[linux-audio-user] MIDI app??

[Chris Cannam]

Nathaniel Virgo wrote:
> On Monday 03 February 2003 1:43 pm, Joe Hartley wrote:
>>According to the manual, the SysEx header stuff is in place, but
>>od -xc shows me something else - the first 32 bytes are:
>>
>>0000000 544d 6468 0000 0600 0000 0100 6000 544d
>>          M   T   h   d  \0  \0  \0 006  \0  \0  \0 001  \0   `   M   T
>>0000020 6b72 0000 760d f000 729a 0100 1126 0007
>>          r   k  \0  \0  \r   v  \0   ð 232   r  \0 001   & 021  \a  \0
> 
> Maybe it's some kind of header in the midi file?

Yes, a standard MIDI file always starts with MThd then ten bytes
of header data (generally 0x0 0x0 0x0 0x6 then a two-byte format
field, two-byte number-of-tracks field and two-byte timing division
field).  Then each track starts with MTrk and the number of bytes
in the track.  None of this stuff, obviously, is part of the MIDI
wire protocol.  (The file format also may contain file meta-events
such as tempo, time and key signature, lyric and copyright events
etc which are also not part of the wire protocol.  They happen to
share the event code 0xFF with the system-reset event of the wire
protocol, so you definitely shouldn't be sending them to devices.)


Chris