Fix MIDI input with ALSA.
Reworked the handling of ALSA RawMidi input to support: - Running Status. - RealTime Category messages arriving during other messages data. - Multiple connected RawMidi interfaces.
This commit is contained in:
Ibrahn Sahir
parent
0d28820c81
commit
81575174cb
2 changed files with 153 additions and 67 deletions
|
|
@ -37,85 +37,135 @@
|
|||
|
||||
#include <errno.h>
|
||||
|
||||
static int get_message_size(uint8_t message) {
|
||||
switch (message & 0xF0) {
|
||||
case 0x80: // note off
|
||||
case 0x90: // note on
|
||||
case 0xA0: // aftertouch
|
||||
case 0xB0: // continuous controller
|
||||
case 0xE0: // pitch bend
|
||||
case 0xF2: // song position pointer
|
||||
return 3;
|
||||
MIDIDriverALSAMidi::MessageCategory MIDIDriverALSAMidi::msg_category(uint8_t msg_part) {
|
||||
if (msg_part >= 0xf8) {
|
||||
return MessageCategory::RealTime;
|
||||
} else if (msg_part >= 0xf0) {
|
||||
// System Exclusive begin/end are specified as System Common Category messages,
|
||||
// but we separate them here and give them their own categories as their
|
||||
// behaviour is significantly different.
|
||||
if (msg_part == 0xf0) {
|
||||
return MessageCategory::SysExBegin;
|
||||
} else if (msg_part == 0xf7) {
|
||||
return MessageCategory::SysExEnd;
|
||||
}
|
||||
return MessageCategory::SystemCommon;
|
||||
} else if (msg_part >= 0x80) {
|
||||
return MessageCategory::Voice;
|
||||
}
|
||||
return MessageCategory::Data;
|
||||
}
|
||||
|
||||
case 0xC0: // patch change
|
||||
case 0xD0: // channel pressure
|
||||
case 0xF1: // time code quarter frame
|
||||
case 0xF3: // song select
|
||||
size_t MIDIDriverALSAMidi::msg_expected_data(uint8_t status_byte) {
|
||||
if (msg_category(status_byte) == MessageCategory::Voice) {
|
||||
// Voice messages have a channel number in the status byte, mask it out.
|
||||
status_byte &= 0xf0;
|
||||
}
|
||||
|
||||
switch (status_byte) {
|
||||
case 0x80: // Note Off
|
||||
case 0x90: // Note On
|
||||
case 0xA0: // Polyphonic Key Pressure (Aftertouch)
|
||||
case 0xB0: // Control Change (CC)
|
||||
case 0xE0: // Pitch Bend Change
|
||||
case 0xF2: // Song Position Pointer
|
||||
return 2;
|
||||
|
||||
case 0xF0: // SysEx start
|
||||
case 0xF4: // reserved
|
||||
case 0xF5: // reserved
|
||||
case 0xF6: // tune request
|
||||
case 0xF7: // SysEx end
|
||||
case 0xF8: // timing clock
|
||||
case 0xF9: // reserved
|
||||
case 0xFA: // start
|
||||
case 0xFB: // continue
|
||||
case 0xFC: // stop
|
||||
case 0xFD: // reserved
|
||||
case 0xFE: // active sensing
|
||||
case 0xFF: // reset
|
||||
case 0xC0: // Program Change
|
||||
case 0xD0: // Channel Pressure (Aftertouch)
|
||||
case 0xF1: // MIDI Time Code Quarter Frame
|
||||
case 0xF3: // Song Select
|
||||
return 1;
|
||||
}
|
||||
|
||||
return 256;
|
||||
return 0;
|
||||
}
|
||||
|
||||
void MIDIDriverALSAMidi::InputConnection::parse_byte(uint8_t byte, MIDIDriverALSAMidi &driver,
|
||||
uint64_t timestamp) {
|
||||
switch (msg_category(byte)) {
|
||||
case MessageCategory::RealTime:
|
||||
// Real-Time messages are single byte messages that can
|
||||
// occur at any point.
|
||||
// We pass them straight through.
|
||||
driver.receive_input_packet(timestamp, &byte, 1);
|
||||
break;
|
||||
|
||||
case MessageCategory::Data:
|
||||
// We don't currently forward System Exclusive messages so skip their data.
