linuxaudio.org

On Friday 06 January 2012, you wrote:

quoted text
> 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/acon...

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 it(m_Client->getAvailableOutputs());

    while(it.hasNext()) {

        PortInfo p = it.next();

        cout << p.getClientName() << ":" << p.getPort();

    }
See Drumstick's example "drumgrid":

http://drumstick.sourceforge.net/docs/drumgrid.cpp-example.html
Regards,

Pedro

_______________________________________________

Linux-audio-dev mailing list

Linux-audio-dev@lists.linuxaudio.org

http://lists.linuxaudio.org/listinfo/linux-audio-dev