets.
  • Fixed link failure on some CPU architectures.

v6.18.0

This version is a general maintenance release with a bunch of fixes, improvements, and additions.

Framework

• Fixed some data races in mlt_consumer, mlt_deque, and mlt_property.
• Fixed the mlt_events listener incorrect owner argument.
• Added support for the LC_ALL environmant variable on Windows.
• Fixed the argument to mlt_factory_init() not working on Windows.
• Fixed mlt_service_identify() not reliable in some use cases.
• Added some default and copy constructors and assignment operators to mlt++
  • Filter()
  • Filter( const Filter &filter )
  • Filter& operator=( const Filter &filter )
  • Producer( const Producer &producer )
  • Producer& operator=( const Producer &producer )
  • Properties( const Properties &properties )
  • Properties& operator=( const Properties &properties )
  • Service( const Service &service )
  • Service& operator=( const Service &service )
  • Transition()
  • Transition( const Transition &transition )
  • Transition& operator=( const Transition &transition )
• Added mlt_luma_map:
  • mlt_luma_map_init
  • mlt_luma_map_new
  • mlt_luma_map_render
  • mlt_luma_map_from_pgm
  • mlt_luma_map_from_yuv422
• Fixed preset overrides depend on the XML attribute order.
• Fixed serializing an animated property with a new length.

Modules

• Fixed interpolation in rotoscoping filter.
• Fixed crop filter not working with color producer.
• Fixed some data races in the sdl and sdl2 consumers.
• Fixed some data races in the avformat producer.
• Added a movit.flip filter to the opengl module.
• Fixed using filters on frei0r producers.
• Added support for in and out attributes on the consumer xml element.
• Fixed using an in point with the multi consumer.
• Fixed avfilter fails if the image size changes.
• Fixed showing superfluous decimals for seconds in the timer filter.
• Stop serializing an invalid producer as an "INVALID" text producer in xml.
• Fixed an access violation crash in wave filter.
• Added the meta.media.color_range property to the avformat producer.
• Fixed full range yuv422p not converted correctly in the avformat producer.
• Fixed the text filter not working with pango.
• Fixed a regression using dynamictext with pango.
• Added a position property to avfilter for filters that need position info.
• Fixed avfilter.subtitles not using the source position.
• Added an analyze property to vidstab filter. When set, analysis only starts
  and the results file written if true.
• Fixed crash combining the affine filter with the shape filter.
• Added interlace detection from AVCodecContext.field_order.
• Changed the avformat producer to not use the rescale.interp frame property.
  Previously, when reacale.interp == "nearest", it would relax seeking. Now, seek
  accuracy is reduced during trick play (rewind or fast forward).
• Fixed swscale flags for auto-inserted scalers in avfilter.
• Fixed a double free crash in ladspa filter on channel count mismatch.
• Refactored the composite and luma transitions to use mlt_luma_map.
• Refactored the pgm producer and shape filter to use mlt_luma_map.
• Refactored the lumas module to use mlt_luma_map.
• The lumas module is now disabled by default and must be explicitly enabled.
• Added property animation to the threshold filter.
• Added a cairoblend_mode filter to the frei0r module to affect a
  frei0r.cairoblend transition used to composite/blend tracks.
• Added support for new vaapi options to the avformat consumer:
  • connection_type: x11 or drm
  • driver
  • kernel_driver
• Fixed the timewarp producer with a colon in the filename.
• Fixed a relative file name with a colon in it in the xml producer.
• Fixed defaulting to album or poster art if there is another video stream.
• Fixed parameter animation in frei0r plugins when using frame threads.
  This change also enables frame-threading for more plugins.
• Improved the qtblend filter to not process alpha if no transparency.
• Added a background_color property to the qtblend filter.
• Fixed the opencv.tracker incorrect behavior on cut clips.
• Changed opencv.tracker to store absolute frame numbers.
• Fixed incorrect frame offset on render in opencv.tracker.
• Add an alpha_over property to luma transition. This addresses a behavior
  regression in version 6.14.0.
• Fixed noimagecache not working in the avformat producer.

