Re: Rawmidi bug or missed feature?

[Peter Enderborg <pme@ufh.se>]

Roger E Critchlow Jr wrote:

> Peter Enderborg writes:
>  > Jaroslav Kysela wrote:
>  >
>  > > On Fri, 1 Mar 2002, Peter Enderborg wrote:
>  > >
>  > > > Paul Davis wrote:
>  > > >
>  > > > > >Yes! And the device that is using running status is alsa rawmidi device.
>  > > > >
>  > > > > What makes you think that? AFAIK, the raw MIDI device code does no
>  > > > > parsing of MIDI data at all ...
>  > > >
>  > > > Parsing? It sends raw midi on a stream. That stream is _from_ alsa seq.
>  > > > It is doing the bandwith optimize by it self. I do the parsing.
>  > >
>  > > Ok, please, specify your problem in a more detailed way. At least, we need
>  > > to know about midi paths in your applications and what sequencer clients
>  > > are involved to help you. And yes, there could be a problem with running
>  > > status, because our converts work with it.
>  > >
>  >
>  > I don't know how to be more specific. I have a program that listen to a raw midi
>  >
>  > stream generated by alsa. But I try.
>  >
>  > I have a midisport 8x8. It have a serial port. I have a computer linux. Alsa
>  > don't have
>  > driver for the unit. So I have writen a daemon that open the snd-card-virmidi
>  > with
>  > snd_rawmidi_open(). I have also writen a processor that handels event on a
>  > sequencer level
>  > to interface my Roland MCR-8 with varius applications, synths. Roland MCR-8 a
>  > "multicontroler"
>  > but it is not progammable. It have 9 knobs,9 slides a lot of buttons an a dialer
>  > wheel.
>  > But not all apps have the same mapping of events.  So the processor mapps them i
>  > the way I like
>  > to have them. But it is only control messages.  On the daemon side that
>  > interfaces to the
>  > raw midi stream in encapsulate them in to midimans format and sent them over the
>  > serial port
>  > to the unit. The unit is decapsulate them and send it to the right midi port.
>  > But when I open the
>  > virmidi device in raw mode. I is already assuming that I know what was the last
>  > command. In my case
>  > a control message.  Is this clear enougth? I know that this a very common midi
>  > problem, but it should not have to be a problem within the same machine.
>  >
>
> I think you want to do this differently.
>
> Your program for patching the midisport into the alsa sequencer
> should connect to the midisport driver on one side and the sequencer
> event interface on the other side and use the alsa/snd_midi_event.h
> routines to translate between the two.
>
> So, as you read raw midi bytes from the midisport driver, use
>
>     /* encode from byte stream -
>        return number of written bytes if success */
>     long snd_midi_event_encode(snd_midi_event_t *dev,
>                                unsigned char *buf,
>                                long count,
>                                snd_seq_event_t *ev);
>
> to encode the incoming byte stream into snd_seq_event_t and send the
> events the sequencer using the event interface.
>
> As you receive events from the sequencer, use
>
>    /* decode from event to bytes -
>       return number of written bytes if success */
>    long snd_midi_event_decode(snd_midi_event_t *dev,
>                               unsigned char *buf,
>                               long count,
>                               snd_seq_event_t *ev);
>
> to decode the incoming event stream into a midi byte stream which you
> can then write() to the midisport.
>
> You will need to send a reset on the midisport side when you first
> connect to get the snd_midi_event_t state synchronized to the incoming
> running status.
>
> But you won't see any running status from the alsa side because the
> event interface fully identifies each event.  snd_midi_event_decode
> will use running status on the decode side, but the stream generated
> will start from the first event decoded.
>
> Does this help?
>

Well. I guess it do. I will give it a try. It should work.  What about non midi
snd_seq_event_t.
The internal alsa stuff, like subscribe?

>
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>
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