|
||||
// Collect any expected data for other message types.
|
||||
if (!skipping_sys_ex && expected_data > received_data) {
|
||||
buffer[received_data + 1] = byte;
|
||||
received_data++;
|
||||
|
||||
// Forward a complete message and reset relevant state.
|
||||
if (received_data == expected_data) {
|
||||
driver.receive_input_packet(timestamp, buffer, received_data + 1);
|
||||
received_data = 0;
|
||||
|
||||
if (msg_category(buffer[0]) != MessageCategory::Voice) {
|
||||
// Voice Category messages can be sent with "running status".
|
||||
// This means they don't resend the status byte until it changes.
|
||||
// For other categories, we reset expected data, to require a new status byte.
|
||||
expected_data = 0;
|
||||
}
|
||||
}
|
||||
}
|
||||
break;
|
||||
|
||||
case MessageCategory::SysExBegin:
|
||||
buffer[0] = byte;
|
||||
skipping_sys_ex = true;
|
||||
break;
|
||||
|
||||
case MessageCategory::SysExEnd:
|
||||
expected_data = 0;
|
||||
skipping_sys_ex = false;
|
||||
break;
|
||||
|
||||
case MessageCategory::Voice:
|
||||
case MessageCategory::SystemCommon:
|
||||
buffer[0] = byte;
|
||||
received_data = 0;
|
||||
expected_data = msg_expected_data(byte);
|
||||
skipping_sys_ex = false;
|
||||
if (expected_data == 0) {
|
||||
driver.receive_input_packet(timestamp, &byte, 1);
|
||||
}
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
int MIDIDriverALSAMidi::InputConnection::read_in(MIDIDriverALSAMidi &driver, uint64_t timestamp) {
|
||||
int ret;
|
||||
do {
|
||||
uint8_t byte = 0;
|
||||
ret = snd_rawmidi_read(rawmidi_ptr, &byte, 1);
|
||||
|
||||
if (ret < 0) {
|
||||
if (ret != -EAGAIN) {
|
||||
ERR_PRINT("snd_rawmidi_read error: " + String(snd_strerror(ret)));
|
||||
}
|
||||
} else {
|
||||
parse_byte(byte, driver, timestamp);
|
||||
}
|
||||
} while (ret > 0);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
void MIDIDriverALSAMidi::thread_func(void *p_udata) {
|
||||
MIDIDriverALSAMidi *md = static_cast<MIDIDriverALSAMidi *>(p_udata);
|
||||
uint64_t timestamp = 0;
|
||||
uint8_t buffer[256];
|
||||
int expected_size = 255;
|
||||
int bytes = 0;
|
||||
|
||||
while (!md->exit_thread.is_set()) {
|
||||
int ret;
|
||||
|
||||
md->lock();
|
||||
|
||||
for (int i = 0; i < md->connected_inputs.size(); i++) {
|
||||
snd_rawmidi_t *midi_in = md->connected_inputs[i];
|
||||
do {
|
||||
uint8_t byte = 0;
|
||||
ret = snd_rawmidi_read(midi_in, &byte, 1);
|
||||
if (ret < 0) {
|
||||
if (ret != -EAGAIN) {
|
||||
ERR_PRINT("snd_rawmidi_read error: " + String(snd_strerror(ret)));
|
||||
}
|
||||
} else {
|
||||
if (byte & 0x80) {
|
||||
// Flush previous packet if there is any
|
||||
if (bytes) {
|
||||
md->receive_input_packet(timestamp, buffer, bytes);
|
||||
bytes = 0;
|
||||
}
|
||||
expected_size = get_message_size(byte);
|
||||
// After a SysEx start, all bytes are data until a SysEx end, so
|
||||
// we're going to end the command at the SES, and let the common
|
||||
// driver ignore the following data bytes.