Other

• Mlt++ now requires C11 compiler support.
• Fixed closing melt SDL2 window from window manager (i.e. close button).
• Added -repository option to the melt command.
• Added unit tests for Mlt::Event.
• Fixed returning image data for Python 3.
• Switch to python3 by default.
• Updated the prores encoding presets to set vendor ID and colr atom.
• Added a CMake build system. This is not yet prefered over the existing
  configure script and Makefiles and has less flexibility. It is a start and
  has limited support.

v6.16.0

This version is released to facilitate packaging the latest version of Shotcut,
which is using new APIs.

Framework

Added functions to get/set a creation date to a producer:

• mlt_producer_get_creation_time()
• mlt_producer_set_creation_time()
• Mlt::Producer::set_creation_time()
• Mlt::Producer::get_creation_time()

Modules

• Fixed dance filter not showing when lower track is transparent.
• Refactored dynamictext filter to use mlt_producer_get_creation_time().
• Marked frei0r rgsplit0r plugin version < 1.1 as not thread-safe.
• Fixed possible null pointer crash in mlt_properties_serialise_yaml().

v6.14.0

This version is mostly fixes plus a few API additions and filters.

Framework

• Added mlt_profile_lumas_dir().
• Added mlt_frame_get_unique_properties().
• Added mlt_playlist_reorder() and Mlt::Playlist::reorder().
• Added some new convenience constructors to mlt++
  • Producer(mlt_profile profile, const char *id, const char *service = NULL)
  • Consumer(mlt_profile profile, const char *id , const char *service = NULL)
  • Transition(mlt_profile profile, const char *id, const char *arg = NULL)
  • Filter(mlt_profile profile, const char *id, const char *service = NULL)
  • Tractor(mlt_profile profile, char *id, char *arg = NULL)
• Added Mlt::Transition::connect(Service&).
• Added unit tests for mlt_playlist.
• Fixed a crash on invalid transition track values in mlt_transition.
• Fixed a deadlock regression in v6.12.0 of mlt_consumer when starting from
  a paused state (producer speed=0).

Modules

• The avformat module now requires at least FFmpeg v2.4 or Libav 12.
• Added mask_start and mask_apply filters to the core module.
• Added qtext filter to qt module.
• Changed dynamictext and timer filters to use qtext.
• Fixed number of digits for seconds in timer filter.
• Added mlt_image_format property to color producer.
• Improved color accuracy of libswscale RGB->YUV conversion.
• Fixed frei0r producer not working with tractor.
• Fixed decklink consumer stalling on dropped frames.
• Generate lumas for 16:9, 9:16 (vertical), and square aspect ratios.
• Fixed crash in qimage when alpha_size is zero.
• Fixed the mlt_consumer channels property not being passed to multi consumer.
• Fixed the shape filter for full range color and crashes.
• Converted the shape filter to use mlt_animation.
• Added a use_mix property to the shape filter.
• Fixed invert=1 and mix=100 gives wrong image in shape filter.
• Fixed a possible free null pointer in the linsys sdi consumer.
• Fixed using destroyed temporary object in qimage.
• Fixed a possible null pointer dereference in the spot_remover filter.
• Fixed memory leak on swr_convert() failure in swresample filter.
• Fixed possible null pointer dereference in affine when not using rect.
• Fixed loading image sequence on Windows in qimage.
• Fixed some null pointer crashes using Movit opengl services.
• Fixed sdl2 consumer crashes during initialization on Linux or BSD.
• Fixed distorted image using melt_file.
• Fixed qimage build on Qt version < 5.5.
• Added offset property to the timer filter.
• Changed the boxblur hori & vert properties' minimum to 0.
• Fixed crash in duplicate frame on rotated videos.
• Added automatic scaling and padding to avfilter.
• Fixed field order when encoding progressive as interlace.
• Fixed frei0r plugins to use the number of slices from the threads property.
• Fixed over compositing with transparent clips in luma transition.
• Added sliced processing to dissolve-with-alpha using the threads property.
• Added createdate keyword to dynamictext filter.
• Fixed possible crash changing audio_index in avformat producer.
• Fixed small memory leaks in xml consumer, jackrack, and timewarp producer.
• Fixed compiling opencv module with OpenCV > 3.

