16 Mar
2013
16 Mar
'13
11:11 p.m.
I'm trying to figure out how to make a screencast using jack.
I have a microphone connected to a firewire soundcard.
I've already excluded recordmydesktop, at least for the audio track,
because of this bug:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=649824
"recordmydesktop: Specifying --use-jack makes recordmydesktop exit with
a bad screen geometry"
recordmydesktop works fine if run without --use-jack. I may use it for
video only. What about audio?
I'm trying jack_capture, which seems nice but I can't make it work: the
.wav file generated is mute.
Can you help me?
Thanks
--
Federico
16 Mar
16 Mar
11:23 p.m.
Hi Frederico,
Am 16.03.2013 23:12, schrieb Federico Bruni:
I'm trying to figure out how to make a screencast
using jack.
I have a microphone connected to a firewire soundcard.
[...]
Can you help me?
I know that a piece of software called "KRAD RADIO" can do this kind of
stuff. Though it's still in a stage of development where things change
often and redically, version tagged as "13" in github is quite stable:
https://github.com/krad-radio/krad_radio/archive/Version_13.tar.gz
After you build from source, you basically fire up a "station", set the
(output) resolution and framerate, add the X11 capture for the live
image, add a jack input for the audio and set up the
"record-to-file"-part, specifying the codecs (WebM by default).
All commands needed are documented here:
https://wiki.mozilla.org/Krad_Radio/Commands
and some example "sessions" can be found here:
https://wiki.mozilla.org/Krad_Radio/Snippets
Live streaming the output is also possible.
If you have any questions, you can visit the devs in IRC at
irc://orc.mozilla.org/#kradradio or ask me :)
Best regards,
Jannis
17 Mar
17 Mar
12:01 a.m.
Il 16/03/2013 23:23, Jannis Achstetter ha scritto:
I know that a piece of software called "KRAD
RADIO" can do this kind of
stuff. Though it's still in a stage of development where things change
often and redically, version tagged as "13" in github is quite stable:
https://github.com/krad-radio/krad_radio/archive/Version_13.tar.gz
I had problems with compiling that tarball.
./waf configured barfed:
So I used git tags:
After you build from source, you basically fire up a
"station", set the
(output) resolution and framerate, add the X11 capture for the live
image, add a jack input for the audio and set up the
"record-to-file"-part, specifying the codecs (WebM by default).
All commands needed are documented here:
https://wiki.mozilla.org/Krad_Radio/Commands
and some example "sessions" can be found here:
https://wiki.mozilla.org/Krad_Radio/Snippets
Live streaming the output is also possible.
If you have any questions, you can visit the devs in IRC at
irc://orc.mozilla.org/#kradradio or ask me:)
Best regards,
Jannis
--
Federico
12:14 a.m.
Il 16/03/2013 23:23, Jannis Achstetter ha scritto:
I know that a piece of software called "KRAD
RADIO" can do this kind of
stuff. Though it's still in a stage of development where things change
often and redically, version tagged as "13" in github is quite stable:
https://github.com/krad-radio/krad_radio/archive/Version_13.tar.gz
I had problems with compiling that tarball.
./waf configured barfed:
fatal: Not a git repository (or any parent up to mount point /home)
...
CalledProcessError: Command '['git', 'describe',
'--tags']' returned
non-zero exit status 128
So I used the git repository and switched to version 13:
git tag -l
git checkout Version_13
Now ./waf configure starts, but...
... I'm missing a dependency, libjpeg8-turbo (it's not in Debian).
Where can I get it?
Here's the error:
from /home/fede/src/krad_radio/daemon: Test does not build: Traceback
(most recent call last):
File
"/home/fede/src/krad_radio/.waf-1.7.6-aeca75c39c28caac64540ecaf32d4f82/waflib/Tools/c_config.py",
line 460, in run_c_code
bld.compile()
File
"/home/fede/src/krad_radio/.waf-1.7.6-aeca75c39c28caac64540ecaf32d4f82/waflib/Build.py",
line 198, in compile
raise Errors.BuildError(self.producer.error)
BuildError: Build failed
-> task in 'testprog' failed (exit status 1):
{task 167348940: cxxprogram test.cpp.1.o -> testprog}
['/usr/bin/g++', 'test.cpp.1.o', '-o',
'/home/fede/src/krad_radio/.waf_build_directory/.conf_check_bef50ed8e87d0bca01165208bd7998b3/testbuild/testprog',
'-Wl,-Bstatic', '-Wl,-Bdynamic', '-lturbojpeg']
no
from /home/fede/src/krad_radio/daemon: The configuration failed
After you build from source, you basically fire up a
"station", set the
(output) resolution and framerate, add the X11 capture for the live
image, add a jack input for the audio and set up the
"record-to-file"-part, specifying the codecs (WebM by default).
