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ALSA Sequencer Interim checkin.

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This commit is contained in:
Robin E. R. Davies
2025-06-28 18:41:44 -04:00
parent acb668853b
commit 862d5b6315
17 changed files with 801 additions and 434 deletions
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PiPedalCommon/src/include/AlsaSequencer.hpp
+192 -43
View File
@@ -25,12 +25,23 @@
#include <vector>
#include <string>
#include <alsa/asoundlib.h>
#include <alsa/seq.h>
#include <stdexcept>
#include <memory>
namespace pipedal
{
// event messages starting with 0xFF are meta events.
// data not in midi format, is variable length, and private and the second byte is the MetaEventType.
enum class MetaEventType
{
None,
Tempo,
TimeSignature,
KeySignature,
SetPositionTick,
SetPositionTime
};
struct AlsaSequencerPort
{
std::string id;
@@ -61,22 +72,172 @@ namespace pipedal
struct AlsaMidiMessage
{
uint32_t timestamp; // in microseconds (tick time if using queue)
AlsaMidiMessage()
{
size = 0;
data = fixedBuffer;
}
AlsaMidiMessage(uint8_t cc0)
{
size = 1;
data = fixedBuffer;
fixedBuffer[0] = cc0;
}
AlsaMidiMessage(uint8_t cc0, uint8_t cc1)
{
size = 2;
data = fixedBuffer;
fixedBuffer[0] = cc0;
fixedBuffer[1] = cc1;
}
AlsaMidiMessage(uint8_t cc0, uint8_t cc1, uint8_t cc2)
{
size = 3;
data = fixedBuffer;
fixedBuffer[0] = cc0;
fixedBuffer[1] = cc1;
fixedBuffer[2] = cc2;
}
AlsaMidiMessage(uint8_t *data, size_t size)
{
this->size = size;
this->data = data;
}
AlsaMidiMessage(const AlsaMidiMessage &other)
{
this->timestamp = other.timestamp;
this->realtime_sec = other.realtime_sec;
this->realtime_nsec = other.realtime_nsec;
if (other.size > 3)
{
this->size = other.size;
this->data = other.data;
}
else
{
this->size = other.size;
this->data = fixedBuffer;
for (size_t i = 0; i < other.size; ++i)
{
fixedBuffer[i] = other.fixedBuffer[i];
}
}
}
AlsaMidiMessage &operator=(const AlsaMidiMessage &other)
{
this->timestamp = other.timestamp;
this->realtime_sec = other.realtime_sec;
this->realtime_nsec = other.realtime_nsec;
if (other.size > 3)
{
this->size = other.size;
this->data = other.data;
}
else
{
this->size = other.size;
this->data = fixedBuffer;
for (size_t i = 0; i < other.size; ++i)
{
fixedBuffer[i] = other.fixedBuffer[i];
}
}
return *this;
}
AlsaMidiMessage(AlsaMidiMessage &&other)
{
this->timestamp = other.timestamp;
this->realtime_sec = other.realtime_sec;
this->realtime_nsec = other.realtime_nsec;
if (other.size > 3)
{
this->size = other.size;
this->data = other.data;
}
else
{
this->size = other.size;
this->data = fixedBuffer;
for (size_t i = 0; i < other.size; ++i)
{
fixedBuffer[i] = other.fixedBuffer[i];
}
}
}
AlsaMidiMessage &operator=(AlsaMidiMessage &&other)
{
this->timestamp = other.timestamp;
this->realtime_sec = other.realtime_sec;
this->realtime_nsec = other.realtime_nsec;
if (other.size > 3)
{
this->size = other.size;
this->data = other.data;
}
else
{
this->size = other.size;
this->data = fixedBuffer;
for (size_t i = 0; i < other.size; ++i)
{
fixedBuffer[i] = other.fixedBuffer[i];
}
}
return *this;
}
void Set(uint8_t cc0)
{
size = 1;
data = fixedBuffer;
fixedBuffer[0] = cc0;
}
void Set(uint8_t cc0, uint8_t cc1)
