On 06-01-12 11:21, Pedro Lopez-Cabanillas wrote:
On Friday 06 January 2012, you wrote:
btw: is there a way to list available clients/ports from the api.
I know that aconnect -i / -o does this, but is there a c/c++ function?

Dave
The functions are: snd_seq_query_next_client() and snd_seq_query_next_port();
you need to loop calling these functions while they return a correct answer.
For instance, this is the relevant code in "aconnect.c" :

static void do_search_port(snd_seq_t *seq, int perm, action_func_t do_action)
{
       snd_seq_client_info_t *cinfo;
       snd_seq_port_info_t *pinfo;
       int count;

       snd_seq_client_info_alloca(&cinfo);
       snd_seq_port_info_alloca(&pinfo);
       snd_seq_client_info_set_client(cinfo, -1);
       while (snd_seq_query_next_client(seq, cinfo)>= 0) {
             /* reset query info */
             snd_seq_port_info_set_client(pinfo,
snd_seq_client_info_get_client(cinfo));
             snd_seq_port_info_set_port(pinfo, -1);
             count = 0;
             while (snd_seq_query_next_port(seq, pinfo)>= 0) {
                   if (check_permission(pinfo, perm)) {
                         do_action(seq, cinfo, pinfo, count);
                         count++;
                   }
             }
       }
}

See:
http://git.alsa-project.org/?p=alsa-utils.git;a=blob;f=seq/aconnect/aconnect.c
I guess you already know the reference documentation site:
http://www.alsa-project.org/alsa-doc/alsa-lib/seq.html

Just for comparison, a similar enumeration using Drumstick looks like this:

     QListIterator<PortInfo>  it(m_Client->getAvailableOutputs());
     while(it.hasNext()) {
         PortInfo p = it.next();
         cout<<  p.getClientName()<<  ":"<<  p.getPort();
     }
Thanks,

I was thinking that maybe it would be nicer to connect from my program to Hydrogen.
Then I don't have to restart Hydrogen everytime my program has ended.

See Drumstick's example "drumgrid":
http://drumstick.sourceforge.net/docs/drumgrid.cpp-example.html

Regards,
Pedro
Dave
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