abcmidi: update to 20211015

September 15 2021

abc2midi bug:
The last fix in June 27 2021 inserting a break introduced a new bug.
The chord associated with the 'b' gchord code was missing. b and f
codes were indistinguishable. Fix: removed the break in the switch
statement for case b:

October 11 2021

abc2midi new feature:
In compliance with the ABC draft standard 2.2, I introduced additional
K: and V: options for transposition. You can now indicate the number
of semitones to transpose by giving the original note and the
corresponding transposed note in the K: or V: field using either
shift = note1note2
sound = note1note2
instrument = note1/note2
The number of semitones is determined by the difference note2 - note1.

Abcm2ps and abc2svg recognize this command, but abc2abc, yaps, and
abcmatch ignore this new option.

http://abcnotation.com/wiki/abc:standard:v2.2#transposition

October 15 2021

Abc2abc -P bug

X:1
T: P bug
M:4/4
L:1/4
V:1 clef=treble
V:2 clef=bass
%%staves [1 2]
K:C
V:1
C2 D2  |  C4 |
V:2
C,2 G,2 | C,4|

The command
abc2abc t.abc -t 3 -P 1
fails to transpose voice 1

This bug has been around since this option was introduced in June 7 2011.
Fortunately, it has not bothered anyone until recently.
If you add another K:c after the first V:1 command in the body as
shown below.

X:1
T: P bug
M:4/4
L:1/4
V:1 clef=treble
V:2 clef=bass
%%staves [1 2]
K:C
V:1
K:C
C2 D2  |  C4 |
V:2
C,2 G,2 | C,4|

then voice 1 will be transposed correctly. Unfortunately, there is
no easy fix. When the -P option is present, abc2abc ignores the
first K: field command. (In toabc.c line 1643 event_key aborts
prior to setting up the arrays for a key transpose. Commenting
out this return statement introduces another problem.)

The main issue is that abc2abc only does one pass through the
input file. It does not know whether there is a K: field command
following V:1. If it assumes that there is none and forces a
call to event_key in event_voice, there may be another problem
when a different K: field command is found eventually. I have
decided to suspend support to the -P option because it would be
too complicated to fix this.


(nia)