All commands needed are documented here:
https://wiki.mozilla.org/Krad_Radio/Commands
and some example "sessions" can be found here:
https://wiki.mozilla.org/Krad_Radio/Snippets
Live streaming the output is also possible.
If you have any questions, you can visit the devs in IRC at
irc://orc.mozilla.org/#kradradio or ask me:)
Best regards,
Jannis
Thanks for sharing, it seems an interesting project.
You'll see me on IRC soon ;-)
Regards
--
Federico
9:26 a.m.
Am 17.03.2013 00:15, schrieb Federico Bruni:
Il 16/03/2013 23:23, Jannis Achstetter ha scritto:
You're right, that is a known limitation of version 13, I just didn't
think of it. Needs to be built from the git repo.
I know that a piece of software called "KRAD
RADIO" can do this kind of
stuff. Though it's still in a stage of development where things change
often and redically, version tagged as "13" in github is quite stable:
https://github.com/krad-radio/krad_radio/archive/Version_13.tar.gz
I had problems with compiling that tarball.
./waf configured barfed:
fatal: Not a git repository (or any parent up to mount point /home)
...
CalledProcessError: Command '['git', 'describe',
'--tags']' returned
non-zero exit status 128 Now ./waf configure starts, but...
... I'm missing a dependency, libjpeg8-turbo (it's not in Debian).
Where can I get it?
Um, ok, that never was a problem for me since every distribution I used
so far shipped libjpeg8-turbo by default. And you're right that it
doesn't seem to be available for Debian:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=602034
I don't know why KRAD hard depends on that library and there don't seem
to be ready-to-use deb-packages. You can however, try to build it from
source from http://libjpeg-turbo.virtualgl.org/
Best regards,
Jannis
9:30 a.m.
Am 17.03.2013 09:25, schrieb Jannis Achstetter:
Am 17.03.2013 00:15, schrieb Federico Bruni:
[...]
I don't know why KRAD hard depends on that library and there don't seem
to be ready-to-use deb-packages. You can however, try to build it from
source from http://libjpeg-turbo.virtualgl.org/
Oh, of course they do (just found them now):
http://sourceforge.net/projects/libjpeg-turbo/files/1.2.1/
Jannis
10:07 a.m.
Il 17/03/2013 09:30, Jannis Achstetter ha scritto:
Am 17.03.2013 09:25, schrieb Jannis Achstetter:
Thanks, I have krad installed now.
I'm going to try it
--
Federico
Am 17.03.2013 00:15, schrieb Federico Bruni:
[...]
I don't know why KRAD hard depends on that library and there don't seem
to be ready-to-use deb-packages. You can however, try to build it from
source from http://libjpeg-turbo.virtualgl.org/
Oh, of course they do (just found them now):
http://sourceforge.net/projects/libjpeg-turbo/files/1.2.1/
16 Mar
16 Mar
11:29 p.m.
Il 16/03/2013 23:12, Federico Bruni ha scritto:
I'm trying to figure out how to make a screencast
using jack.
I have a microphone connected to a firewire soundcard.
I've already excluded recordmydesktop, at least for the audio track,
because of this bug:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=649824
"recordmydesktop: Specifying --use-jack makes recordmydesktop exit with
a bad screen geometry"
recordmydesktop works fine if run without --use-jack. I may use it for
video only. What about audio?
I'm trying jack_capture, which seems nice but I can't make it work: the
.wav file generated is mute.
Can you help me?
Thanks
Actually jack_capture can record the "internal" audio, like Ardour
playback. The mic recording is not working.
I guess that it's a problem with ports...
The thing is I need to record audio both from mic and from system
(Ardour playback).
BTW, jack_capture is version 0.9.67-1
--
Federico
17 Mar
17 Mar
12:27 a.m.
On Sat, Mar 16, 2013 at 11:30 PM, Federico Bruni wrote:
Il 16/03/2013 23:12, Federico Bruni ha scritto:
Use 'jack_capture -mc', then manually establish connections.
