19 Mar
2012
19 Mar
'12
12:40 a.m.
I am forwarding a mail and sample code from Ed Sweeney
(with permission).
He'd appreciate any comments.
---------------------------------------------------------------------
Joel,
Programming jack is fun.
Check out the attached, it is jack's simple_session_client.c in perl.
I don't know how to test the savequit session events but support for
them is coded and the sample processing totally works. I rewrote
metro.c metronome in perl too, works.
I have generated API libs for perl, python, ruby, and lua. Each of
them has a reworked simple_client that works. Ruby has a bug with the
metronome I haven't been able to find yet.
I'm sure there are lots of bugs and wrong design choices and poorly
chosen names but it is a start!
The build system is messy. I'll put a tarball on a server and tar up
a binary installable perl module today. If this looks like it will be
usable, I'll put it on github.
-- simple_client.pl --
#!/usr/bin/perl
use jackscript;
use strict;
use warnings;
use Cwd 'abs_path';
my $jc;
if (defined($ARGV[0])) {
print("restarting with uuid $ARGV[0]\n");
$jc = jackscript::JsClient->new("simpler", $ARGV[0],
$jackscript::JackSessionID);
} else {
$jc = jackscript::JsClient->new("simpler", undef,
$jackscript::JackNullOption);
}
my $in = $jc->registerPort("input", $jackscript::JackPortIsInput);
my $out = $jc->registerPort("output", $jackscript::JackPortIsOutput);
$jc->activate();
my $done = undef;
until($done) {
my $jsevent = $jc->getEvent(-1);
if ($jsevent->getType() == $jackscript::PROCESS) {
my $inbuffer = $in->getBuffer();
my $outbuffer = $out->getBuffer();
my $nframes = $outbuffer->length();
for (my $i = 0; $i < $nframes; $i++) { #copy input to putput
my $s = $inbuffer->getf($i);
$outbuffer->setf($i,$s);
}
} elsif ($jsevent->getType() == $jackscript::SAMPLE_RATE_CHANGE) {
my $sr = $jc->getSampleRate();
print("sample rate change event: sample rate is now $sr\n");
} elsif ($jsevent->getType() == $jackscript::SHUTDOWN) {
print("jack shutdown event\n");
$done = "done!";
} elsif ($jsevent->getType() == $jackscript::SESSION) {
my $dir = $jsevent->getSessionDir();
my $uuid = $jsevent->getUuid();
my $se_type = $jsevent->getSessionEventType();
my $setypeTxt = $se_type == $jackscript::JackSessionSave ? "save" :
"quit";
print("session notification: path $dir, uuid $uuid, type:
$setypeTxt\n");
if ($se_type == $jackscript::JackSessionSaveAndQuit) {
$done = "done!";
}
my $script_path = abs_path($0);
my $cmd = "perl $script_path $uuid";
$jsevent->setCommandLine($cmd); #tell jackd how to restart us
} else {
die("unknown event type\n");
}
$jsevent->complete();
}
print("simple_client.pl ended\n");
--
Joel Roth