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Alsa Sequencer Tests

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This commit is contained in:
Robin E. R. Davies
2025-06-27 14:24:58 -04:00
parent f0628c2cce
commit acb668853b
17 changed files with 754 additions and 98 deletions
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PiPedalCommon/src/AlsaSequencer.cpp
+140 -70
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@@ -24,6 +24,7 @@
#include "AlsaSequencer.hpp"
#include <vector>
#include <string>
#include <regex>
#include "ss.hpp"
// enumerate alsa sequencer ports
@@ -35,7 +36,7 @@ namespace pipedal
std::vector<AlsaSequencerPort> ports;
snd_seq_t *seq;
if (snd_seq_open(&seq, "default", SND_SEQ_OPEN_INPUT, 0) < 0)
if (snd_seq_open(&seq, "default", SND_SEQ_OPEN_DUPLEX, 0) < 0)
{
return ports;
}
@@ -83,7 +84,7 @@ namespace pipedal
auto typeBits = snd_seq_port_info_get_type(port_info);
#ifdef SND_SEQ_PORT_TYPE_MIDI_UMP
port.isUmp = (typeBits & SND_SEQ_PORT_TYPE_MIDI_UMP) != 0;
#else
#else
port.isUmp = false; // UMP support is not available in all versions of ALSA
#endif
port.isSystemAnnounce = (typeBits & SND_SEQ_PORT_SYSTEM_ANNOUNCE) != 0;
@@ -95,19 +96,52 @@ namespace pipedal
port.isSpecific = (typeBits & SND_SEQ_PORT_TYPE_SPECIFIC) != 0;
port.isSynth = (typeBits & SND_SEQ_PORT_TYPE_SYNTH) != 0;
port.isHardware = (typeBits & SND_SEQ_PORT_TYPE_HARDWARE) != 0;
port.isPort = (typeBits & SND_SEQ_PORT_TYPE_PORT) != 0;
port.isSoftware = (typeBits & SND_SEQ_PORT_TYPE_SOFTWARE) != 0;
port.isVirtual = port.name.starts_with("VirMIDI");
port.cardNumber = snd_seq_client_info_get_card(client_info);
port.port = snd_seq_port_info_get_port(port_info);
if (port.isKernelDevice & port.cardNumber >= 0 && port.port >= 0)
if (port.isKernelDevice && port.isPort && port.cardNumber >= 0 && port.port >= 0)
{
// For kernel devices, we can construct a raw MIDI device string
port.rawMidiDevice = SS("hw:" << port.cardNumber << ",0," << port.port);
std::string rawMidiDevice;
if (port.isVirtual)
{
// "VirMidI 2-1"
std::regex virtualDeviceRegex{"^(VirMIDI) (\\d+)-(\\d+)$"};
{
// Extract the card and device numbers from the match
std::smatch match;
std::regex_search(port.name, match, virtualDeviceRegex);
if (match.size() == 4)
{
try
{
std::string devName = match[1];
int card = std::stoi(match[2]);
int device = std::stoi(match[3]);
rawMidiDevice = SS("hw:CARD=" << devName << ",DEV=" << device);
}
catch (const std::exception &ignored)
{
}
}
}
}
else
{
rawMidiDevice = SS("hw:CARD=" << port.clientName << ",DEV=" << 0);
if (port.port > 0)
{
rawMidiDevice += SS("," << port.port);
}
}
port.rawMidiDevice = std::move(rawMidiDevice);
}
port.id = SS("seq:" << port.clientName << "/" << port.name);
ports.push_back(port);
ports.push_back(std::move(port));
}
}
@@ -122,7 +156,7 @@ namespace pipedal
// Open sequencer in input mode
int rc;
rc = snd_seq_open(&seqHandle, "default", SND_SEQ_OPEN_DUPLEX, 0);
rc = snd_seq_open(&seqHandle, "default", SND_SEQ_OPEN_DUPLEX, 0);
if (rc < 0)
{
// convert rc to message
@@ -131,14 +165,15 @@ namespace pipedal
snd_seq_set_client_name(seqHandle, "PiPedal");
inPort = snd_seq_create_simple_port(seqHandle, "PiPedal:in",
SND_SEQ_PORT_CAP_WRITE | SND_SEQ_PORT_CAP_SUBS_WRITE,
SND_SEQ_PORT_TYPE_MIDI_GENERIC |
SND_SEQ_PORT_TYPE_MIDI_GM | SND_SEQ_PORT_TYPE_APPLICATION);
SND_SEQ_PORT_CAP_WRITE | SND_SEQ_PORT_CAP_SUBS_WRITE,
