correct name of Midi-UI thread memory-pool and request-queue
[ardour.git] / libs / backends / alsa / alsa_audiobackend.cc
index 1e9ebd77648fb03657da02e3d62c43bdc203d390..725fc80b765c63b9f64340c2afaa3229ec07d72b 100644 (file)
@@ -58,7 +58,7 @@ AlsaAudioBackend::AlsaAudioBackend (AudioEngine& e, AudioBackendInfo& info)
        , _last_process_start (0)
        , _input_audio_device("")
        , _output_audio_device("")
-       , _midi_driver_option(_("None"))
+       , _midi_driver_option(get_standard_device_name(DeviceNone))
        , _device_reservation(0)
        , _samplerate (48000)
        , _samples_per_period (1024)
@@ -69,6 +69,8 @@ AlsaAudioBackend::AlsaAudioBackend (AudioEngine& e, AudioBackendInfo& info)
        , _systemic_audio_output_latency (0)
        , _dsp_load (0)
        , _processed_samples (0)
+       , _midi_ins (0)
+       , _midi_outs (0)
        , _port_change_flag (false)
 {
        _instance_name = s_instance_name;
@@ -116,7 +118,7 @@ AlsaAudioBackend::enumerate_input_devices () const
        _input_audio_device_status.clear();
        std::map<std::string, std::string> devices;
        get_alsa_audio_device_names(devices, HalfDuplexIn);
-       _input_audio_device_status.push_back (DeviceStatus (_("None"), true));
+       _input_audio_device_status.push_back (DeviceStatus (get_standard_device_name(DeviceNone), true));
        for (std::map<std::string, std::string>::const_iterator i = devices.begin (); i != devices.end(); ++i) {
                if (_input_audio_device == "") _input_audio_device = i->first;
                _input_audio_device_status.push_back (DeviceStatus (i->first, true));
@@ -130,7 +132,7 @@ AlsaAudioBackend::enumerate_output_devices () const
        _output_audio_device_status.clear();
        std::map<std::string, std::string> devices;
        get_alsa_audio_device_names(devices, HalfDuplexOut);
-       _output_audio_device_status.push_back (DeviceStatus (_("None"), true));
+       _output_audio_device_status.push_back (DeviceStatus (get_standard_device_name(DeviceNone), true));
        for (std::map<std::string, std::string>::const_iterator i = devices.begin (); i != devices.end(); ++i) {
                if (_output_audio_device == "") _output_audio_device = i->first;
                _output_audio_device_status.push_back (DeviceStatus (i->first, true));
@@ -216,16 +218,16 @@ AlsaAudioBackend::acquire_device(const char* device_name)
 }
 
 std::vector<float>
-AlsaAudioBackend::available_sample_rates (const std::string& input_device, const std::string& output_device) const
+AlsaAudioBackend::available_sample_rates2 (const std::string& input_device, const std::string& output_device) const
 {
        std::vector<float> sr;
-       if (input_device == _("None") && output_device == _("None")) {
+       if (input_device == get_standard_device_name(DeviceNone) && output_device == get_standard_device_name(DeviceNone)) {
                return sr;
        }
-       else if (input_device == _("None")) {
+       else if (input_device == get_standard_device_name(DeviceNone)) {
                sr = available_sample_rates (output_device);
        }
-       else if (output_device == _("None")) {
+       else if (output_device == get_standard_device_name(DeviceNone)) {
                sr = available_sample_rates (input_device);
        } else {
                std::vector<float> sr_in =  available_sample_rates (input_device);
@@ -240,7 +242,7 @@ AlsaAudioBackend::available_sample_rates (const std::string& device) const
 {
        ALSADeviceInfo *nfo = NULL;
        std::vector<float> sr;
-       if (device == _("None")) {
+       if (device == get_standard_device_name(DeviceNone)) {
                return sr;
        }
        if (device == _input_audio_device && _input_audio_device_info.valid) {
@@ -262,16 +264,16 @@ AlsaAudioBackend::available_sample_rates (const std::string& device) const
 }
 
