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-rw-r--r--drumgizmo/input/alsamidi.cc100
-rw-r--r--drumgizmo/input/alsamidi.h2
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)
****************************************************************************/
/*