ALSA backend: device detection

diff --git a/libs/backends/alsa/alsa_audiobackend.cc b/libs/backends/alsa/alsa_audiobackend.cc
index ca4fd25c281c868c8a9151c4faf2f7b8f25d5ee0..7ce83ddc40b989cfc722ba004b75d63971811c42 100644 (file)
--- a/libs/backends/alsa/alsa_audiobackend.cc
+++ b/libs/backends/alsa/alsa_audiobackend.cc
@@ -81,10 +81,12 @@ AlsaAudioBackend::enumerate_devices () const
 {
        std::vector<AudioBackend::DeviceStatus> s;
        int cardnum = -1;
+       int device = -1;
        snd_ctl_card_info_t *info;
        snd_ctl_card_info_alloca (&info);
+       snd_pcm_info_t *pcminfo;
+       snd_pcm_info_alloca (&pcminfo);
 
-       // TODO re-use code from libs/backends/jack/jack_utils.cc
        while (snd_card_next (&cardnum) >= 0 && cardnum >= 0) {
                snd_ctl_t *handle;
 
@@ -92,12 +94,32 @@ AlsaAudioBackend::enumerate_devices () const
                devname += PBD::to_string (cardnum, std::dec);
 
                if (snd_ctl_open (&handle, devname.c_str(), 0) >= 0 && snd_ctl_card_info (handle, info) >= 0) {
-                       //string card_name = snd_ctl_card_info_get_name (info);
-                       int device = -1;
-                       if (snd_ctl_pcm_next_device (handle, &device) >= 0 && device >= 0) {
-                               s.push_back (DeviceStatus (devname, true));
+                       if (snd_ctl_card_info (handle, info) < 0) {
+                               continue;
                        }
-                       snd_ctl_close(handle);
+
+                       std::string card_name = snd_ctl_card_info_get_name (info);
+                       devname = "hw:";
+                       devname += snd_ctl_card_info_get_id (info);
+
+                       while (snd_ctl_pcm_next_device (handle, &device) >= 0 && device >= 0) {
+                               snd_pcm_info_set_device (pcminfo, device);
+                               snd_pcm_info_set_subdevice (pcminfo, 0);
+                               snd_pcm_info_set_stream (pcminfo, SND_PCM_STREAM_CAPTURE);
+                               if (snd_ctl_pcm_info (handle, pcminfo) < 0) {
+                                       continue;
+                               }
+                               snd_pcm_info_set_device (pcminfo, device);
+                               snd_pcm_info_set_subdevice (pcminfo, 0);
+                               snd_pcm_info_set_stream (pcminfo, SND_PCM_STREAM_PLAYBACK);
+                               if (snd_ctl_pcm_info (handle, pcminfo) < 0) {
+                                       continue;
+                               }
+                               devname += ',';
+                               devname += PBD::to_string (device, std::dec);
+                               s.push_back (DeviceStatus (devname + " " + card_name, true));
+                       }
+                       snd_ctl_close (handle);
                }
        }
        return s;
@@ -276,18 +298,82 @@ void
 AlsaAudioBackend::enumerate_midi_devices (std::vector<std::string> &m) const
 {
        int cardnum = -1;
+       snd_ctl_card_info_t *cinfo;
+       snd_ctl_card_info_alloca (&cinfo);
        while (snd_card_next (&cardnum) >= 0 && cardnum >= 0) {
                snd_ctl_t *handle;
                std::string devname = "hw:";
                devname += PBD::to_string (cardnum, std::dec);
-
-               if (snd_ctl_open (&handle, devname.c_str(), 0) >= 0) {
+               if (snd_ctl_open (&handle, devname.c_str (), 0) >= 0 && snd_ctl_card_info (handle, cinfo) >= 0) {
                        int device = -1;
-                       // TODO iterate over sub-devices
-                       if (snd_ctl_rawmidi_next_device (handle, &device) >= 0 && device >= 0) {
-                               m.push_back (devname);
+                       while (snd_ctl_rawmidi_next_device (handle, &device) >= 0 && device >= 0) {
+                               snd_rawmidi_info_t *info;
+                               snd_rawmidi_info_alloca (&info);
+                               snd_rawmidi_info_set_device (info, device);
+
+                               int subs_in, subs_out;
+
+                               snd_rawmidi_info_set_stream (info, SND_RAWMIDI_STREAM_INPUT);
+                               if (snd_ctl_rawmidi_info (handle, info) >= 0) {
+                                       subs_in = snd_rawmidi_info_get_subdevices_count (info);
+                               } else {
+                                       subs_in = 0;
+                               }
+
+                               snd_rawmidi_info_set_stream (info, SND_RAWMIDI_STREAM_OUTPUT);