 std::vector<uint32_t>
-AlsaAudioBackend::available_buffer_sizes (const std::string& input_device, const std::string& output_device) const
+AlsaAudioBackend::available_buffer_sizes2 (const std::string& input_device, const std::string& output_device) const
 {
        std::vector<uint32_t> bs;
-       if (input_device == _("None") && output_device == _("None")) {
+       if (input_device == get_standard_device_name(DeviceNone) && output_device == get_standard_device_name(DeviceNone)) {
                return bs;
        }
-       else if (input_device == _("None")) {
+       else if (input_device == get_standard_device_name(DeviceNone)) {
                bs = available_buffer_sizes (output_device);
        }
-       else if (output_device == _("None")) {
+       else if (output_device == get_standard_device_name(DeviceNone)) {
                bs = available_buffer_sizes (input_device);
        } else {
                std::vector<uint32_t> bs_in =  available_buffer_sizes (input_device);
@@ -286,7 +288,7 @@ AlsaAudioBackend::available_buffer_sizes (const std::string& device) const
 {
        ALSADeviceInfo *nfo = NULL;
        std::vector<uint32_t> bs;
-       if (device == _("None")) {
+       if (device == get_standard_device_name(DeviceNone)) {
                return bs;
        }
        if (device == _input_audio_device && _input_audio_device_info.valid) {
@@ -309,7 +311,7 @@ AlsaAudioBackend::available_buffer_sizes (const std::string& device) const
 uint32_t
 AlsaAudioBackend::available_input_channel_count (const std::string& device) const
 {
-       if (device == _("None")) {
+       if (device == get_standard_device_name(DeviceNone)) {
                return 0;
        }
        if (device == _input_audio_device && _input_audio_device_info.valid) {
@@ -321,7 +323,7 @@ AlsaAudioBackend::available_input_channel_count (const std::string& device) cons
 uint32_t
 AlsaAudioBackend::available_output_channel_count (const std::string& device) const
 {
-       if (device == _("None")) {
+       if (device == get_standard_device_name(DeviceNone)) {
                return 0;
        }
        if (device == _output_audio_device && _output_audio_device_info.valid) {
@@ -330,6 +332,15 @@ AlsaAudioBackend::available_output_channel_count (const std::string& device) con
        return 128;
 }
 
+std::vector<uint32_t>
+AlsaAudioBackend::available_period_sizes (const std::string& driver) const
+{
+       std::vector<uint32_t> ps;
+       ps.push_back (2);
+       ps.push_back (3);
+       return ps;
+}
+
 bool
 AlsaAudioBackend::can_change_sample_rate_when_running () const
 {
@@ -350,7 +361,7 @@ AlsaAudioBackend::set_input_device_name (const std::string& d)
        }
        _input_audio_device = d;
 
-       if (d == _("None")) {
+       if (d == get_standard_device_name(DeviceNone)) {
                _input_audio_device_info.valid = false;
                return 0;
        }
@@ -382,7 +393,7 @@ AlsaAudioBackend::set_output_device_name (const std::string& d)
 
        _output_audio_device = d;
 
-       if (d == _("None")) {
+       if (d == get_standard_device_name(DeviceNone)) {
                _output_audio_device_info.valid = false;
                return 0;
        }
@@ -422,6 +433,19 @@ AlsaAudioBackend::set_sample_rate (float sr)
        return 0;
 }
 
+int
+AlsaAudioBackend::set_peridod_size (uint32_t n)
+{
+       if (n == 0 || n > 3) {
+               return -1;
+       }
+       if (_run) {
+               return -1;
+       }
+       _periods_per_cycle = n;
+       return 0;
+}
+
 int
 AlsaAudioBackend::set_buffer_size (uint32_t bs)
 {
@@ -461,6 +485,9 @@ int
 AlsaAudioBackend::set_systemic_input_latency (uint32_t sl)
 {
        _systemic_audio_input_latency = sl;
+       if (_run) {
+               update_systemic_audio_latencies();
+       }
        return 0;
 }
 
@@ -468,6 +495,9 @@ int
 AlsaAudioBackend::set_systemic_output_latency (uint32_t sl)
 {
        _systemic_audio_output_latency = sl;
+       if (_run) {
+               update_systemic_audio_latencies();
+       }
        return 0;
 }
 
