diff options
Diffstat (limited to 'libs/backends/coreaudio/coreaudio_backend.cc')
-rw-r--r-- | libs/backends/coreaudio/coreaudio_backend.cc | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/libs/backends/coreaudio/coreaudio_backend.cc b/libs/backends/coreaudio/coreaudio_backend.cc index 09bab52469..85bd2355bc 100644 --- a/libs/backends/coreaudio/coreaudio_backend.cc +++ b/libs/backends/coreaudio/coreaudio_backend.cc @@ -17,6 +17,21 @@ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ + +/* use an additional midi message parser + * + * coreaudio does packetize midi. every packet includes a timestamp. + * With any real midi-device with a phyical layer + * 1 packet = 1 event (no concurrent events are possible on a cable) + * + * Howver, some USB-midi keyboards manage to send concurrent events + * which end up in the same packet (eg. 6 byte message: 2 note-on). + * + * An additional parser is needed to separate them + */ +#define USE_MIDI_PARSER + + #include <regex.h> #include <sys/mman.h> #include <sys/time.h> @@ -104,6 +119,13 @@ CoreAudioBackend::CoreAudioBackend (AudioEngine& e, AudioBackendInfo& info) , _dsp_load (0) , _processed_samples (0) , _port_change_flag (false) +#ifdef USE_MIDI_PARSER + , _unbuffered_bytes(0) + , _total_bytes(0) + , _expected_bytes(0) + , _status_byte(0) + , _parser_bytes(0) +#endif { _instance_name = s_instance_name; pthread_mutex_init (&_port_callback_mutex, 0); @@ -1559,6 +1581,100 @@ CoreAudioBackend::freewheel_thread () return 0; } +#ifdef USE_MIDI_PARSER +bool +CoreAudioBackend::midi_process_byte (const uint8_t byte) +{ + if (byte >= 0xf8) { + // Realtime + if (byte == 0xfd) { + // undefined + return false; + } + midi_prepare_byte_event (byte); + return true; + } + if (byte == 0xf7) { + // Sysex end + if (_status_byte == 0xf0) { + midi_record_byte (byte); + return midi_prepare_buffered_event (); + } + _total_bytes = 0; + _unbuffered_bytes = 0; + _expected_bytes = 0; + _status_byte = 0; + return false; + } + if (byte >= 0x80) { + // Non-realtime status byte + if (_total_bytes) { + _total_bytes = 0; + _unbuffered_bytes = 0; + } + _status_byte = byte; + switch (byte & 0xf0) { + case 0x80: + case 0x90: + case 0xa0: + case 0xb0: + case 0xe0: + // Note On, Note Off, Aftertouch, Control Change, Pitch Wheel + _expected_bytes = 3; + break; + case 0xc0: + case 0xd0: + // Program Change, Channel Pressure + _expected_bytes = 2; + break; + case 0xf0: + switch (byte) { + case 0xf0: + // Sysex + _expected_bytes = 0; + break; + case 0xf1: + case 0xf3: + // MTC Quarter Frame, Song Select + _expected_bytes = 2; + break; + case 0xf2: + // Song Position + _expected_bytes = 3; + break; + case 0xf4: + case 0xf5: + // Undefined + _expected_bytes = 0; + _status_byte = 0; + return false; + case 0xf6: + // Tune Request + midi_prepare_byte_event (byte); + _expected_bytes = 0; + _status_byte = 0; + return true; + } + } + midi_record_byte (byte); + return false; + } + // Data byte + if (! _status_byte) { + // Data bytes without a status will be discarded. + _total_bytes++; + _unbuffered_bytes++; + return false; + } + if (! _total_bytes) { + midi_record_byte (_status_byte); + } + midi_record_byte(byte); + return (_total_bytes == _expected_bytes) ? midi_prepare_buffered_event() : false; +} +#endif + + int CoreAudioBackend::process_callback (const uint32_t n_samples, const uint64_t host_time) { @@ -1614,7 +1730,29 @@ CoreAudioBackend::process_callback (const uint32_t n_samples, const uint64_t hos while (_midiio->recv_event (i, nominal_time, time_ns, data, size)) { pframes_t time = floor((float) time_ns * _samplerate * 1e-9); assert (time < n_samples); +#ifndef USE_MIDI_PARSER midi_event_put((void*)mbuf, time, data, size); +#else + assert (size < 128);// coremidi limit per packet + bool first_time = true; // this would need to be rememberd per port. + for (size_t mb = 0; mb < size; ++mb) { + if (first_time && !(data[mb] & 0x80)) { + /* expect a status byte at the beginning or every Packet. + * + * This parser drops messages spanning multiple packets + * (sysex > 127 bytes). + * see also libs/backends/alsa/alsa_rawmidi.cc + * which implements a complete parser per port without this limit. + */ + continue; + } + first_time = false; + + if (midi_process_byte (data[mb])) { + midi_event_put ((void*)mbuf, time, _parser_buffer, _parser_bytes); + } + } +#endif size = sizeof(data); } } |