I've just wrote a HOWTO for the AV Linux forums on how I created my A3
MIDI vid which is basically a refinement of Jeremy's JACK screencast
tutorial with a couple of extra tips bolted on:
http://www.remastersys.com/forums/index.php?topic=1362.0
JACK Audio Screencasting
(aka The making of 'Introduction to Ardour 3.0 MIDI')
This tutorial is largely based upon an earlier one by AutoStatic here:
http://apps.linuxaudio.org/wiki/screencasttutorial
Unfortunately, that didn't quite work for me so here I present what I
had to do to get a nice JACK-friendly screencast captured.
You will need a couple of packages not included by default in AV Linux
4.2, namely the ssh server and the Xephyr nested X server
apt-get install openssh-server xserver-xephyr fluxbox
Fluxbox is entirely optional, its just what I'm using in this example.
Before running Xephyr, our 'nested X server' which will be our desktop
to capture, you need to start the ssh server, so do so as root:
/etc/init.d/ssh start
Then I run the following commands to to start Xephyr then launch
fluxbox within it - just replace 'iatn' with your username:
Xephyr -ac -host-cursor -screen 1280x720x24 -dpi 96 -br
-reset-terminate 2> /dev/null :1 &
DISPLAY=:1.0
ssh -XfC -c blowfish iatn@localhost fluxbox
Note that after typing 'DISPLAY=:1.0' you need to issue a
'DISPLAY=:0.0' to launch programs on your regular desktop again. Now
you can run a script like:
-------------
#!/bin/bash
DATE=`date +%Y%m%d`
TIME=`date +%Hh%M%S`
export DISPLAY=:1.0
# Start screencast
xterm -display :0.0 -e jack_capture --port system:capture_1 --port
system:playback_1 ~/a3midvid/a3midvid_audio_$DATE-$TIME.wav &
ffmpeg -an -f x11grab -r 30 -s 1280x720 -i :1 -vcodec libx264 -vpre
lossless_ultrafast -threads 2
~/a3midvid/a3midvid_video_$DATE-$TIME.mkv
--------------
That should capture the video on your Xephyr desktop as well as
creating a stereo wav with one channel consisting of a JACK output
channel and the other one capturing the mic connected to your first
mic input.
To fix the keyboard problem (like arrow keys not working) under
Xephyr, start Xephyr/fluxbox/xterm, input something via the keyboard
to Xephyr and then in a terminal on the host X server (not in Xephyr)
do:
DISPLAY=:0.0
xkbcomp $DISPLAY :1
This copies the XKB settings from the encompassing X server to the
Xserver under Xephyr.
When I imported my video and audio streams into KDEnlive I found I had
to displace the audio stream about 9 frames behind the video but this
value could well vary depending on numerous factors so some
experimentation may be required to get the audio and video to sync
properly.
Thanks for putting together this great video. Really useful for me as I've
just started experimenting with Ardour 3.0 in order to keep my MIDI use as
barebones as possible and not have to open Rosegarden (as great a tool as it
is). The use of A2J and velocity control where particularly useful bits of
info for me. I do have a question or two which aren't strictly Ardour 3.0
related but are pertinent to your tutorial:
1) I watched in envy as you ran A2J and plugins, alongside Ardour, and that
xrun counter stayed green. When I try and do the same, I get one-off xruns
upon A2J command and then again when trying to load plugins. Any idea why? I
don't think it's related to buffer size as I don't get continuous xruns (or
any at all) after loading the session - only on loading of apps. I'm a
perfectionist and even though those one-off xruns probably won't affect my
ability to record sound, their presence annoys me.
2) Your QJackCtl Session seemed to save and then load A2J seamlessly. When I
save a session which includes A2J, that session doesn't include A2J again
when loaded. Any ideas?
- Dan
>
> ------------------------------
>
> Message: 2
> Date: Sat, 26 Mar 2011 16:04:51 +0100 (CET)
> From: Julien Claassen <julien(a)c-lab.de>
> Subject: [LAU] persisting jack_connect problem (connection process
> doesn't finish)
> To: linux-audio-user <linux-audio-user(a)lists.linuxaudio.org>
> Cc: Linux-Audio-Dev <linux-audio-dev(a)lists.linuxaudio.org>
> Message-ID: <alpine.DEB.2.00.1103261601520.901(a)britney.spears.net>
> Content-Type: TEXT/PLAIN; format=flowed; charset=US-ASCII
>
> Hello Everyone1
> Sorry for cross posting. I just repulled Jackmp from svn, but the problem
> continues.