@@ -477,6 +507,9 @@ AlsaAudioBackend::set_systemic_midi_input_latency (std::string const device, uin
        struct AlsaMidiDeviceInfo * nfo = midi_device_info(device);
        if (!nfo) return -1;
        nfo->systemic_input_latency = sl;
+       if (_run && nfo->enabled) {
+               update_systemic_midi_latencies ();
+       }
        return 0;
 }
 
@@ -486,17 +519,65 @@ AlsaAudioBackend::set_systemic_midi_output_latency (std::string const device, ui
        struct AlsaMidiDeviceInfo * nfo = midi_device_info(device);
        if (!nfo) return -1;
        nfo->systemic_output_latency = sl;
+       if (_run && nfo->enabled) {
+               update_systemic_midi_latencies ();
+       }
        return 0;
 }
 
+void
+AlsaAudioBackend::update_systemic_audio_latencies ()
+{
+       const uint32_t lcpp = (_periods_per_cycle - 2) * _samples_per_period;
+       LatencyRange lr;
+
+       lr.min = lr.max = lcpp + (_measure_latency ? 0 : _systemic_audio_input_latency);
+       for (std::vector<AlsaPort*>::const_iterator it = _system_outputs.begin (); it != _system_outputs.end (); ++it) {
+               set_latency_range (*it, true, lr);
+       }
+
+       lr.min = lr.max = (_measure_latency ? 0 : _systemic_audio_output_latency);
+       for (std::vector<AlsaPort*>::const_iterator it = _system_inputs.begin (); it != _system_inputs.end (); ++it) {
+               set_latency_range (*it, false, lr);
+       }
+       update_latencies ();
+}
+
+void
+AlsaAudioBackend::update_systemic_midi_latencies ()
+{
+       uint32_t i = 0;
+       for (std::vector<AlsaPort*>::iterator it = _system_midi_out.begin (); it != _system_midi_out.end (); ++it, ++i) {
+               assert (_rmidi_out.size() > i);
+               AlsaMidiOut *rm = _rmidi_out.at(i);
+               struct AlsaMidiDeviceInfo * nfo = midi_device_info (rm->name());
+               assert (nfo);
+               LatencyRange lr;
+               lr.min = lr.max = (_measure_latency ? 0 : nfo->systemic_output_latency);
+               set_latency_range (*it, false, lr);
+       }
+
+       i = 0;
+       for (std::vector<AlsaPort*>::const_iterator it = _system_midi_in.begin (); it != _system_midi_in.end (); ++it, ++i) {
+               assert (_rmidi_in.size() > i);
+               AlsaMidiIO *rm = _rmidi_in.at(i);
+               struct AlsaMidiDeviceInfo * nfo = midi_device_info (rm->name());
+               assert (nfo);
+               LatencyRange lr;
+               lr.min = lr.max = (_measure_latency ? 0 : nfo->systemic_input_latency);
+               set_latency_range (*it, true, lr);
+       }
+       update_latencies ();
+}
+
 /* Retrieving parameters */
 std::string
 AlsaAudioBackend::device_name () const
 {
-       if (_input_audio_device != _("None")) {
+       if (_input_audio_device != get_standard_device_name(DeviceNone)) {
                return _input_audio_device;
        }
-       if (_output_audio_device != _("None")) {
+       if (_output_audio_device != get_standard_device_name(DeviceNone)) {
                return _output_audio_device;
        }
        return "";
@@ -526,6 +607,12 @@ AlsaAudioBackend::buffer_size () const
        return _samples_per_period;
 }
 
+uint32_t
+AlsaAudioBackend::period_size () const
+{
+       return _periods_per_cycle;
+}
+
 bool
 AlsaAudioBackend::interleaved () const
 {
@@ -581,7 +668,7 @@ AlsaAudioBackend::midi_device_info(std::string const name) const {
                }
        }
 