+                               if (snd_ctl_rawmidi_info (handle, info) >= 0) {
+                                       subs_out = snd_rawmidi_info_get_subdevices_count (info);
+                               } else {
+                                       subs_out = 0;
+                               }
+
+                               const int subs = subs_in > subs_out ? subs_in : subs_out;
+                               if (!subs) {
+                                       continue;
+                               }
+
+                               for (int sub = 0; sub < subs; ++sub) {
+                                       snd_rawmidi_info_set_stream (info, sub < subs_in ?
+                                                       SND_RAWMIDI_STREAM_INPUT :
+                                                       SND_RAWMIDI_STREAM_OUTPUT);
+
+                                       snd_rawmidi_info_set_subdevice (info, sub);
+                                       if (snd_ctl_rawmidi_info (handle, info) < 0) {
+                                               continue;
+                                       }
+
+                                       const char *sub_name = snd_rawmidi_info_get_subdevice_name (info);
+                                       if (sub == 0 && sub_name[0] == '\0') {
+                                               devname = "hw:";
+                                               devname += snd_ctl_card_info_get_id (cinfo);
+                                               devname += ",";
+                                               devname += PBD::to_string (device, std::dec);
+                                               devname += " ";
+                                               devname += snd_rawmidi_info_get_name (info);
+                                               devname += " (";
+                                               if (sub < subs_in) devname += "I";
+                                               if (sub < subs_out) devname += "O";
+                                               devname += ")";
+                                               m.push_back (devname);
+                                               break;
+                                       } else {
+                                               devname = "hw:";
+                                               devname += snd_ctl_card_info_get_id (cinfo);
+                                               devname += ",";
+                                               devname += PBD::to_string (device, std::dec);
+                                               devname += ",";
+                                               devname += PBD::to_string (sub, std::dec);
+                                               devname += " ";
+                                               devname += sub_name;
+                                               devname += " (";
+                                               if (sub < subs_in) devname += "I";
+                                               if (sub < subs_out) devname += "O";
+                                               devname += ")";
+                                               m.push_back (devname);
+                                       }
+                               }
                        }
-                       snd_ctl_close(handle);
+                       snd_ctl_close (handle);
                }
        }
 }
@@ -348,8 +434,10 @@ AlsaAudioBackend::_start (bool for_latency_measurement)
        assert(_rmidi_out.size() == 0);
        assert(_pcmi == 0);
 
-  _pcmi = new Alsa_pcmi (_capture_device.c_str(), _playback_device.c_str(), 0, _samplerate, _samples_per_period, _periods_per_cycle, 0);
+       unsigned int pos = _capture_device.find(" ");
+       _pcmi = new Alsa_pcmi (_capture_device.substr(0, pos).c_str(), _playback_device.substr(0, pos).c_str(), 0, _samplerate, _samples_per_period, _periods_per_cycle, 0);
        if (_pcmi->state ()) {
+               // TODO get detailed error from _pcmi
                PBD::error << _("AlsaAudioBackend: failed to open device (see stderr for details).") << endmsg;
                delete _pcmi; _pcmi = 0;
                return -1;
@@ -780,7 +868,8 @@ AlsaAudioBackend::register_system_midi_ports()
        else if (_midi_device == _("-All-")) {
                enumerate_midi_devices(devices);
        } else {
-               devices.push_back(_midi_device);
+               unsigned int pos = _midi_device.find(" ");
+               devices.push_back(_midi_device.substr(0, pos));
        }
 
        for (std::vector<std::string>::const_iterator i = devices.begin (); i != devices.end (); ++i) {