This delayed release was mainly a bug fixing release but there
are significant new opcodes, including support for simpler use of MIDI
controls and a new opcode to connect to an Arduino. Also there is an
optional limiter in the sound output chain.

Also there are a number of new filters including including the final
opcode written by the 'father of computer music' Max Mathews (with
Julius Smith)! ported by Joel Ross.

-- The Developers

USER-LEVEL CHANGES

New opcodes

• cntDelete deletes a counter object

• lfsr, a linear feedback shift register opcode for pseudo random
  number generation.

• ctrlsave stores the current values of MIDI controllers in an array.

• turnoff3 extends tuning off to remove instrument instances that are
  queued via scheduling but not yet active.

• ctrlprint prints the result of a ctrlsave call in a form that can be
  used in an orchestra.

• ctrlprintpresets prints the MIDI controller preset.

• ctrlselect selects a preset for MIDI controller values.

• ctrlpreset defines a preset for MIDI controllers.

• outall writes a signal to all output channels.

• scale2 is similar to scale but has different argument order and has
  an optional port filter.

• aduinoReadF extends the arduino family to transfer floating point
  values.

• triglinseg and trigexpseg are triggered versions of linseg and
  expseg

• vclpf is a 4-pole resonant lowpass linear filter based on a typical
  analogue filter configuration.

• spf is a second-order multimode filter based on the Steiner-Parker
  configuration with separate lowpass, highpass, and bandpass inputs
  and a single output.

• skf is a second-order lowpass or highpass filter based on a
  linear model of the Sallen-Key analogue filter.

• svn is a non-linear state variable filter with overdrive control
  and optional user-defined non-linear map.

• autocorr computes the autocorrelation of a sequence stored in an array.

• turnoff2_i is init-time version of turnoff2.

• scanu2 is a revision of scanu to make it closer to the original
  concept. Damping now a positive value and plucking initialisation
  totally rewritten, plus various code improvements.

• st2ms and ms2st are stereo to MS and vice-versa conversion opcodes
  with stereo width control.

• mvmfilter is a filter with pronounced resonance and controllable decay time.

###New gen

• gen44 allows the writing of stiffness matrices for scanu/scanu2 in a
  textual format.

Orchestra

• The operations += and -= now work for i and k arrays.

• k-rate array operators are now only processed at k-rate.

Score

• An instance of a named instrument can have a decimal fraction added
  to the name to allow for tied notes and other facilities that were
  only avaliable for numbered instruments.

Options

• New options --limiter and --limiter=num (where num is in range (0,1]
  inserts a tanh limiter (see clip version2) at the end of each k-cycle.
  This can be used when experimenting or trying some alien inputs to save
  your ears or speakers. The default value in the first form is 0.5

• A typing error meant that the tag was not recognised,
  although the English spelling (CsSortLicence) was. Corrected.

• New option --default-ksmps=num changes the default value from the
  internal fixed number.

• New environment variable CS_USER_PLUGINDIR has been added to
  indicate a user plugin dir path (in addition to the system plugin
  directory). This added search path defaults to standard locations
  on different platforms (documented in the manual).

Modified Opcodes and Gens

• slicearray_i now works for string arrays.

• OSCsend always runs on the first call regardless of the value of kwhen.

• pvadd can access the internal ftable -1.

• pan2 efficiency improved in many cases.

• Add version of pow for the case kout[] = kx ^ ivalues[]

• expcurve and logcurve now incorporate range checks and corrects end
  values.

• Streaming LPC opcodes have had a major improvement in performance
  (>10x speedup for some cases) due to a new autocorrelation routine.

• Restriction on size of directory name size in ftsamplebank removed.

• If a non string is passed to sprintf to be formatted as a %s an error
  is signalled.

• readk family of opcodes now support comments in the input which is ignored.

• Added iflag parameter to sflooper.

• Opcodes beosc, beadsynt, tabrowl, and getrowlin removed from Csound distribution, now
  available from third-party repository.

Utilities

Frontends

General Usage

• Csound no longer supports Python2 opcodes following end of life for Python 2.

Bugs Fixed

• The wterrain2 opcode was not correctly compiled on some platforms.

• fprintks opcode crashed when format contains one %s.

• Bug in rtjack when number of outputs differed from the number in
  inputs.

• FLsetVal now works properly with "inverted range" FLsliders.

• Conditional expressions with a-rate output now work correctly.

• Bug in --opcode-dir option fixed.

• sfpassign failed to remember the number of presets causing
  confusion. This also affects sfplay ad sfinstrplay.

• midiarp opcode fixed (issue 1365).

• A bug in moogladder where the value of 0dbfs affected the output is
  now fixed.

• Bugs in several filters where istor was defaulting to 1 instead of 0
  as described in the manual have been fixed.

• Bug in assigning numbers to named instruments fixed. This
  particularly affected dynamic definitions of instruments.

• Use of %s format in sprintf crashed if the corresponding item was not a
  string. Thus now gives an error.

• Fix bug in ftprint where trigger was not working as advertised.

• Asynchronous use of diskin2 fixed.

• pvs2tab does not crash in the sliding case but gives a error.

• In some circumstances turnoff2 could cause the silencing of another
  instrument for one k-cycle. This is now fixed.

• timeinstk behaved differently in a UDO to normal use. This has been
  corrected.

• Fixed midiarp init method as it was causing an issue with one of the arp modes.

• Fixed scaling of attack stage of xadsr.

• Fix printarray behaviour for string arrays (default is to print at
  every cycle); added a variant without trigger.

• Bug with named instrument merging in new compilations fixed.

• ATSA opcode atsinnoi could cause memory problems. The 6.16 release is better but not yet verified.

SYSTEM LEVEL CHANGES

System Changes

• New autocorrelation routine can compute in the frequency or
  in the time domain. Thanks to Patrick Ropohl for suggesting
  the improvement.

• Minimum cmake version bumped to 3.5.

• Image opcodes removed, now in plugin repo.

• faust opcodes removed, now in plugin repo.

• Python opcodes are now in plugin repo.

• Ableton Link opcodes moved to plugins repo.

Translations

API

Platform Specific

• WebAudio:
  the csound.js frontend is deprecated and no longer distributed. A separate package is not provided here anymore, but new builds will be distributed as NPM modules. A project website repo, https://github.com/csound/webaudio is under development, where we will host the documentation and tutorial sub-site of csound.com for webaudio. This will be the landing page where users go to for information on WebAudio Csound API as well as have examples, links to projects using Csound, etc.

• iOS

• Android

• Windows

• MacOS:

  Some opcode libs with dependencies have been removed from release. Image
  opcodes, Python opcodes, Faust opcodes, and FLTK Widget opcodes have
  been moved to a separate repository and are not included anymore.

• GNU/Linux

• Haiku port

• Bela