21 Dec
2012
21 Dec
'12
4:51 p.m.
I'm using Qt and C++ under Linux with ALSA. Ideally, what I'd like is a simple
example like alsa's midiseq.c or a MIDI metronome hooked up to jack so that it
outputs to fluidsynth. Then I could see the whole system in action. Is there
such an example available? I'm having some trouble understanding how all the
pieces fit together.
I have a few other questions that aren't directly related:
The first has to do with manipulating midi ctlr events to simulate various
musical techniques like legato and palm muting. What I've tried so far doesn't
sound very good. I need legato in polyphonic mode, so just overlapping notes
doesn't work. Sending a legato ctlr message doesn't seem to do anything. I'm
not looking for anything real fancy, just something to make trills & slurs
sound reasonable. I think all I want to do is to skip the attack portion of
the sample. For palm muting, I've shortened the note duration, but I'd like to
darken or thicken the timbre. Is there any simple way to do this?
Second, I've lifted a lot of glyphs from the Lilypond font and placed them in
my own font and I was wondering how and where to credit creators of these
glyphs. I've added glyphs of my own (bends, vibrato, etc.) and doctored some
others, but many are just cut, pasted, & resized from Lilypond. Before I
release any code, I'd like to get the credits properly documented.
Thanks, all.
--
7:8
21 Dec
21 Dec
6:34 p.m.
New subject: Writing a music notation editor and need some help with MIDI, Jack, and FluidSynth
On Fri, 21 Dec 2012 12:14:36 -0500
M Donalies <ingeniousnebbish(a)cox.net> wrote:
Notation Editor
Sorry I have no real help for you, but some questions out of curiousity:
Why another notation editor? What are your complaints about the existing ones?
Your mail hints at a guitar centric editor. So include tuxguitar as comparison in this
question as well.
And are there any screenshots or more text info around?
Nils
24 Dec
24 Dec
12:52 a.m.
New subject: Writing a music notation editor and need some help with MIDI, Jack, and FluidSynth
On Friday 21 December 2012 13:34:37 Nils Gey wrote:
Why another notation editor? What are your complaints
about the existing
ones? Your mail hints at a guitar centric editor. So include tuxguitar as
comparison in this question as well.
Rather than complain about other programs,
I'll just list some features I wish
to support.
1. Nested tracks/staffs to allow grouping of related instruments, like strings,
which expands to violin, viola, cello, and the like.
2. Ability to hide tracks/staffs. Consider trying to write a Concerto for Rock
Band and Orchestra.
3. Choice of staff type. Currently, it supports standard notation and
tablature, with more limited support for percussion, percussion line, and
chord line.
4. Multiple simultaneous time signatures.
5. Allow both broad brush and fine tuning properties for notes. For example,
say we have a sequence of 8th notes. They all get displayed as 8ths, but each
can have its own offset from that time used during playback. Similarly, for
duration and volume.
6. Reference clips. By clip I mean a container of events, similar to a clip in
Rosegarden or Sonar. By reference, I mean like a reference variable. The
reference clip is like a non-editable copy of an ordinary clip. Change the
ordinary one and all reference clips change as well. Useful for doubling of
instruments. Could also come in handy for the initial setup of a fugue,
especially if transposition and inversion of the original are supported.
And are there any screenshots or more text info
around?
Not yet. I plan to upload some stuff to sf within a month or so, at which
time
I'll give it a proper announcement. It's called Sqorlatti, but there's nothing
but an empty sf project page so far.
--
7:8
21 Dec
21 Dec
6:39 p.m.
New subject: Writing a music notation editor and need some help with MIDI, Jack, and FluidSynth
On Fri, Dec 21, 2012 at 12:14 PM, M Donalies <ingeniousnebbish(a)cox.net>wrote;wrote:
I'm using Qt and C++ under Linux with ALSA.
Ideally, what I'd like is a
simple
example like alsa's midiseq.c or a MIDI metronome
jack_metro (tools) combined with jack_midisine (example-clients) perhaps?
6:43 p.m.
New subject: Writing a music notation editor and need some help with MIDI, Jack, and FluidSynth
[M Donalies]
I have a few other questions that aren't directly
related:
The first has to do with manipulating midi ctlr events to simulate various
musical techniques like legato and palm muting. What I've tried so far doesn't
sound very good. I need legato in polyphonic mode, so just overlapping notes
doesn't work. Sending a legato ctlr message doesn't seem to do anything. I'm
not looking for anything real fancy, just something to make trills & slurs
sound reasonable. I think all I want to do is to skip the attack portion of
the sample. For palm muting, I've shortened the note duration, but I'd like to
darken or thicken the timbre. Is there any simple way to do this?
Even if you have a synth with a polyphonic legato implementation, you
will often find it making the wrong decisions connecting voices
because it's virtually impossible to tell voices apart when they're
lumped into one MIDI channel, especially when a voice can rest
occasionally. To make it work and sound halfway decent, I've found no
better way than to isolate and map each voice to its own channel and
make sure the synth patch on that channel interprets legato the way
you want it, if necessary with the help of additional CC messages.
Palm muting can be somewhat credibly emulated by lowering the voice
filter frequency (pretty sure fluidsynth has a CC that does that) and
quickening decay/release.
24 Dec
24 Dec
12:52 a.m.
New subject: Writing a music notation editor and need some help with MIDI, Jack, and FluidSynth
Here's my first attempt. I figured I'd start with an alsa client that outlines
the basics of what I want it to do. Once I get this, I'll try making the jack
connections from within my program. For now, I'm using QJackCtl and QSynth to
get the others going and make the connection.