-       assert(_midi_driver_option != _("None"));
+       assert(_midi_driver_option != get_standard_device_name(DeviceNone));
 
        std::map<std::string, std::string> devices;
        if (_midi_driver_option == _("ALSA raw devices")) {
@@ -605,7 +692,7 @@ AlsaAudioBackend::enumerate_midi_options () const
        if (_midi_options.empty()) {
                _midi_options.push_back (_("ALSA raw devices"));
                _midi_options.push_back (_("ALSA sequencer"));
-               _midi_options.push_back (_("None"));
+               _midi_options.push_back (get_standard_device_name(DeviceNone));
        }
        return _midi_options;
 }
@@ -632,7 +719,10 @@ AlsaAudioBackend::enumerate_midi_devices () const
 int
 AlsaAudioBackend::set_midi_option (const std::string& opt)
 {
-       if (opt != _("None") && opt != _("ALSA raw devices") && opt != _("ALSA sequencer")) {
+       if (opt != get_standard_device_name(DeviceNone) && opt != _("ALSA raw devices") && opt != _("ALSA sequencer")) {
+               return -1;
+       }
+       if (_run && _midi_driver_option != opt) {
                return -1;
        }
        _midi_driver_option = opt;
@@ -650,7 +740,41 @@ AlsaAudioBackend::set_midi_device_enabled (std::string const device, bool enable
 {
        struct AlsaMidiDeviceInfo * nfo = midi_device_info(device);
        if (!nfo) return -1;
+       const bool prev_enabled = nfo->enabled;
        nfo->enabled = enable;
+
+       if (_run && prev_enabled != enable) {
+               if (enable) {
+                       // add ports for the given device
+                       register_system_midi_ports(device);
+               } else {
+                       // remove all ports provided by the given device
+                       uint32_t i = 0;
+                       for (std::vector<AlsaPort*>::iterator it = _system_midi_out.begin (); it != _system_midi_out.end ();) {
+                               assert (_rmidi_out.size() > i);
+                               AlsaMidiOut *rm = _rmidi_out.at(i);
+                               if (rm->name () != device) { ++it; ++i; continue; }
+                               it = _system_midi_out.erase (it);
+                               unregister_port (*it);
+                               rm->stop();
+                               _rmidi_out.erase (_rmidi_out.begin() + i);
+                               delete rm;
+                       }
+
+                       i = 0;
+                       for (std::vector<AlsaPort*>::iterator it = _system_midi_in.begin (); it != _system_midi_in.end ();) {
+                               assert (_rmidi_in.size() > i);
+                               AlsaMidiIn *rm = _rmidi_in.at(i);
+                               if (rm->name () != device) { ++it; ++i; continue; }
+                               it = _system_midi_in.erase (it);
+                               unregister_port (*it);
+                               rm->stop();
+                               _rmidi_in.erase (_rmidi_in.begin() + i);
+                               delete rm;
+                       }
+               }
+               update_systemic_midi_latencies ();
+       }
        return 0;
 }
 
@@ -682,7 +806,7 @@ AlsaAudioBackend::_start (bool for_latency_measurement)
 
        if (_active || _run) {
                PBD::error << _("AlsaAudioBackend: already active.") << endmsg;
-               return -1;
+               return BackendReinitializationError;
        }
 
        if (_ports.size()) {
@@ -711,17 +835,17 @@ AlsaAudioBackend::_start (bool for_latency_measurement)
        std::string alsa_device;
        std::map<std::string, std::string> devices;
 
-       if (_input_audio_device == _("None") && _output_audio_device == _("None")) {
+       if (_input_audio_device == get_standard_device_name(DeviceNone) && _output_audio_device == get_standard_device_name(DeviceNone)) {
                PBD::error << _("AlsaAudioBackend: At least one of input or output device needs to be set.");
-               return -1;
+               return AudioDeviceInvalidError;
        }
 