(see 'jack_capture --advanced-options')
http://apps.linuxaudio.org/wiki/screencasttutorial
might also be helpful. The ffmpeg command will likely demand some love,
for adapting its arguments to what suits your machine.
best,
d
I'm trying to figure out how to make a
screencast using jack.
I have a microphone connected to a firewire soundcard.
I've already excluded recordmydesktop, at least for the audio track,
because of this bug:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=649824
"recordmydesktop: Specifying --use-jack makes recordmydesktop exit with
a bad screen geometry"
recordmydesktop works fine if run without --use-jack. I may use it for
video only. What about audio?
I'm trying jack_capture, which seems nice but I can't make it work: the
.wav file generated is mute.
Can you help me?
Thanks
Actually jack_capture can record the "internal" audio, like Ardour playback.
The mic recording is not working.
I guess that it's a problem with ports...
The thing is I need to record audio both from mic and from system (Ardour
playback).
11:29 a.m.
Il 17/03/2013 00:27, David Adler ha scritto:
Use 'jack_capture -mc', then manually
establish connections.
(see 'jack_capture --advanced-options')
this works, thanks!
http://apps.linuxaudio.org/wiki/screencasttutorial
might also be helpful. The ffmpeg command will likely demand some love,
for adapting its arguments to what suits your machine.
I'll give it a look tonight
--
Federico
10:12 p.m.
Il 17/03/2013 00:27, David Adler ha scritto:
Use 'jack_capture -mc', then manually
establish connections.
(see 'jack_capture --advanced-options')
How can I set it in the command line?
The input port is:
Jack: JackClient::Disconnect src = firewire_pcm:000f1b100002724f_MicIn
1+2 left_in dst = jack_capture:input1
http://apps.linuxaudio.org/wiki/screencasttutorial
might also be helpful. The ffmpeg command will likely demand some love,
for adapting its arguments to what suits your machine.
I had to replace "-vpre lossless_ultrafast" with "-preset ultrafast"
and "-i 0:0" with "-i :0.0".
http://ubuntuforums.org/showthread.php?t=1931867
It works great
--
Federico
18 Mar
18 Mar
12:10 a.m.
On Sun, Mar 17, 2013 at 10:14 PM, Federico Bruni wrote:
Thanks for posting, that does it here as well.
best,
d
Il 17/03/2013 00:27, David Adler ha scritto:
You mean setting the connection(s)? use
$ jack_connect <src> <dst>
Your <src> contains special characters (the spaces), so we
need to quote that one with single or double quiotes:
$ jack_connect 'firewire_pcm:000f1b100002724f_MicIn 1+2 left_in'
jack_capture:input1
Use 'jack_capture -mc', then manually establish connections.
(see 'jack_capture --advanced-options')
How can I set it in the command line?
The input port is:
Jack: JackClient::Disconnect src = firewire_pcm:000f1b100002724f_MicIn 1+2
left_in dst = jack_capture:input1
http://apps.linuxaudio.org/wiki/screencasttutorial
might also be helpful. The ffmpeg command will likely demand some love,
for adapting its arguments to what suits your machine.
I had to replace "-vpre lossless_ultrafast" with "-preset ultrafast"
and "-i 0:0" with "-i :0.0".
10:53 p.m.
Il 18/03/2013 00:10, David Adler ha scritto:
You mean setting the connection(s)? use
$ jack_connect <src> <dst>
Your <src> contains special characters (the spaces), so we
need to quote that one with single or double quiotes:
$ jack_connect 'firewire_pcm:000f1b100002724f_MicIn 1+2 left_in'
jack_capture:input1
It's working on the command line, but not if I copy it in the bash script.
What's wrong with it?
#!/bin/bash
DATE=`date +%Y%m%d`
TIME=`date +%Hh%M`
xterm -e jack_capture -mc -b 24
$HOME/Video/screencast/screencast_audio_$DATE-$TIME.wav &
jack_connect 'firewire_pcm:000f1b100002724f_MicIn 1+2 left_in'
jack_capture:input1 &
ffmpeg -an -f x11grab -r 30 -s 1280x800 -i :0.0 -vcodec libx264 -preset
ultrafast -threads 4 $HOME/Video/screencast/screencast_video_$DATE-$TIME.mkv
killall jack_capture
Thanks
--
Federico
19 Mar
19 Mar
1:25 a.m.
