[PATCH] winealsa.drv: Fix handling of system real time MIDI messages

[Bruno Jesus]

On Tue, Jan 31, 2017 at 1:39 PM, Andrew Eikum <aeikum at codeweavers.com> wrote:
> On Tue, Jan 31, 2017 at 04:16:17AM -0200, Bruno Jesus wrote:
>> MIDI spec at http://www.somascape.org/midi/tech/spec.html state that system real time messages "... are each single byte messages, with no following data bytes...", currently wine is prepending SYSEX header generating invalid messages.
>>
>
> Looking at this spec, should Tune Request be handled the same way as
> these system real time messages? I also noticed Reset is still handled
> as a SysEx after your patch. Should it be?

I'm now using the program SendMIDI [1] to test together with
gmidimonitor to receive the messages. This program has the advantage
that it lets me send manually all sorts of messages.

Tune Request is a one byte system common message like the other system
real time messages, that is why it falls in the same case.

I didn't want to touch the reset message, it is like that since
forever and was based in OSS [2] code added ages ago. According to [3]
the sequence {0xf0, 0x7e, 0x7f, 0x09, 0x01, 0xf7} stands for "GM
System On", seems to be a vendor specific message. But I cannot state
it is right or wrong.

To test all this:
gmidimonitor --alsa &
wine sendmidi.exe dev "MIDI monitor - midi in" start stop cont spp 10
ss 1 tun as clock 100 rst

(clock message will repeat 48 times)

[1] https://github.com/gbevin/SendMIDI
[2] http://source.winehq.org/git/wine.git/commitdiff/d30dfd24#patch172
[3] http://openmidiproject.osdn.jp/documentations_en.html

> Aside from that, I also noticed an old patch that unfortunately never
> got merged:
>
>   https://www.winehq.org/pipermail/wine-patches/2013-January/121366.html
>
> If you understand this MIDI stuff a little bit, you might be a good
> person to review and re-submit that patch :)

The patch makes sense, 0x7F is the sysex terminator (EOX). I'll do
some test to ensure it is correct and resend.

Best wishes,
Bruno