> Looking at the jack_connect source I can't see anything wrong, so it seems,
> that the server doesn't properly notify jack_connect/jack_disconnect of the
> finishing of the connection/disconnection process.
> Does anyone else have that problem or does anyone have a possible solution?
> many thanks and warm regards
> Julien
>
What is the problem in the first place? What applications? what context?
Thanks.
Stéphane
Hi,
it's been years and years and years
and I still don't know what settings
to put in my guitar effect box (will
be guitarix from now on I think, that
kicks and the little laptop here is
fast enough) to get a sound close to that:
http://sed.free.fr/example.mp3
The only word that comes to me when I
hear this kind of sound is 'toy,' and
it's not an insult. I love that little
toy sound. But I really don't know how
to reach it. I guess it's a lot about
EQ settings. Maybe the distortion has
to be special or I don't know... Maybe
you need a special amplifier of a given
brand and model...
Any idea anyone? anyone using guitarix
(gx_head) and able to reproduce the sound
and tell me what settings they use?
Thanks,
Cédric.
Hello
I am a total noob when it comes to sound in linux. I have Ubuntu and I
was trying to record what I was hearing. I did it but I have a question.
I installed PulseAudio Volume Control (pavucontrol) and noticed the
"Configuration" tab, where it has an "Internal Audio" profile with
options like:
* Analog Stereo Duplex
* Analog Stereo Output
* Digital Stereo Duplex (iec 958) + Analog Stereo Intput
* Digital Stero Duplex (iec 958)
* Off
I tried to find more information about these options, but there is no
"help" for this GUI. SO I was wondering if anyone could give any hints
(links, documentation etc) on what these settings are.
Vag
Hello Linux audio land!
Here is my biggest contribution to the Ardour and Linux audio
community yet to celebrate the recent public release of the Ardour 3
alpha stage.
Now that I've watched their (archive.org's) transcoding of my
'Introduction to Ardour 3.0 MIDI' video and had some initial positive
feedback off the Ardour and AV Linux forums I feel its time I shared
this with the list. Maybe I should've done this on LAA instead but I
feel this is our primary list so..
My eternal gratefulness to all the hard working devs and community
members (nearly all present on this list I'd should imagine) who made
this video possible!
Thanks for watching!
Dan(boid) MacDonald
http://www.archive.org/details/Introduction_to_Ardour_3.0_MIDI
Hello Everyone1
Sorry for cross posting. I just repulled Jackmp from svn, but the problem
continues.
Looking at the jack_connect source I can't see anything wrong, so it seems,
that the server doesn't properly notify jack_connect/jack_disconnect of the
finishing of the connection/disconnection process.
Does anyone else have that problem or does anyone have a possible solution?
many thanks and warm regards
Julien
--------
Music was my first love and it will be my last (John Miles)
======== FIND MY WEB-PROJECT AT: ========
http://ltsb.sourceforge.net
the Linux TextBased Studio guide
======= AND MY PERSONAL PAGES AT: =======
http://www.juliencoder.de
Hi,
After I posted a link to Loomer plug-ins at linuxsound.ru someone came
up and asked a very reasonable question: is there a guide how to do
compile VST natively? Could we probably make it easier for developers
to consider Linux as target platform?
P.S. I know that some people here don't like VST for either technical
or (rather) religious reasons, but I'm in favour of getting things
done, not getting things discussed. So could we please skip the "DO
NOT WANT" part? :)
Alexandre Prokoudine
http://libregraphicsworld.org
Hello everyone!
I just installed jackmp from versioning system and now my jack_connect acts
up, I have to ctrl-c it. It connects, but then jack_connect doesn't return.
Any ideas? I didn't yet try jack_disconnect.
Warmly yours
Julien
--------
Music was my first love and it will be my last (John Miles)
======== FIND MY WEB-PROJECT AT: ========
http://ltsb.sourceforge.net
the Linux TextBased Studio guide
======= AND MY PERSONAL PAGES AT: =======
http://www.juliencoder.de
