There isn't any program to generate midi maps, so you will have to edit a file by hand (using your favorite text editor).
A Midi map is a text file that keeps all the needed translations there will be made when playing music.
It consist of four sections: PATCHMAP
,
KEYMAP
, CHANNELMAP
and
OPTIONS
.
Each section must appear only once, except the KEYMAP
section
that can appear as many times as needed, provided that each appearance use a
different TextID (continue reading for details).
The general structure of a map file is:
DEFINE PATCHMAP ... END DEFINE KEYMAP "Name of Keymap" ... END DEFINE KEYMAP "Another Keymap" ... END DEFINE CHANNELMAP ... END OPTIONS ... END
You can see that the DEFINE
word is used to specify
which section is going to be started (except for
OPTIONS
), and END
is put at the
end of each section.
You can put comments by starting the line with a
#
character.
Please, don't forget to send me your map file by email, so that future releases of TDEMid will include support for more non General Midi compliant keyboards.
This section is used to specify how patches are going to be mapped, from GM to your keyboard specs . The general usage is:
(Name of GM Patch name)=(N
) [AllKeysTo M]
Where N
is the number that you keyboard needs to
receive to change the patch to the same that the GM standard does .
Please note that the left side of the equal sign is ignored, so GM patches are supposed to be in order (from 0 to 127) , and so you are not allowed to change the order of the lines nor to omit any of the 128 instruments.
The optional AllKeysTo M
is used to map all notes
that use that instrument to the M
key . For example,
suppose that your midi keyboard doesn't have a Gun Shot sound (GM patch
127) so you want to map it to a percussion drum (i.e. key 60), which
sounds similar to a gun shot, then you can put in the 127th line of the
PATCHMAP
section:
Gunshot =100 AllKeysTo 60
So when a midi file tries to play a note with the patch 127 (gun shot), it will be mapped to the patch 100 (your keyboard's percussion patch) and play the note 60 (independently of the key that was going to be played).
Please note that when I use the expression “Percussion patch”, I mean the patch in which each key plays a different drum, cymbal, tom, maracas and so on, and not to a possible sound which some keyboards have and which plays a different tone of the same drum with each key.
The KEYMAP
section is used to specify how keys are
going to be mapped, within a given channel or instrument . The usage is:
DEFINE KEYMAP "Name of Keymap" C 0 =0 C#0 =1 D 0 =2 ... END
As with the PATCHMAP
section, it is very important
the order of the lines, and that they are all there (the 128 keys).
As you can define multiple keymaps for different channels and instruments, you must give a different name to each one in the first line.
Keymaps are mainly used to map keys in the percussion channel . Have a look at the distributed maps to see some examples.
This section can be used to map some channels to different ones . For
example, if you want to swap the first and second channels, you can
easily do it within the CHANNELMAP
section.
However it is more useful for keyboards that need the percussion channel to be in a given channel (the GM standard use the channel 10, others use the channel 16 and others use channel 9).
Note that midi devices use 16 channels, so the CHANNELMAP
section, has 16 lines, from 0 to 15 , as this one:
(N) = (M) [Keymap "Name"] [ForcePatch x]
Where N
is the channel which is mapped to the
M
channel . If the Keymap
option
is used, the Keymap with name Name
will be used in
this channel (this Keymap should be defined earlier in the map file !) .
If the ForcePatch
option is used, all events that try
to change the patch which is used in this channel will be ignored, and
patch x
will be used instead.
The ForcePatch
option may be useful for example to
always use the percussion patch on the percussion channel.
The OPTIONS
section has some general options that can
be very useful:
OPTIONS PitchBenderRatio = r MapExpressionToVolumeEvents END
You can specify both options, only one, or none of them.
The PitchBenderRatio r
value, has the ratio by which
pitch bender events will be multiplied . That is, when a midi file tries
to send a pitch bender event with a n
value, the real
value that will be sent is n*(r/4096)
(the
4096
value is for not having to put decimal points in
the map file).
This is used because the GM standard says that when a midi keyboard receives a Pitch Bender event with a 4096 data value, it should bend the note to a higher one , but some midi keyboards try to bend the initial note by two or more higher notes (even an octave higher!) when they receive a 4096 . This can be easily fixed by trying different values so that instead of sending a 4096, KMid sends the appropriate value.
When the MapExpressionToVolumeEvents
option is set in
the map file, and a midi file try to send an expression event, KMid will
send a volume event which is understood by more non-GM keyboards, and
which has a similar effect . There are many midi files which use
expression events to fade out at the end of a song, so if you feel that
music should be heard softer and softer, you can turn on this option and
see if this is what you need, because your midi synthesizer could be
ignoring the expression events because it doesn't understand them.
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