some backends can handle incorrectly ordered midi events.

[ardour.git] / libs / backends / alsa / alsa_audiobackend.cc

diff --git a/libs/backends/alsa/alsa_audiobackend.cc b/libs/backends/alsa/alsa_audiobackend.cc
index 3462103023276889e1a9d87b5fd0fc9990484154..8befb9219cadbe91ca4319d31ece8699e2dc21c7 100644 (file)
--- a/libs/backends/alsa/alsa_audiobackend.cc
+++ b/libs/backends/alsa/alsa_audiobackend.cc
@@ -232,7 +232,7 @@ AlsaAudioBackend::can_change_sample_rate_when_running () const
 bool
 AlsaAudioBackend::can_change_buffer_size_when_running () const
 {
-       return false;
+       return false; // why not? :)
 }
 
 int
@@ -257,6 +257,9 @@ AlsaAudioBackend::set_buffer_size (uint32_t bs)
        if (bs <= 0 || bs >= _max_buffer_size) {
                return -1;
        }
+       if (_run) {
+               return -1;
+       }
        _samples_per_period = bs;
        engine.buffer_size_change (bs);
        return 0;
@@ -965,7 +968,7 @@ AlsaAudioBackend::register_system_audio_ports()
        const int a_out = _n_outputs > 0 ? _n_outputs : 2;
 
        /* audio ports */
-       lr.min = lr.max = _samples_per_period + (_measure_latency ? 0 : _systemic_audio_input_latency);
+       lr.min = lr.max = (_measure_latency ? 0 : _systemic_audio_input_latency);
        for (int i = 1; i <= a_ins; ++i) {
                char tmp[64];
                snprintf(tmp, sizeof(tmp), "system:capture_%d", i);
@@ -975,7 +978,7 @@ AlsaAudioBackend::register_system_audio_ports()
                _system_inputs.push_back(static_cast<AlsaPort*>(p));
        }
 
-       lr.min = lr.max = _samples_per_period + (_measure_latency ? 0 : _systemic_audio_output_latency);
+       lr.min = lr.max = (_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);
@@ -1036,7 +1039,7 @@ AlsaAudioBackend::register_system_midi_ports()
                                        delete mout;
                                }
                                LatencyRange lr;
-                               lr.min = lr.max = _samples_per_period + (_measure_latency ? 0 : nfo->systemic_output_latency);
+                               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);
                                _system_midi_out.push_back(static_cast<AlsaPort*>(p));
@@ -1074,7 +1077,7 @@ AlsaAudioBackend::register_system_midi_ports()
                                        continue;
                                }
                                LatencyRange lr;
-                               lr.min = lr.max = _samples_per_period + (_measure_latency ? 0 : nfo->systemic_input_latency);
+                               lr.min = lr.max = (_measure_latency ? 0 : nfo->systemic_input_latency);
                                set_latency_range (p, false, lr);
                                _system_midi_in.push_back(static_cast<AlsaPort*>(p));
                                _rmidi_in.push_back (midin);
@@ -1253,9 +1256,11 @@ AlsaAudioBackend::midi_event_put (
        assert (buffer && port_buffer);
        AlsaMidiBuffer& dst = * static_cast<AlsaMidiBuffer*>(port_buffer);
        if (dst.size () && (pframes_t)dst.back ()->timestamp () > timestamp) {
+#ifndef NDEBUG
+               // nevermind, ::get_buffer() sorts events
                fprintf (stderr, "AlsaMidiBuffer: it's too late for this event. %d > %d\n",
                                (pframes_t)dst.back ()->timestamp (), timestamp);
-               return -1;
+#endif
        }
        dst.push_back (boost::shared_ptr<AlsaMidiEvent>(new AlsaMidiEvent (timestamp, buffer, size)));
        return 0;
@@ -1317,14 +1322,28 @@ AlsaAudioBackend::set_latency_range (PortEngine::PortHandle port, bool for_playb
 LatencyRange
 AlsaAudioBackend::get_latency_range (PortEngine::PortHandle port, bool for_playback)
 {
+       LatencyRange r;
        if (!valid_port (port)) {
                PBD::error << _("AlsaPort::get_latency_range (): invalid port.") << endmsg;
-               LatencyRange r;
                r.min = 0;
                r.max = 0;
                return r;
        }
-       return static_cast<AlsaPort*>(port)->latency_range (for_playback);
+       AlsaPort *p = static_cast<AlsaPort*>(port);
+       assert(p);
+
+       r = p->latency_range (for_playback);
+       if (p->is_physical() && p->is_terminal()) {
+               if (p->is_input() && for_playback) {
+                       r.min += _samples_per_period;
+                       r.max += _samples_per_period;
+               }
+               if (p->is_output() && !for_playback) {
+                       r.min += _samples_per_period;
+                       r.max += _samples_per_period;
+               }
+       }
+       return r;
 }
 
 /* Discovering physical ports */
@@ -1573,7 +1592,7 @@ AlsaAudioBackend::main_process_thread ()
                                rm->sync_time (clock1);
                        }
 
-                       _last_process_start = -1;
+                       _last_process_start = 0;
                        if (engine.process_callback (_samples_per_period)) {
                                _pcmi->pcm_stop ();
                                _active = false;