I think the answer belongs to the list. Maybe others will correct me...
On Sunday 26 September 2010 12:04:17 you wrote:
> Hi Arnold, your hint is a very revelation to me! I have spent the night
> thinking about it and now I have a question: if I drive the beat counter
> via the sampling-clock (you mean the internal clock of the sound card,
> right?) and the alsa process is in a blocking mode, the audio-thread
> become itself a sort of metronome where a chunk of data is a single tick,
> doesn't it?
The audio-thread becomes the metronome. But don't mix the chunks of data with
the tick of your bars:beats:ticks.
You get block of samples from the device (to write to or read from), you know
what samplingrate you use, you know how many samples you already processed.
From that you calculate your clock.
BTW: It sounds as if you are just beginning to write audio-apps: Start with
jack, its api for clients is easier then alsa's. At least that what I'm told,
I never used the alsa-api.
Another advantage of jack is that you get the global jack-transport for free.
Which means your sampler/looper will sync with your other soft-synths and with
your recording app.
Have fun,
Arnold
Hi guys,
first of all forgive my not-so-perfect English :-)
I'm writing down some code for a minimal loop player based on two threads: one handles a beat counter, the other feeds the soundcard with audio frames, through ALSA. When the beat counter has completed a full cycle (e.g. 4/4) it simply rewinds the PCM data to byte 0 making a seamless loop. Really straightforward.
Now, I'm wondering how to implement the metronome side: should I rely on something like usleep/nanosleep or ALSA layer could offer an advanced timer? Another potential issue would come from latency, obviously present within the audio thread (due to ALSA): what happens when the beat counter restarts the audio sample but an alsa frame is still being written to the soundcard?
Thank you in advance for any suggestion!
Tb
After a flurry of belated Spring cleaning, I am happy to
announce updated versions of the following DSSI plugins
and host:
Xsynth-DSSI version 0.9.4, an analog-style (VCOs-VCF-VCA)
DSSI synth:
http://dssi.sourceforge.net/download.html#Xsynth-DSSI
WhySynth version 20100922, a versatile DSSI synth:
http://www.smbolton.com/whysynth.html
ghostess version 20100923, a lightweight GTK+ DSSI host:
http://www.smbolton.com/linux.html
New in these releases:
* GUI knobs now use cairo (when available) for smooth, anti-
aliased rendering.
* Patch and configuration file handling is now more graceful
in its handling of different locales.
* WhySynth: new minBLEP oscillator waveform (Clipped Saw).
* WhySynth: new effect (Sean Costello's Csound reverb).
* Six months' to a year's worth of unreleased bug fixes and
code cleanups.
Have fun,
-Sean Bolton
A new version of Jacker is out:
http://bitbucket.org/paniq/jacker
Changes:
* Command-Line support. If a song name is passed to Jacker at startup,
it will load it.
* "install" command. You can now install Jacker globally.
* New logo. Less glossy, more elegant.
* Fixed a terrible timing error that introduced a jitter as big as the
current latency.
* Default number of tracks raised from 8 to 16.
* Tracks can be renamed. Double-click track to pick a new name.
* Mute buttons for each track. Not that reliable at the moment. Last
played sound may hang. In this case, stop, then continue playing.
* MIDI input to connect your keyboard, to test sounds before you track
them. Click on a track label to route your keyboard to the particular
output.
* Initial JACK transport support. It's useful for synchronizing a
recording to a DAW like Ardour. Can be switched on with the "Sync"
button in the toolbar. Not too stable on start-up and loop borders.
When in trouble, stop, seek, then start.
Hiho,
I managed to get SuperCollider and JACK running on my IGEP [1], on the pre-
configured Ubuntu on the SD, but of course the audio is still bumpy.
So... I'm looking for a RT kernel for this little machine... Anyone have any
pointers?
I did find this one: http://beagleboard.org/project/omap-rt-patch/
but the project doesn't show much recent activity.
and... I also noticed that JACK didn't want to run with alsa as backend; oss
as backend works though (but gives the bumpy sound).
Anyone willing to share their experiences doing linux audio on ARM processors?
sincerely,
Marije
[1] http://www.igep-platform.com/
Please pardon the cross-posting as well as the belated nature of the message.
