Datasheet
VS1053b Datasheet
8 SUPPORTED AUDIO DECODER FORMATS
8.9 Supported MIDI Formats
General MIDI and SP-MIDI format 0 files are played. Format 1 and 2 files must be converted to
format 0 by the user. The maximum polyphony is 64, the maximum sustained polyphony is 40.
Actual polyphony depends on the internal clock rate (which is user-selectable), the instruments
used, whether the reverb effect is enabled, and the possible global postprocessing effects en-
abled, such as bass enhancer, treble control or EarSpeaker spatial processing. The polyphony
restriction algorithm makes use of the SP-MIDI MIP table, if present, and uses smooth note
removal.
43 MHz (3.5× input clock) achieves 19-31 simultaneous sustained notes. The instantaneous
amount of notes can be larger. This is a fair compromise between power consumption and
quality, but higher clocks can be used to increase polyphony.
Reverb effect can be controlled by the user. In addition to reverb automatic and reverb off
modes, 14 different decay times can be selected. These roughly correspond to different room
sizes. Also, each midi song decides how much effect each instrument gets. Because the reverb
effect uses about 4 MHz of processing power the automatic control enables reverb only when
the internal clock is at least 3.0×.
In VS1053b both EarSpeaker and MIDI reverb can be on simultaneously. This is ideal for
listening MIDI songs with headphones.
New instruments have been implemented in addition to the 36 that are available in VS1003.
VS1053b now has unique instruments in the whole GM1 instrument set and one bank of GM2
percussions.
Supported MIDI messages:
• meta: 0x51 : set tempo
• other meta: MidiMeta() called
• device control: 0x01 : master volume
• channel message: 0x80 note off, 0x90 note on, 0xc0 program, 0xe0 pitch wheel
• channel message 0xb0: parameter
– 0x00: bank select (0 is default, 0x78 and 0x7f is drums, 0x79 melodic)
– 0x06: RPN MSB: 0 = bend range, 2 = coarse tune
– 0x07: channel volume
– 0x0a: pan control
– 0x0b: expression (changes volume)
– 0x0c: effect control 1 (sets global reverb decay)
– 0x26: RPN LSB: 0 = bend range
– 0x40: hold1
– 0x42: sustenuto
– 0x5b effects level (channel reverb level)
– 0x62,0x63,0x64,0x65: NRPN and RPN selects
– 0x78: all sound off
– 0x79: reset all controllers
– 0x7b, 0x7c, 0x7d: all notes off
Version: 1.22, 2014-12-19 31