        if (_input_audio_device != _output_audio_device) {
-               if (_input_audio_device != _("None") && _output_audio_device != _("None")) {
+               if (_input_audio_device != get_standard_device_name(DeviceNone) && _output_audio_device != get_standard_device_name(DeviceNone)) {
                        PBD::error << _("AlsaAudioBackend: Cannot use two different devices.");
-                       return -1;
+                       return AudioDeviceInvalidError;
                }
-               if (_input_audio_device != _("None")) {
+               if (_input_audio_device != get_standard_device_name(DeviceNone)) {
                        get_alsa_audio_device_names(devices, HalfDuplexIn);
                        audio_device = _input_audio_device;
                        duplex = 1;
@@ -744,28 +868,59 @@ AlsaAudioBackend::_start (bool for_latency_measurement)
        }
        if (alsa_device == "") {
                PBD::error << _("AlsaAudioBackend: Cannot find configured device. Is it still connected?");
-               return -1;
+               return AudioDeviceNotAvailableError;
        }
 
        acquire_device(alsa_device.c_str());
        _pcmi = new Alsa_pcmi (
                        (duplex & 2) ? alsa_device.c_str() : NULL,
                        (duplex & 1) ? alsa_device.c_str() : NULL,
-                       0, _samplerate, _samples_per_period, _periods_per_cycle, 0);
-       switch (_pcmi->state ()) {
-               case 0: /* OK */ break;
-               case -1: PBD::error << _("AlsaAudioBackend: failed to open device.") << endmsg; break;
-               case -2: PBD::error << _("AlsaAudioBackend: failed to allocate parameters.") << endmsg; break;
-               case -3: PBD::error << _("AlsaAudioBackend: cannot set requested sample rate.") << endmsg; break;
-               case -4: PBD::error << _("AlsaAudioBackend: cannot set requested period size.") << endmsg; break;
-               case -5: PBD::error << _("AlsaAudioBackend: cannot set requested number of periods.") << endmsg; break;
-               case -6: PBD::error << _("AlsaAudioBackend: unsupported sample format.") << endmsg; break;
-               default: PBD::error << _("AlsaAudioBackend: initialization failed.") << endmsg; break;
+                       /* ctrl name */ 0,
+                       _samplerate, _samples_per_period,
+                       _periods_per_cycle, /* _periods_per_cycle */ 2,
+                       /* debug */ 0);
+
+       AudioBackend::ErrorCode error_code = NoError;
+       switch (_pcmi->state()) {
+       case 0: /* OK */
+               break;
+       case -1:
+               PBD::error << _("AlsaAudioBackend: failed to open device.") << endmsg;
+               error_code = AudioDeviceOpenError;
+               break;
+       case -2:
+               PBD::error << _("AlsaAudioBackend: failed to allocate parameters.") << endmsg;
+               error_code = AudioDeviceOpenError;
+               break;
+       case -3:
+               PBD::error << _("AlsaAudioBackend: cannot set requested sample rate.")
+                          << endmsg;
+               error_code = SampleRateNotSupportedError;
+               break;
+       case -4:
+               PBD::error << _("AlsaAudioBackend: cannot set requested period size.")
+                          << endmsg;
+               error_code = PeriodSizeNotSupportedError;
+               break;
+       case -5:
+               PBD::error << _("AlsaAudioBackend: cannot set requested number of periods.")
+                          << endmsg;
+               error_code = PeriodCountNotSupportedError;
+               break;
+       case -6:
+               PBD::error << _("AlsaAudioBackend: unsupported sample format.") << endmsg;
+               error_code = SampleFormatNotSupportedError;
+               break;
+       default:
+               PBD::error << _("AlsaAudioBackend: initialization failed.") << endmsg;
+               error_code = AudioDeviceOpenError;
+               break;
        }
+
        if (_pcmi->state ()) {
                delete _pcmi; _pcmi = 0;
                release_device();
-               return -1;
+               return error_code;
        }
 
 #ifndef NDEBUG
@@ -803,13 +958,14 @@ AlsaAudioBackend::_start (bool for_latency_measurement)
 
        _measure_latency = for_latency_measurement;
 