L2Ork Virginia Tech's Linux Laptop Orchestra is back on tour Sept. 19-21st with performances at Duke University, WSSU, and UNCG as part of the New Music Festival (http://uncgnmf2010.org/).
For additional info on performances:
http://l2ork.music.vt.edu/main/?page_id=21
About L2Ork:
http://l2ork.music.vt.edu/main/http://l2ork.music.vt.edu/main/?page_id=5
L2Ork on Facebook:
http://www.facebook.com/group.php?gid=117918141555131
L2Ork PD resources including custom version of Pd extended and supporting externals (under construction):
http://l2ork.music.vt.edu/main/?page_id=56
Should you happen to have any questions, suggestions or concerns, please do not hesitate to contact me.
Best wishes,
Ivica Ico Bukvic, D.M.A.
Composition, Music Technology
Director, DISIS Interactive Sound & Intermedia Studio
Director, L2Ork Linux Laptop Orchestra
Assistant Co-Director, CCTAD
CHCI, CS, and Art (by courtesy)
Virginia Tech
Dept. of Music - 0240
Blacksburg, VA 24061
(540) 231-6139
(540) 231-5034 (fax)
ico(a)vt.edu
http://www.music.vt.edu/faculty/bukvic/
Hi,
Does anyone knows if is possible to make a RME HDSPe RayDAT work
properly under Linux?
I cannot make it sync correctly with the adat outputs, even if in the
alsamixer I select "Sample Clock Source": "Internal 48Khz", the slave
devices got sync as 44.1Khz, and it doesn't sound properly (not only the
SR).
I only found by google some mails by Fernando, Florian and a few others,
but any of those helped me to make it work. I also tried changing
HDSPM_freqReg to 100 MHz (see [1]) but didn't seem to help (anyway, on
monday I'll do further tests with that).
Any news on that?
Can someone give me some hints to make further tests?
Thanks in advance,
Natanael.
[1] http://www.mentby.com/dougall-irving/rme-hdspe-raydat.html
Is there a mass-market (a cheap module from china/taiwan/hongkong)
equivalent of the OptoRec and OptoGen , which could be usefully hooked
up to a few of these:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=230418195291
to make a useful multichannel D/A for an ADAT lightpipe ; the optorec
could likewise be paired with external A/D's or used to "vampire" an
I2S signal from external digital gear w/o digital outputs.
Also, experience with assembling and/or using the OpenRec/OptoGen?
http://electronics.dantimax.dk/Kits/Digital_audio/11329401182.html
..................
OptoRec and OptoGen
ADAT digital audio receiver and transmitter circuit
These kits is [sic] an 8-channel interface circuit using the ADAT
protocol. They supports the sample rates 44.1 and 48kHz and up to 24
bits.
The boards can be used for adding an ADAT input to a DAC, an ADAT
output to an ADC or for DIY projects. The receiver board includes an
ADAT input, ADAT output, a wordclock input and I2S outputs. The
transmitter board includes an ADAT output and I2S inputs.
The kits use SMD parts, so some SMD experience may be needed to
assemble the board. SOT-23-5 parts are used, so a fine-tipped
soldering iron (or SMD tools) is needed.
..................
It's that "SMD experience" needed part that really gets me. I will
invariably get a blob of solder bridging two SMD pins, and then in the
course of trying to correct my mistake manage to get it bridging a few
more pins and melting the ic or lifting the pad of the pc board.
there's a reason i went into software. The undo key.
Niels
http://nielsmayer.com
Announcing the DSSI Soft Synth Interface version 1.1.0 release:
http://dssi.sourceforge.net/
DSSI is an audio plugin API for software instruments and effects,
based on LADSPA, the ALSA sequencer event types, and OSC (Open
Sound Control) communications.
DSSI is now supported by six full-featured hosts, several
specialized hosts, and at least twenty-four DSSI plugins. (See the
above URL for a list.)
New in the DSSI 1.1.0 release:
* New jack-dssi-host command line option '-c' to set the ALSA and JACK
client names.
* New 'dssi_list_plugins' and 'dssi_analyse_plugin' command line tools.
* Example GUIs have been updated to Qt 4.
Bugfixes:
* Fixed jack-dssi-host ALSA client ports to be of type 'application'.
* Fixed the MIDI CC mapping in trivial_synth.
* Fixed an uninitialized variable bug in less_trivial_synth.
Enjoy!
Sean Bolton
