diff options
| -rw-r--r-- | drumgizmo/input/alsamidi.cc | 100 | ||||
| -rw-r--r-- | drumgizmo/input/alsamidi.h | 2 |
2 files changed, 84 insertions, 18 deletions
diff --git a/drumgizmo/input/alsamidi.cc b/drumgizmo/input/alsamidi.cc index 3547563..48df399 100644 --- a/drumgizmo/input/alsamidi.cc +++ b/drumgizmo/input/alsamidi.cc @@ -2,7 +2,7 @@ /*************************************************************************** * alsamidi.cc * - * Copyright 2021 corrados + * Copyright 2021 Volker Fischer (github.com/corrados) ****************************************************************************/ /* @@ -28,6 +28,26 @@ #include "cpp11fix.h" // required for c++11 #include "alsamidi.h" +struct AlsaMidiInitError +{ + int const code; + const std::string msg; + + AlsaMidiInitError(int op_code, const std::string& msg) + : code{op_code} + , msg{msg} + { + } + + static inline void test(int code, const std::string& msg) + { + if(code < 0) + { + throw AlsaMidiInitError(code, msg); + } + } +}; + AlsaMidiInputEngine::AlsaMidiInputEngine() : AudioInputEngineMidi{} , in_port(0) @@ -39,31 +59,52 @@ AlsaMidiInputEngine::AlsaMidiInputEngine() AlsaMidiInputEngine::~AlsaMidiInputEngine() { + if(seq_handle != nullptr) + { + snd_seq_close(seq_handle); + } } bool AlsaMidiInputEngine::init(const Instruments& instruments) { if(!loadMidiMap(midimap_file, instruments)) { - std::cerr << "[MidifileInputEngine] Failed to parse midimap '" + std::cerr << "[AlsaMidiInputEngine] Failed to parse midimap '" << midimap_file << "'\n"; return false; } - snd_seq_open(&seq_handle, "default", SND_SEQ_OPEN_INPUT, 0); - - snd_seq_set_client_name(seq_handle, "Midi Listener"); - - in_port = - snd_seq_create_simple_port(seq_handle, "listen:in", - SND_SEQ_PORT_CAP_WRITE | - SND_SEQ_PORT_CAP_SUBS_WRITE, - SND_SEQ_PORT_TYPE_APPLICATION); + // try to initialize alsa MIDI + try + { + // it is not allowed to block in the run() function, therefore we + // have to use a non-blocking mode + int value = snd_seq_open(&seq_handle, "default", + SND_SEQ_OPEN_INPUT, SND_SEQ_NONBLOCK); + AlsaMidiInitError::test(value, "snd_seq_open"); + + value = snd_seq_set_client_name(seq_handle, "drumgizmo"); + AlsaMidiInitError::test(value, "snd_seq_set_client_name"); + + in_port = + snd_seq_create_simple_port(seq_handle, "listen:in", + SND_SEQ_PORT_CAP_WRITE | + SND_SEQ_PORT_CAP_SUBS_WRITE, + SND_SEQ_PORT_TYPE_APPLICATION); + AlsaMidiInitError::test(in_port, "snd_seq_create_simple_port"); + } + catch(AlsaMidiInitError const& error) + { + std::cerr << "[AlsaMidiInputEngine] " << error.msg + << " failed: " << snd_strerror(error.code) << std::endl; + return false; + } return true; } -void AlsaMidiInputEngine::setParm(const std::string& parm, const std::string& value) +void AlsaMidiInputEngine::setParm(const std::string& parm, + const std::string& value) { if(parm == "midimap") { @@ -94,11 +135,36 @@ void AlsaMidiInputEngine::run(size_t pos, size_t len, std::vector<event_t>& events) { assert(events.empty()); - - snd_seq_event_t* ev = nullptr; - snd_seq_event_input(seq_handle, &ev); - - processNote(ev->data.raw8.d, 12, ev->data.time.tick, events); + snd_seq_event_t* ev = NULL; + if ( snd_seq_event_input(seq_handle, &ev) >= 0 ) + { + // TODO Better solution needed: It seems that the very first raw byte + // of the MIDI message is missing the type information which is coded + // in the 4 high bits of the first byte. As a quick hack we add this + // information based on the type information of the sequence event. + std::uint8_t myd[3]; + for ( int i = 0; i < 3; ++i) + { + myd[i] = ev->data.raw8.d[i]; + } + if(ev->type == SND_SEQ_EVENT_NOTEON) + { + myd[0] += 0x90; // NoteOn + } + else if(ev->type == SND_SEQ_EVENT_NOTEOFF) + { + myd[0] += 0x80; // NoteOff + } + else if(ev->type == SND_SEQ_EVENT_KEYPRESS ) + { + myd[0] += 0xA0; // NoteAftertouch + } + + // since we do not want to introduce any additional delay for the + // MIDI processing, we set the offset to zero + processNote(myd, 3, 0, events); + } + snd_seq_free_event(ev); } void AlsaMidiInputEngine::post() diff --git a/drumgizmo/input/alsamidi.h b/drumgizmo/input/alsamidi.h index 64d207b..73e0fc8 100644 --- a/drumgizmo/input/alsamidi.h +++ b/drumgizmo/input/alsamidi.h @@ -2,7 +2,7 @@ /*************************************************************************** * alsamidi.h * - * Copyright 2021 corrados + * Copyright 2021 Volker Fischer (github.com/corrados) ****************************************************************************/ /* |