{
size = 2;
data = fixedBuffer;
fixedBuffer[0] = cc0;
fixedBuffer[1] = cc1;
}
void Set(uint8_t cc0, uint8_t cc1, uint8_t cc2)
{
size = 3;
data = fixedBuffer;
fixedBuffer[0] = cc0;
fixedBuffer[1] = cc1;
fixedBuffer[2] = cc2;
}
void Set(uint8_t *data, size_t size)
{
this->size = size;
this->data = data;
}
uint8_t cc0() const { return size > 0 ? data[0] : 0; }
uint8_t cc1() const { return size > 1 ? data[1] : 0; }
uint8_t cc2() const { return size > 2 ? data[2] : 0; }
uint32_t timestamp; // in microseconds (tick time if using queue)
uint64_t realtime_sec; // real-time timestamp seconds
uint32_t realtime_nsec; // real-time timestamp nanoseconds
uint8_t cc0;
uint8_t cc1;
uint8_t cc2;
size_t size = 0;
uint8_t *data = fixedBuffer;
uint8_t fixedBuffer[12];
};
/*
* AlsaSequencer - ALSA MIDI sequencer interface with real-time timestamp support
*
*
* Example usage with real-time timestamps:
*
*
* AlsaSequencer sequencer;
* sequencer.connect(clientId, portId);
*
*
* AlsaMidiMessage message;
* while (sequencer.ReadMessage(&message)) {
* // message.realtime_sec and message.realtime_nsec contain precise real-time timestamps
@@ -84,48 +245,36 @@ namespace pipedal
* printf("MIDI event at %lu.%09u seconds\n", message.realtime_sec, message.realtime_nsec);
* }
*/
class AlsaSequencer
{
protected:
AlsaSequencer() {}
public:
virtual ~AlsaSequencer() = default;
using self = AlsaSequencer;
using ptr = std::shared_ptr<self>;
static ptr Create();
static std::vector<AlsaSequencerPort> EnumeratePorts();
AlsaSequencer();
~AlsaSequencer();
public:
virtual void ConnectPort(int clientId, int portId) = 0;
virtual void ConnectPort(const std::string &id) = 0;
void ConnectPort(int clientId, int portId);
void ConnectPort(const std::string&name);
// Read a single MIDI message from the sequencer input port. A timeout of -1 blocks indefinitely.
// A timeout of 0 returns immediately.
virtual bool ReadMessage(AlsaMidiMessage &message, int timeoutMs = -1) = 0;
// Read a single MIDI message from the sequencer input port
bool ReadMessage(AlsaMidiMessage &message, bool block = true);
// currently non-functional
virtual bool GetQueueRealtime(uint64_t *sec, uint32_t *nsec) = 0;
// Get current real-time from the queue (useful for calculating precise timing)
bool GetQueueRealtime(uint64_t* sec, uint32_t* nsec);
// Get the current queue ID (returns -1 if no queue is active)
int GetQueueId() const { return queueId; }
private:
void WaitForMessage();
// Create an ALSA input queue with real-time timestamps for the given client/port
int CreateRealtimeInputQueue();
struct Connection
{
int clientId;
int portId;
};
std::vector<Connection> connections;
std::vector<struct pollfd> pollFds; // For polling input events
snd_seq_t *seqHandle = nullptr;
int inPort = -1;
int queueId = -1; // Queue for real-time timestamps
// Example: open an ALSA sequencer input port and read MIDI events continuously
void ReadMidiFromPort(int clientId, int portId);
virtual void RemoveAllConnections() = 0;
};
std::string RawMidiIdToSequencerId(const std::vector<AlsaSequencerPort> &seqDevices,const std::string &rawMidiId);
std::string RawMidiIdToSequencerId(const std::vector<AlsaSequencerPort> &seqDevices, const std::string &rawMidiId);
}