The abbreviated C++ code follows. I edited out command line and i/o stuff.
After reading a data file, the vector notes holds all the relevant stuff. If
anyone's interested, I can post the entire code and the sample data file.
The first thing I don't understand is in scheduleEvents() why passing absolute
times to the queue doesn't work. And once I have absolute times, how do I do
the play/pause in the transport loop in main().
// Trivial sequencer that reads note data from a file and plays the contents.
#include <iostream>
#include <fstream>
#include <sstream>
#include <string>
#include <vector>
#include <cstdlib>
#include <alsa/asoundlib.h>
using namespace std;
enum TransportState {Stopped = 0, Paused, Playing};
// Struct holding note start time, pitch, duration, volume.
// time and duration are in ticks.
struct NoteStruct {int t; int p; int d; int v;};
vector<NoteStruct> notes;
// Usage message and exit.
void usage(string msg);
// Exit with error message.
void die(string msg);
// Create a new client.
snd_seq_t *openClient()
{
snd_seq_t *seq;
int ret = snd_seq_open(&seq, "default", SND_SEQ_OPEN_DUPLEX, 0);
if (ret < 0) die("Failed to open sequencer client.");
snd_seq_set_client_name(seq, "AJDemo Client");
return seq;
}
// Create a new output (read) port and return the port id.
int createOutputPort(snd_seq_t *seq)
{
int id = snd_seq_create_simple_port(seq, "AJDemo Port",
SND_SEQ_PORT_CAP_READ|SND_SEQ_PORT_CAP_SUBS_READ,
SND_SEQ_PORT_TYPE_MIDI_GENERIC);
if (id < 0) die("Failed to create output port.");
return id;
}
void setTempo(snd_seq_t *seq, int q, int bpm, int ppq)
{
cout << "Setting tempo, bpm = " << bpm << ", ppq =
" << ppq << endl;
int microsec = 60 * 1000000 / bpm;
snd_seq_queue_tempo_t *tempo;
snd_seq_queue_tempo_alloca(&tempo);
snd_seq_queue_tempo_set_tempo(tempo, microsec);
snd_seq_queue_tempo_set_ppq(tempo, ppq);
snd_seq_set_queue_tempo(seq, q, tempo);
}
// Put contents of notes on the queue as MIDI events.
void scheduleEvents(snd_seq_t *seq, int port, int q)
{
cout << "Scheduling events.\n";
int delta = 0;
int t = 0; // abs time
int prevT = 0;
snd_seq_event_t ev;
for (int i=0; i<notes.size(); i++)
{
t = notes[i].t;
delta = t - prevT;
snd_seq_ev_clear(&ev);
snd_seq_ev_set_source(&ev, port);
snd_seq_ev_set_subs(&ev);
snd_seq_ev_schedule_tick(&ev, q, SND_SEQ_TIME_MODE_REL, delta);
// snd_seq_ev_schedule_tick(&ev, q, 0, t);
snd_seq_ev_set_note(&ev, 1, notes[i].p, notes[i].v, notes[i].d);
snd_seq_event_output(seq, &ev);
t = prevT;
}
}
void parseCmdLine(int argc, char *argv[], int &bpm, string &fname);
// Read file fname and put resulting note data into notes.
void readFile(string fname);
// Set queue position to time t (in ticks).
void setQueuePos(snd_seq_t *seq, int port, int q, int t)
{
snd_seq_event_t ev;
snd_seq_ev_clear(&ev);
snd_seq_ev_set_source(&ev, port);
snd_seq_ev_set_subs(&ev);
snd_seq_ev_set_queue_pos_tick(&ev, q, 0);
}
int main(int argc, char *argv[])
{
string fname = "";
int bpm = 120;
int ppq = 96;
parseCmdLine(argc, argv, bpm, fname);
readFile(fname);
snd_seq_t *seq = openClient();
int clientId = snd_seq_client_id(seq);
int portId = createOutputPort(seq);
int qId = snd_seq_alloc_named_queue(seq, "AJDemo Queue");
setTempo(seq, qId, bpm, ppq);
snd_seq_start_queue(seq, qId, NULL);
snd_seq_drain_output(seq);
cout << "Press p to play/pause, s to stop, q to exit.\n";
TransportState state = Stopped;
while (true)
{
char c;
cin >> c;
if (c == 'q') break;
else if (c == 'p')
{
if (state == Playing)
{
cout << "Pausing.\n";
state = Paused;
snd_seq_stop_queue(seq, qId, NULL);
}
else if (state == Paused)
{
cout << "Resuming playing.\n";
state = Playing;
setQueuePos(seq, portId, qId, 0);
snd_seq_continue_queue(seq, qId, NULL);
}
else
{
cout << "Playing.\n";
state = Playing;
snd_seq_start_queue(seq, qId, NULL);
scheduleEvents(seq, portId, qId);
}
}
else if (c == 's')
{
cout << "Stopping.\n";
state = Stopped;
snd_seq_drop_input(seq);
snd_seq_drop_output(seq);
snd_seq_stop_queue(seq, qId, NULL);
}
snd_seq_drain_output(seq);
}
snd_seq_free_queue(seq, qId);
return 0;
}
--
7:8
4147
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4150
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linux-audio-dev@lists.linuxaudio.org
5 comments
4 participants
participants (4)
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M Donalies -
Nils Gey -
Paul Davis -
Tim Goetze