SND_SEQ_PORT_TYPE_MIDI_GENERIC |
SND_SEQ_PORT_TYPE_MIDI_GM | SND_SEQ_PORT_TYPE_APPLICATION);
if (inPort < 0)
{
// convert rc to message
throw std::runtime_error(SS("Failed to open ALSA sequencer:" << snd_strerror(inPort)));
}
snd_seq_nonblock(seqHandle, 1); // Set sequencer to non-blocking mode
}
AlsaSequencer::~AlsaSequencer()
{
@@ -190,69 +225,93 @@ namespace pipedal
throw std::runtime_error("ALSA port not found");
}
bool AlsaSequencer::ReadMessage(AlsaMidiMessage &message)
void AlsaSequencer::WaitForMessage() {
auto fdCount = snd_seq_poll_descriptors_count(seqHandle, POLLIN);
if (fdCount == 0) return;
this->pollFds.resize(fdCount);
snd_seq_poll_descriptors(seqHandle, pollFds.data(), fdCount, POLLIN);
poll(pollFds.data(), fdCount, -1); // Wait indefinitely for input
}
bool AlsaSequencer::ReadMessage(AlsaMidiMessage &message, bool block)
{
// Event loop
snd_seq_event_t *event = nullptr;
bool success = false;
if (snd_seq_event_input(seqHandle, &event) >= 0 && event)
{
success = true;
// Extract timestamp information
message.timestamp = event->time.tick;
message.realtime_sec = event->time.time.tv_sec;
message.realtime_nsec = event->time.time.tv_nsec;
// Process MIDI event here, e.g. NOTEON, NOTEOFF, etc.
switch (event->type)
while (true) {
bool success = false;
int rc = snd_seq_event_input(seqHandle, &event);
if (rc < 0) {
if (rc == -EAGAIN) {
if (!block) {
return false;
}
WaitForMessage();
} else {
// Handle other errors
throw std::runtime_error(SS("ALSA sequencer input error: " << snd_strerror(rc)));
}
} else if (event)
{
case SND_SEQ_EVENT_NOTEON:
message.cc0 = 0x90 | event->data.note.channel; // channel
message.cc1 = event->data.note.note; // note
message.cc2 = event->data.note.velocity; // velocity
break;
case SND_SEQ_EVENT_NOTEOFF:
// handle note-off
message.cc0 = 0x80 | event->data.note.channel; // channel
message.cc1 = event->data.note.note; // note
message.cc2 = event->data.note.off_velocity; // off velocity
break;
case SND_SEQ_EVENT_KEYPRESS:
message.cc0 = 0xA0 | event->data.note.channel; // polyphonic key pressure
message.cc1 = event->data.note.note; // note
message.cc2 = event->data.note.velocity; // pressure
break;
case SND_SEQ_EVENT_CONTROLLER:
message.cc0 = 0xB0 | event->data.control.channel; // control change
message.cc1 = event->data.control.param; // controller number
message.cc2 = event->data.control.value; // controller value
break;
case SND_SEQ_EVENT_PGMCHANGE:
message.cc0 = 0xC0 | event->data.control.channel; // program change
message.cc1 = event->data.control.value; // program number
message.cc2 = 0; // unused
break;
case SND_SEQ_EVENT_CHANPRESS:
message.cc0 = 0xD0 | event->data.control.channel; // channel pressure
message.cc1 = event->data.control.value; // pressure value
message.cc2 = 0; // unused
break;
case SND_SEQ_EVENT_PITCHBEND:
message.cc0 = 0xE0 | event->data.control.channel; // pitch bend
message.cc1 = (event->data.control.value >> 7) & 0x7F; // MSB
message.cc2 = event->data.control.value & 0x7F; // LSB
break;
case SND_SEQ_EVENT_CONTROL14:
case SND_SEQ_EVENT_NONREGPARAM:
case SND_SEQ_EVENT_REGPARAM:
case SND_SEQ_EVENT_SONGPOS:
default:
success = false;
break;
success = true;
// Extract timestamp information
message.timestamp = event->time.tick;
message.realtime_sec = event->time.time.tv_sec;
message.realtime_nsec = event->time.time.tv_nsec;
// Process MIDI event here, e.g. NOTEON, NOTEOFF, etc.
