TC-Helicon VoiceLive Sysex Manual - Manual (Page 4)

Page 4
TC-Helicon Vocal Technologies
www.tc-helicon.com
* Custom Correction Scale:
A correction scale is represented internally as 12 x 8 bit values
packed into 4 x 24 bit words (see the VoiceLive manual for a detailed
description).
Example: Major Scale
Chromatic semitones present: 0, 2, 4, 5, 7, 9, 11 (note count = 7)
12 x 8 bit values: 0, 2, 4, 5, 7, 9, 11, 0, 0, 0, 0, 0 (appended with
zeros)
At this point an offset of 0x32 is applied to each value for internal
purposes. The values are then grouped into 24-bit words.
(0x32, 0x34, 0x36) (0x37, 0x39, 0x3B) (0x43, 0x00, 0x00) (0x00, 0x00,
0x00)
4 x 24 bit words:
word1: 00110010 00110100 00110110 = 0x323436
word2: 00110111 00111001 00111011 = 0x37393B
word3: 10000011 00000000 00000000 = 0x430000
word4: 00000000 00000000 00000000 = 0x000000
Finally, the SYSEX data is created by packing each word into 4 x 7 bit
values as described in the
data packing description. (This system is
used so that in the future software updates, it might be possible to
specify scales with more than 16 pitch divisions per octave).
** Custom Shift maps:
Shift maps are represented internally as 4 sets of 12 values (see the
VoiceLive manual for a detailed description). Each value specifies the
shift amount for its position in the chromatic scale. For example, a
shift map causing an upward major 3
rd interval for all chromatic input
notes would be 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3. A unison map would
be 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0. Shift entries can also be
negative for downward shifts.
For the purpose of storing and dumping, the 12 bytes are packed into 4
x 24-bit values each holding 3 bytes. An offset of (0x32) is applied to
each value before grouping them into 4 x 24 bit words. The SYSEX data
within a preset dump is finally created by packing these 24-bit words
into 7 bit bytes using the
data packing scheme. Since there are 4
voices on the VoiceLive, there are 4 custom shift maps making for 4x16
bytes of SYSEX data.
Parameter data – 0x
22 :
<Data> is 4 bytes. The first two bytes identify the parameter (group
and parameter ID). The last two bytes determine the value of the
parameter represented as a 14 bit 2’s complement signed value. If a
value exceeds the limits of the parameter, the value will be
automatically limited.
Example of 14 bit 2’s complement calculations: