sequencer filter client

sequencer filter client

[Garett Shulman]

Hello, I am trying to create a very simple midi filter client for the 
alsa sequencer based on aseqview-0.1.4. I have alsa 0.9.8. This code 
shows the input and the output port in aconnect when executed. And, when 
the raw_midi client is connected The callback does get called when I 
play keys on my piano. However, Its as though the message is getting 
sent back to this client and  not on to the next client. The 
process_event function keeps getting called over and over again with the 
same message when I hit one piano key. It's as though it is sending 
itself the message. Any Ideas are greatly appreciated. -Garett

#include "portlib.h"

int process_event(port_t *p, int type, snd_seq_event_t *ev, int 
*priate_data)
{
    port_write_event(p, ev, 0);
}

int main()
{
        unsigned int caps = SND_SEQ_PORT_CAP_WRITE | 
SND_SEQ_PORT_CAP_SUBS_WRITE | SND_SEQ_PORT_CAP_READ | 
SND_SEQ_PORT_CAP_SUBS_READ;

        port_client_t *client = port_client_new("MIDI filter", 
SND_SEQ_OPEN_DUPLEX);
        port_t *port = port_attach(client, "FILTER port", caps, 
SND_SEQ_PORT_TYPE_MIDI_GENERIC);
        int *priv_data;

        /* add callback */
        port_add_callback(port, PORT_MIDI_EVENT_CB, 
(port_callback_t)process_event, priv_data);

        port_client_do_loop(client);

        return port_detach(port);
}


-------------------------------------------------------
The SF.Net email is sponsored by EclipseCon 2004
Premiere Conference on Open Tools Development and Integration
See the breadth of Eclipse activity. February 3-5 in Anaheim, CA.
http://www.eclipsecon.org/osdn

Re: sequencer filter client

[Clemens Ladisch]

Garett Shulman wrote:
> Hello, I am trying to create a very simple midi filter client for the
> alsa sequencer based on aseqview-0.1.4. I have alsa 0.9.8. This code
> shows the input and the output port in aconnect when executed. And, when
> the raw_midi client is connected The callback does get called when I
> play keys on my piano. However, Its as though the message is getting
> sent back to this client and  not on to the next client.
>
> int process_event(port_t *p, int type, snd_seq_event_t *ev, int *priate_data)
> {
>     port_write_event(p, ev, 0);
> }

The event will be sent to the destination as specified in ev->dest.
For events you have just received, the destination is your own
client/port.

Call snd_seq_ev_set_source(ev, ?) to set your source port, and call
snd_seq_ev_set_subs(ev) to specify that the event is to be sent to all
ports subscribed to your port.


HTH
Clemens




-------------------------------------------------------
The SF.Net email is sponsored by EclipseCon 2004
Premiere Conference on Open Tools Development and Integration
See the breadth of Eclipse activity. February 3-5 in Anaheim, CA.
http://www.eclipsecon.org/osdn

Re: sequencer filter client

[Garett Shulman]

Clemens Ladisch wrote:

>Garett Shulman wrote:
>  
>
>>Hello, I am trying to create a very simple midi filter client for the
>>alsa sequencer based on aseqview-0.1.4. I have alsa 0.9.8. This code
>>shows the input and the output port in aconnect when executed. And, when
>>the raw_midi client is connected The callback does get called when I
>>play keys on my piano. However, Its as though the message is getting
>>sent back to this client and  not on to the next client.
>>
>>int process_event(port_t *p, int type, snd_seq_event_t *ev, int *priate_data)
>>{
>>    port_write_event(p, ev, 0);
>>}
>>    
>>
>
>The event will be sent to the destination as specified in ev->dest.
>For events you have just received, the destination is your own
>client/port.
>
>Call snd_seq_ev_set_source(ev, ?) to set your source port, and call
>snd_seq_ev_set_subs(ev) to specify that the event is to be sent to all
>ports subscribed to your port.
>
>
>HTH
>Clemens
>
>  
>
This does help. Thank you. -Garett


-------------------------------------------------------
The SF.Net email is sponsored by EclipseCon 2004
Premiere Conference on Open Tools Development and Integration
See the breadth of Eclipse activity. February 3-5 in Anaheim, CA.
http://www.eclipsecon.org/osdn