API: fix ReaLearn crash
API: support GetSetMediaTrackInfo(P_PROJECT)
MIDI hardware: allow saving project/other limited UI actions while waiting for a hung MIDI device
add ALSA MIDI support, do not show MIDI-only devices in audio configuration
add system hidpi detection, can disable using ui_scale_auto=0 in reaper.ini, or override using ui_scale=
reuse existing REAPER instances when opening files from desktop environment (use -newinst command line parameter to override) ...
add retry button to audio/MIDI device error window
warn when a previously-enabled device is not connected (you may see new warnings about MIDI devices from your past)
show previously-connected devices in device list, allow forgetting those devices ...
do not default to square envelope points on parameters that have a large number of steps defined •
improve win32/mac plug-in filename parsing for projects saved on linux
Notation editor: NEW in 5.20 - Compose and edit MIDI as musical notation, or view and edit recorded MIDI. Flexible mouse editing, key signatures, multiple clefs, dynamics, voices, lyrics, tuplets, articulation, ornaments, slurs, and more.
FX:VST3 support, sample-accurate automation for VST3 and JSFX, FX browser improvements.
ReaScript:API and scripting improvements, including a built-in development environment for creating and debugging scripts in Lua, EEL, or Python. Create anything from simple macros, to complex new functionality.
Control grouping:Flexible, automatable VCA control. Link groups of track controls together at any point in the signal flow.
Video:Many improvements to video support and performance, including real-time programmable track and item effect processing.
FX parameter automation:Full automation and MIDI/OSC learn support for per-take FX, improved FX envelope and modulation management via the Project Bay, increased automation recording speed.
New GUI layouts, Media Explorer improvements, metronome beat patterns, Opus support, MIDI note-off editing, new volume envelope modes, new actions and API functions, and many other fixes and improvements