+       _midi_ins = _midi_outs = 0;
        register_system_midi_ports();
 
        if (register_system_audio_ports()) {
                PBD::error << _("AlsaAudioBackend: failed to register system ports.") << endmsg;
                delete _pcmi; _pcmi = 0;
                release_device();
-               return -1;
+               return PortRegistrationError;
        }
 
        engine.sample_rate_change (_samplerate);
@@ -819,7 +975,7 @@ AlsaAudioBackend::_start (bool for_latency_measurement)
                PBD::error << _("AlsaAudioBackend: Could not re-establish ports.") << endmsg;
                delete _pcmi; _pcmi = 0;
                release_device();
-               return -1;
+               return PortReconnectError;
        }
 
        engine.reconnect_ports ();
@@ -835,7 +991,7 @@ AlsaAudioBackend::_start (bool for_latency_measurement)
                        delete _pcmi; _pcmi = 0;
                        release_device();
                        _run = false;
-                       return -1;
+                       return ProcessThreadStartError;
                } else {
                        PBD::warning << _("AlsaAudioBackend: cannot acquire realtime permissions.") << endmsg;
                }
@@ -849,10 +1005,10 @@ AlsaAudioBackend::_start (bool for_latency_measurement)
                delete _pcmi; _pcmi = 0;
                release_device();
                _run = false;
-               return -1;
+               return ProcessThreadStartError;
        }
 
-       return 0;
+       return NoError;
 }
 
 int
@@ -884,6 +1040,7 @@ AlsaAudioBackend::stop ()
 
        unregister_ports();
        delete _pcmi; _pcmi = 0;
+       _midi_ins = _midi_outs = 0;
        release_device();
 
        return (_active == false) ? 0 : -1;
@@ -899,7 +1056,7 @@ AlsaAudioBackend::freewheel (bool onoff)
 float
 AlsaAudioBackend::dsp_load () const
 {
-       return std::min(100.f, 100.f * _dsp_load);
+       return 100.f * _dsp_load;
 }
 
 size_t
@@ -1180,6 +1337,8 @@ AlsaAudioBackend::register_system_audio_ports()
        const int a_ins = _n_inputs;
        const int a_out = _n_outputs;
 
+       const uint32_t lcpp = (_periods_per_cycle - 2) * _samples_per_period;
+
        /* audio ports */
        lr.min = lr.max = (_measure_latency ? 0 : _systemic_audio_input_latency);
        for (int i = 1; i <= a_ins; ++i) {
@@ -1191,7 +1350,7 @@ AlsaAudioBackend::register_system_audio_ports()
                _system_inputs.push_back(static_cast<AlsaPort*>(p));
        }
 
-       lr.min = lr.max = (_measure_latency ? 0 : _systemic_audio_output_latency);
+       lr.min = lr.max = lcpp + (_measure_latency ? 0 : _systemic_audio_output_latency);
        for (int i = 1; i <= a_out; ++i) {
                char tmp[64];
                snprintf(tmp, sizeof(tmp), "system:playback_%d", i);
@@ -1204,13 +1363,13 @@ AlsaAudioBackend::register_system_audio_ports()
 }
 
 int
-AlsaAudioBackend::register_system_midi_ports()
+AlsaAudioBackend::register_system_midi_ports(const std::string device)
 {
        std::map<std::string, std::string> devices;
-       int midi_ins = 0;
-       int midi_outs = 0;
 
-       if (_midi_driver_option == _("None")) {
+       // TODO use consistent numbering when re-adding devices: _midi_ins, _midi_outs
+
+       if (_midi_driver_option == get_standard_device_name(DeviceNone)) {
                return 0;
        } else if (_midi_driver_option == _("ALSA raw devices")) {
                get_alsa_rawmidi_device_names(devices);
@@ -1219,15 +1378,18 @@ AlsaAudioBackend::register_system_midi_ports()
        }
 
        for (std::map<std::string, std::string>::const_iterator i = devices.begin (); i != devices.end(); ++i) {
+               if (!device.empty() && device != i->first) {
+                       continue;
+               }
                struct AlsaMidiDeviceInfo * nfo = midi_device_info(i->first);
                if (!nfo) continue;
                if (!nfo->enabled) continue;
 