Other

• Added vertical video profiles:
  • vertical_hd_30
  • vertical_hd_60
• Mlt++ now requires C++11 compiler support.
• Added --disable-windeploy to configure to keep bin & lib folders on Windows.
• Added support for consumer in & out to melt.
• Fixed color accuracy of lossless/Ut Video preset and use pix_fmt yuv422p.
• Fixed x264 lossless preset to use crf=0.
• Fixed compiling with mingw32.
• Fixed build with Python 3.

v6.12.0

This version has many important fixes plus a few new filters and support for
encoding using VA-API.

Framework

• Changed buffer property to be mutable and adaptive to speed property in
  mlt_consumer.
• Changed macOS RELOCATABLE build to use standard app bundle layout:
  • lib/mlt -> ../PlugIns/mlt
  • lib/frei0r-1 -> ../PlugIns/frei0r-1
  • lib/ladspa -> ../PlugIns/ladspa
  • share/mlt -> ../Resources/mlt
  • share/movit -> ../Resources/movit
• Fixed a_track of transitions matching deleted track in
  mlt_tractor_remove_track().
• Fixed multi-thread race crash in mlt_properties_clear().
• Fixed possiblle null pointer crash in mlt_property_get_rect() and
  mlt_property_get_time().
• Fixed non-animated strings containing ';' or '=' in mlt_animation_parse().
• Fixed crash in clear_property() with mlt_animation.

Modules

• Added a generic text filter to the plus module.
• Added a timer filter to the plus module.
• Added audio timeout handling to sdl2 consumers.
• Added spot_remove filter to the plus module.
• Added dds, ico, and webp filename extensions for qimage producer.
• Added support for color_range property in avformat consumer:
  "pc" or "jpeg" for full range, otherwise limited range.
• Added a window property to the audiowaveform filter.
• Added MM:SS.SS to the timer filter.
• Added query string param "multi" to the xml producer to force using the
  multi consumer.
• Improved WebP image support in avformat producer.
• Integrated hwupload filter in avformat consumer if using VAAPI codec.
• Changed count producer to use pango if qtext not available.
• Changed qt moduled to not call XInitThreads()
• Changed color producer to only set alpha on frame if rgb24a requested or
  not opaque.
• Changed the xml producer to pass quality and performance parameters to the
  multi consumer.
• Fixed sdl2_audio distortion (regression in v6.10.0).
• Fixed dynamictext filter to not error on empty text.
• Fixed dynamictext aliased (regression in v6.10.0).
• Fixed qimage outputs premultiplied if scaled internally.
• Fixed crash in cbrts consumer if running property was never set.
• Fixed rendering edges of some typefaces in qtext producer.
• Fixed qimage fails to load with wrong filename extension.
• Fixed affine dark right and bottom edge artifacts regression in (v6.10.0).
• Fixed support for vp8 and vp9 with alpha channel in avformat producer.
• Fixed interpolation mode selection in qimage producer.
• Fixed crash in qimage with alpha channel.
• Fixed some AAC MP4 files start playing from middle in avformat producer.
• Fixed crash in avfilter if initialization fails.
• Fixed crash in mix when frame rate is very low.
• Fixed crash on missing luma file in composite transition.
• Fixed A/V sync on some files in avformat producer.
• Fixed seeking on audio filter with album art in avformat producer.
• Fixed colorspace conversion in avformat consumer.

Other

• Added more avformat consumer presets:
  • alpha/Quicktime Animation
  • alpha/vp8
  • alpha/vp9
  • alpha/Ut Video
  • lossless/Ut Video
• Added square video profiles:
  • square_1080p_30
  • square_1080p_60
• Added support for nodejs to the swig bindings.
• Changed configure script to require opencv module be explicitly enabled.
• Numerous spelling fixes in source code and comments thanks to codespell.

v6.10.0

This version fixes bugs and supports serializing animation keyframes with a
specified time format (previously only frame number).

