MIDI

[Marek Peca]

Je to tady, jenom jsem slepej:

1) Tempo

FF 51 03 tt tt tt

Indicates a tempo change. The 3 data bytes of tt tt tt are the tempo
in microseconds per quarter note.

2) Time Signature

FF 58 04 nn dd cc bb

Time signature is expressed as 4 numbers. nn and dd represent the
"numerator" and "denominator" of the signature as notated on sheet
music. The denominator is a negative power of 2: 2 = quarter note, 3
= eighth, etc. The cc expresses the number of MIDI clocks in a
metronome click. The bb parameter expresses the number of notated
32nd notes in a MIDI quarter note (24 MIDI clocks). This event allows
a program to relate what MIDI thinks of as a quarter, to something
entirely different. For example, 6/8 time with a metronome click
every 3 eighth notes and 24 clocks per quarter note would be the
following event:

FF 58 04 06 03 18 08

Jasne, takze konkretni casovy udaj musite vypocitat z tttttt a cc.
(pocet_us_za_jednotku = tttttt/cc)

S MIDI je ale jinak krasa delat, uz se mi po tom stejska :)
Delal jsem sqelej 32kanalovej MIDI-kontroler s AT89C2051, kterej
misto A/D prevodniku pouzival vestavenej komparator a logaritmicky
potenciometry na dorovnani RC exponencialy.

Ale je to masakr, kdyz krome vlastnich dat zpracovavate jeste
prichozi odjinud, musi se davat bacha na pripadne vkladani
prikazovejch bajtu a taky na preteceni vyrovnavaci pameti.


Pekny vecer,
Marek P.