                AlsaMidiOut *mout;
                if (_midi_driver_option == _("ALSA raw devices")) {
-                       mout = new AlsaRawMidiOut (i->second.c_str());
+                       mout = new AlsaRawMidiOut (i->first, i->second.c_str());
                } else {
-                       mout = new AlsaSeqMidiOut (i->second.c_str());
+                       mout = new AlsaSeqMidiOut (i->first, i->second.c_str());
                }
 
                if (mout->state ()) {
@@ -1245,7 +1407,7 @@ AlsaAudioBackend::register_system_midi_ports()
                                delete mout;
                        } else {
                                char tmp[64];
-                               snprintf(tmp, sizeof(tmp), "system:midi_playback_%d", ++midi_ins);
+                               snprintf(tmp, sizeof(tmp), "system:midi_playback_%d", ++_midi_ins);
                                PortHandle p = add_port(std::string(tmp), DataType::MIDI, static_cast<PortFlags>(IsInput | IsPhysical | IsTerminal));
                                if (!p) {
                                        mout->stop();
@@ -1253,8 +1415,8 @@ AlsaAudioBackend::register_system_midi_ports()
                                }
                                LatencyRange lr;
                                lr.min = lr.max = (_measure_latency ? 0 : nfo->systemic_output_latency);
-                               set_latency_range (p, false, lr);
-                               static_cast<AlsaMidiPort*>(p)->set_n_periods(2);
+                               set_latency_range (p, true, lr);
+                               static_cast<AlsaMidiPort*>(p)->set_n_periods(_periods_per_cycle); // TODO check MIDI alignment
                                _system_midi_out.push_back(static_cast<AlsaPort*>(p));
                                _rmidi_out.push_back (mout);
                        }
@@ -1262,9 +1424,9 @@ AlsaAudioBackend::register_system_midi_ports()
 
                AlsaMidiIn *midin;
                if (_midi_driver_option == _("ALSA raw devices")) {
-                       midin = new AlsaRawMidiIn (i->second.c_str());
+                       midin = new AlsaRawMidiIn (i->first, i->second.c_str());
                } else {
-                       midin = new AlsaSeqMidiIn (i->second.c_str());
+                       midin = new AlsaSeqMidiIn (i->first, i->second.c_str());
                }
 
                if (midin->state ()) {
@@ -1282,7 +1444,7 @@ AlsaAudioBackend::register_system_midi_ports()
                                delete midin;
                        } else {
                                char tmp[64];
-                               snprintf(tmp, sizeof(tmp), "system:midi_capture_%d", ++midi_outs);
+                               snprintf(tmp, sizeof(tmp), "system:midi_capture_%d", ++_midi_outs);
                                PortHandle p = add_port(std::string(tmp), DataType::MIDI, static_cast<PortFlags>(IsOutput | IsPhysical | IsTerminal));
                                if (!p) {
                                        midin->stop();
@@ -1653,11 +1815,10 @@ AlsaAudioBackend::main_process_thread ()
        _active = true;
        _processed_samples = 0;
 
-       uint64_t clock1, clock2;
+       uint64_t clock1;
        _pcmi->pcm_start ();
        int no_proc_errors = 0;
        const int bailout = 2 * _samplerate / _samples_per_period;
-       const int64_t nominal_time = 1e6 * _samples_per_period / _samplerate;
 
        manager.registration_callback();
        manager.graph_order_callback();
@@ -1760,17 +1921,10 @@ AlsaAudioBackend::main_process_thread ()
                                nr -= _samples_per_period;
                                _processed_samples += _samples_per_period;
 
-                               /* calculate DSP load */
-                               clock2 = g_get_monotonic_time();
-                               const int64_t elapsed_time = clock2 - clock1;
-                               // low pass filter
-                               const float load = elapsed_time / (float) nominal_time;
-                               if (load > _dsp_load) {
-                                       _dsp_load = load;
-                               } else {
-                                       const float a = .2 * _samples_per_period / _samplerate;
-                                       _dsp_load = _dsp_load + a * (load - _dsp_load) + 1e-12;
-                               }
+                               _dsp_load_calc.set_max_time(_samplerate, _samples_per_period);
+                               _dsp_load_calc.set_start_timestamp_us (clock1);
+                               _dsp_load_calc.set_stop_timestamp_us (g_get_monotonic_time());
+                               _dsp_load = _dsp_load_calc.get_dsp_load ();
                        }
 
                        if (xrun && (_pcmi->capt_xrun() > 0 || _pcmi->play_xrun() > 0)) {