Framework

• Reverted mlt_pool change in v6.8.0 pending further testing.
  (USE_MLT_POOL compiler define is now a 0/1 boolean, defaults to 1.)
• Fixed crash regression in v6.8.0 "parsing non-animated string as an animation."
• Added pointer checks to mlt_animation.
• Changed producer cache size heuristic in mlt_multitrack to be more liberal.
• Fixed handling reserved characters in names for YAML in mlt_properties.
• Added clamping to prevent computing negative in and out points to mlt_producer.
• Added functions to serialize animation with a time format:
  • mlt_animation_serialize_cut_tf()
  • mlt_animation_serialize_tf()
  • mlt_property_get_string_tf()
  • mlt_property_get_string_l_tf()
  • mlt_properties_get_value_tf()
  • Mlt::Properties::get(int, mlt_time_format)
  • Mlt::Animation::serialize_cut(mlt_time_format, int, int)
• Added functions to clear a property to mlt_properties:
  • mlt_property_clear()
  • mlt_properties_clear()
  • Mlt::Properties::clear()

Modules

• Fixed enabling sliced pix_fmt conversion in avformat producer.
• Fixed incorrect seek and sync on audio files with discard packets.
• Added support for avcodec_send_frame() API to avformat consumer.
• Fixed compile errors with Libav master.
• Fixed a crash in affine transition.
• Fixed a crash in ladspa filters when consumer frame rate is low (e.g. <= 8).
• Fixed a crash in boxblur filter.
• Added animation support to boxblur hori and vert properties.
• Fixed a crash in movit.convert.
• Fixed incorrect alpha in affine transition blending routine.
• Converted frei0r from deprecated mlt_geometry to mlt_animation API.
• Fixed tilde in text string for pango producer.
• Fixed using more than one channelcopy filter.
• Fixed the mono filter reducing volume level.
• Fixed degraded audio scrubbing in sdl2_audio consumer.
• Converted dynamictext filter to use affine transition for more correct
  alpha compositing and sub-pixel positioning.
• Added time format support for animation keyframes to the xml consumer.
• Added animation support to more affine transition properties:
  • fix_rotate_x
  • fix_rotate_y
  • fix_rotate_z
  • fix_shear_x
  • fix_shear_y
  • fix_shear_z
  • ox
  • oy
  • scale_x
  • scale_y
• Fixed gaps in text when characters overlap in qtext and kdenlive producers.
• Fixed a crash in pixbuf producer with multiple render threads.
• Converted the oldfilm vignette filter from mlt_geometry to mlt_animation.

Other

• Numerous updates to mlt-xml.dtd.
• Categorized many of the encode presets (using meta.preset.name).

v6.8.0

Framework

• Added support for musl C library.
• Added functions for audio channel layouts:
  • mlt_channel_layout_name()
  • mlt_channel_layout_id()
  • mlt_channel_layout_channels()
  • mlt_channel_layout_default()
• Added channel_layout property to mlt_consumer.
• Added mlt_channel_layout enum.
• Disabled memory pooling by default and require compile macro USE_MLT_POOL
  to re-enable it.
• Fixed reliability of keyframed properties serializing properly.
• Fixed parsing non-animated string as an animation.
• Added more functions to mlt_animation:
  • mlt_animation_key_set_type()
  • mlt_animation_key_set_frame()
  • Mlt::Animation::key_set_type()
  • Mlt::Animation::key_set_frame()