|
||||
}
|
||||
InputConnection *connections = md->connected_inputs.ptrw();
|
||||
size_t connection_count = md->connected_inputs.size();
|
||||
|
||||
if (bytes < 256) {
|
||||
buffer[bytes++] = byte;
|
||||
// If we know the size of the current packet receive it if it reached the expected size
|
||||
if (bytes >= expected_size) {
|
||||
md->receive_input_packet(timestamp, buffer, bytes);
|
||||
bytes = 0;
|
||||
}
|
||||
}
|
||||
}
|
||||
} while (ret > 0);
|
||||
for (size_t i = 0; i < connection_count; i++) {
|
||||
connections[i].read_in(*md, timestamp);
|
||||
}
|
||||
|
||||
md->unlock();
|
||||
|
|
@ -139,7 +189,7 @@ Error MIDIDriverALSAMidi::open() {
|
|||
snd_rawmidi_t *midi_in;
|
||||
int ret = snd_rawmidi_open(&midi_in, nullptr, name, SND_RAWMIDI_NONBLOCK);
|
||||
if (ret >= 0) {
|
||||
connected_inputs.insert(i++, midi_in);
|
||||
connected_inputs.insert(i++, InputConnection(midi_in));
|
||||
}
|
||||
}
|
||||
|
||||
|
|
@ -160,7 +210,7 @@ void MIDIDriverALSAMidi::close() {
|
|||
thread.wait_to_finish();
|
||||
|
||||
for (int i = 0; i < connected_inputs.size(); i++) {
|
||||
snd_rawmidi_t *midi_in = connected_inputs[i];
|
||||
snd_rawmidi_t *midi_in = connected_inputs[i].rawmidi_ptr;
|
||||
snd_rawmidi_close(midi_in);
|
||||
}
|
||||
connected_inputs.clear();
|
||||
|
|
@ -179,7 +229,7 @@ PackedStringArray MIDIDriverALSAMidi::get_connected_inputs() {
|
|||
|
||||
lock();
|
||||
for (int i = 0; i < connected_inputs.size(); i++) {
|
||||
snd_rawmidi_t *midi_in = connected_inputs[i];
|
||||
snd_rawmidi_t *midi_in = connected_inputs[i].rawmidi_ptr;
|
||||
snd_rawmidi_info_t *info;
|
||||
|
||||
snd_rawmidi_info_malloc(&info);
|
||||
|
|
|
|||
|
|
@ -46,12 +46,48 @@ class MIDIDriverALSAMidi : public MIDIDriver {
|
|||
Thread thread;
|
||||
Mutex mutex;
|
||||
|
||||
Vector<snd_rawmidi_t *> connected_inputs;
|
||||
class InputConnection {
|
||||
public:
|
||||
InputConnection() = default;
|
||||
InputConnection(snd_rawmidi_t *midi_in) :
|
||||
rawmidi_ptr{ midi_in } {}
|
||||
|
||||
// Read in and parse available data, forwarding any complete messages through the driver.
|
||||
int read_in(MIDIDriverALSAMidi &driver, uint64_t timestamp);
|
||||
|
||||
snd_rawmidi_t *rawmidi_ptr = nullptr;
|
||||
|
||||
private:
|
||||
static const size_t MSG_BUFFER_SIZE = 3;
|
||||
uint8_t buffer[MSG_BUFFER_SIZE] = { 0 };
|
||||
size_t expected_data = 0;
|
||||
size_t received_data = 0;
|
||||
bool skipping_sys_ex = false;
|
||||
void parse_byte(uint8_t byte, MIDIDriverALSAMidi &driver, uint64_t timestamp);
|
||||
};
|
||||
|
||||
Vector<InputConnection> connected_inputs;
|
||||
|
||||
SafeFlag exit_thread;
|
||||
|
||||
static void thread_func(void *p_udata);
|
||||
|
||||
enum class MessageCategory {
|
||||
Data,
|
||||
Voice,
|
||||
SysExBegin,
|
||||
SystemCommon, // excluding System Exclusive Begin/End
|
||||
SysExEnd,
|
||||
RealTime,
|
||||
};
|
||||
|
||||
// If the passed byte is a status byte, return the associated message category,
|
||||
// else return MessageCategory::Data.
|
||||
static MessageCategory msg_category(uint8_t msg_part);
|
||||
|
||||
// Return the number of data bytes expected for the provided status byte.
|
||||
static size_t msg_expected_data(uint8_t status_byte);
|
||||
|
||||
void lock() const;
|
||||
void unlock() const;
|
||||
|
||||
|
|
|
|||
Loading…
Reference in a new issue