switch (event->type)
{
case SND_SEQ_EVENT_NOTEON:
message.cc0 = 0x90 | event->data.note.channel; // channel
message.cc1 = event->data.note.note; // note
message.cc2 = event->data.note.velocity; // velocity
break;
case SND_SEQ_EVENT_NOTEOFF:
// handle note-off
message.cc0 = 0x80 | event->data.note.channel; // channel
message.cc1 = event->data.note.note; // note
message.cc2 = event->data.note.off_velocity; // off velocity
break;
case SND_SEQ_EVENT_KEYPRESS:
message.cc0 = 0xA0 | event->data.note.channel; // polyphonic key pressure
message.cc1 = event->data.note.note; // note
message.cc2 = event->data.note.velocity; // pressure
break;
case SND_SEQ_EVENT_CONTROLLER:
message.cc0 = 0xB0 | event->data.control.channel; // control change
message.cc1 = event->data.control.param; // controller number
message.cc2 = event->data.control.value; // controller value
break;
case SND_SEQ_EVENT_PGMCHANGE:
message.cc0 = 0xC0 | event->data.control.channel; // program change
message.cc1 = event->data.control.value; // program number
message.cc2 = 0; // unused
break;
case SND_SEQ_EVENT_CHANPRESS:
message.cc0 = 0xD0 | event->data.control.channel; // channel pressure
message.cc1 = event->data.control.value; // pressure value
message.cc2 = 0; // unused
break;
case SND_SEQ_EVENT_PITCHBEND:
message.cc0 = 0xE0 | event->data.control.channel; // pitch bend
message.cc1 = (event->data.control.value >> 7) & 0x7F; // MSB
message.cc2 = event->data.control.value & 0x7F; // LSB
break;
case SND_SEQ_EVENT_CONTROL14:
case SND_SEQ_EVENT_NONREGPARAM:
case SND_SEQ_EVENT_REGPARAM:
case SND_SEQ_EVENT_SONGPOS:
default:
success = false;
break;
}
snd_seq_free_event(event);
}
if (success) {
return true;
}
snd_seq_free_event(event);
}
return success;
}
int AlsaSequencer::CreateRealtimeInputQueue()
@@ -294,8 +353,6 @@ namespace pipedal
throw std::runtime_error(SS("Failed to start queue: " << snd_strerror(rc)));
}
// Set the queue for input timestamping
snd_seq_port_info_t *port_info;
snd_seq_port_info_alloca(&port_info);
@@ -348,4 +405,17 @@ namespace pipedal
return true;
}
}
std::string RawMidiIdToSequencerId(const std::vector<AlsaSequencerPort> &seqDevices, const std::string &rawMidiId)
{
for (const auto &device : seqDevices)
{
if (device.rawMidiDevice == rawMidiId)
{
return device.id;
}
}
return {};
}
} // namespace pipedal