Modules

• Fixed some crashes in qimage producer especially with alpha channel.
• Fixed >2 channel audio output in the SDL consumers.
• Fixed >2 channel audio output in the rtaudio consumer on Windows.
• Fixed vorbis encoding with FFmpeg v3.4+.
• qimage and qtext are now higher priority than gtk2 pixbuf and pango by the
  loader producer.
• Added support for more channel counts to decklink consumer.
• Added swresample filter based on libswresample from FFmpeg. This is now
  the preferred channel count normalizing filter used by the loader producer.
• Fixed the strange "Undefined constant" and "Unable to parse option value"
  log messages in the the avformat consumer.
• Fixed GIF and DPX writing in avformat consumer.
• Reduced the memory usage of the affine transition and filters.
• Fixed a crash in kdenlivetitle producer.
• Fixed a crash in the rotoscoping filter.
• Fixed frame rate reported in Matroska and WebM files produced by the
  avformat consumer.
• Added sdl2_audio consumer.
• Fixed alpha channel support for more pixel formats in the avformat producer.
• Converted the affine transition to use mlt_rect and mlt_animation.
• Fixed LADSPA plugins with mono channel audio.

Other

• Fixed a melt command line parsing bug when argument supplied to -transition.
• Fixed melt with SDL2 on Windows not using stdio and stderr.
• Improved speed of the vp9 avformat consumer preset.

v6.6.0

This version builds upon the previous release with performance improvements
using the sliced image processing framework. It also improves compatibility
with dependencies (FFmpeg, Qt 5, SDL 2, NDI, OpenCV, libebur128).

Framework

• Added a thread pool to mlt_slices:
  • mlt_slices_run_normal()
  • mlt_slices_run_rr()
  • mlt_slices_run_fifo()
  • mlt_slices_count_normal()
  • mlt_slices_count_rr()
  • mlt_slices_count_fifo()
  • MLT_SLICES_COUNT environment variable
• Added mlt_log_timings_now() to mlt_log.
• Added mlt_image_yuv422p16 image format.
• Added mlt_image_format_planes() and mlt_image_format_id() to mlt_frame.
• Added mlt_service_disconnect_all_producers() and
  Mlt::Service::disconnect_all_producers()
• Fixed accuracy of mlt_time_format conversions.
• Fixed mlt_filter_get_progress() never reaching 1.0.
• Fixed divide by zero in mlt_filter_get_progress().

Modules

• Added sdl2 module!
• Added sum property to mix transition for simple mixing without dynamics.
• Added TLD and KCF tracking modes to opencv module.
• Added CSV (comma-separated values) simple slideshow to pixbuf producer.
• Added jack filter to jackrack module.
• Added sliced processing to frei0r.
• Added sliced processing to composite transition.
• Added sliced processing to avformat producer pixel format conversion.
• Added sliced processing to affine transition and filter.
• Converted volume and pan filters to floating point.
• Added rotate_center property to qtblend transition and filters.
• Added meta.media.variable_frame_rate (VFR detection) to avformat producer.
• Added support for external libebur128.
• Updated internal libebur128 to latest.
• Added 10-bit capture to decklink producer.
• Added mlt_image_yuv422p16 to fieldorder filter, avcolour_space filter, and
  avformat consumer.
• Added no_profile property to xml consumer.
• Various ndi module fixes and improvements.
• Fixed setting color_trc in multi consumer.
• Fixed kdenlive title transparency.
• Fixed incorrect alpha channel breaking freeze filter with qtblend transition.
• Fixed transparency of pixbuf images with qtblend transition.
• Fixed some crashes in new qtblend transition.
• Fixed building qt module with C++11 for Qt 5.7+.
• Fixed reporting accurage length for image sequences in qimage and pixbuf.
• Fixed extra audio samples added to end of file in avformat consumer.
• Fixed rawvideo export in avformat consumer.
• Fixed multi-threading wtih FFmpeg 3.2+ in avformat module.
• Fixed JPEG album art in avformat producer.
• Removed filter_avresample (dropped by FFmpeg).
• Stop flushing audio buffer in decklink consumer.
• Fixed field order handling in decklink consumer.
• Make composite transition field order aware.
• Fixed nesting mlt_tractor with opengl module.
• Fixed kdenlive titler crash on resized frame.

Other

• Various memory leak fixes.
• Fixed opening files with extended chars on Windows (framework and modules).

v6.4.1

This is a hot-fix release for v6.4 that fixes a symbol version declaration problem for the new C++ method Mlt::Profile::is_valid().