On Tue, March 19, 2013 8:54 am, Federico Bruni wrote:
Il 18/03/2013 00:10, David Adler ha scritto:
Try:
jack_connect "firewire_pcm:000f1b100002724f_MicIn 1+2 left_in"
You mean setting the connection(s)? use
$ jack_connect <src> <dst>
Your <src> contains special characters (the spaces), so we
need to quote that one with single or double quiotes:
$ jack_connect 'firewire_pcm:000f1b100002724f_MicIn 1+2 left_in'
jack_capture:input1
It's working on the command line, but not if I copy it in the bash script.
What's wrong with it?
#!/bin/bash
DATE=`date +%Y%m%d`
TIME=`date +%Hh%M`
xterm -e jack_capture -mc -b 24
$HOME/Video/screencast/screencast_audio_$DATE-$TIME.wav &
jack_connect 'firewire_pcm:000f1b100002724f_MicIn 1+2 left_in' jack_capture:input1 &
ffmpeg -an -f x11grab -r 30 -s 1280x800 -i :0.0 -vcodec libx264 -preset
ultrafast -threads 4
$HOME/Video/screencast/screencast_video_$DATE-$TIME.mkv
killall jack_capture
Thanks
--
Federico
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user(a)lists.linuxaudio.org
http://lists.linuxaudio.org/listinfo/linux-audio-user
--
Patrick Shirkey
Boost Hardware Ltd
1:36 a.m.
Il 19/03/2013 01:25, Patrick Shirkey ha scritto:
I did it before sending the email.
It doesn't work either
--
Federico
xterm -e
jack_capture -mc -b 24
>$HOME/Video/screencast/screencast_audio_$DATE-$TIME.wav &
>jack_connect 'firewire_pcm:000f1b100002724f_MicIn 1+2 left_in'
Try:
jack_connect "firewire_pcm:000f1b100002724f_MicIn 1+2 left_in"
1:42 a.m.
Il 18/03/2013 00:10, David Adler ha scritto:
I have another issue with the tutorial above.
It says:
"Now you have two separate files, an .mkv and a .wav file and because
jack_capture was started right after ffmpeg audio should be no more out
of sync then just a few millisecs."
Actually my files are out of sync because they have different durations.
Video is 5:31 and audio is 9:21.
Why?
>
http://apps.linuxaudio.org/wiki/screencasttutorial
> >>might also be helpful. The ffmpeg command will likely demand some love,
> >>for adapting its arguments to what suits your machine.
>
>I had to replace "-vpre lossless_ultrafast" with "-preset
ultrafast"
>and "-i 0:0" with "-i :0.0".
Thanks for posting, that does
it here as well. 
2:25 a.m.
On Mon, March 18, 2013 5:44 pm, Federico Bruni wrote:
Il 18/03/2013 00:10, David Adler ha scritto:
I have another issue with the tutorial above.
It says:
"Now you have two separate files, an .mkv and a .wav file and because
jack_capture was started right after ffmpeg audio should be no more out
of sync then just a few millisecs."
Actually my files are out of sync because they have different durations.
Video is 5:31 and audio is 9:21.
My first guess is a frame rate issue... like a half frame rate that is
also mistranslated from 25hz to 29.*dropframe (or vise versa). It really
doesn't matter at this point, check two things. Listen to the wave, does
it sound right"? Watch the video stream, does it look really fast? Do they
play back at the listed times?
Are you using spdif for audio in? If so, where is it getting sync from?
These are all shots in the dark. The first thing is to play them back and
see if there is an issue with audio or video or both.
--
Len Ovens
www.OvenWerks.net
>
http://apps.linuxaudio.org/wiki/screencasttutorial
> >>might also be helpful. The ffmpeg command will likely demand some
> love,
> >>for adapting its arguments to what suits your machine.
>
>I had to replace "-vpre lossless_ultrafast" with "-preset
ultrafast"
>and "-i 0:0" with "-i :0.0".
Thanks for posting, that does
it here as well.
8:08 a.m.
Il 19/03/2013 02:25, Len Ovens ha scritto:
Your guess is probably right.
The audio is ok, while the video is a bit too fast.
Yes, they play back at the listed times.
Here's what ffmpeg say:
Input #0, matroska,webm, from 'screencast_video_20130318-23h53.mkv':
Metadata:
ENCODER : Lavf54.29.104
Duration: 00:05:31.00, start: 0.000000, bitrate: 426 kb/s
Stream #0:0: Video: h264 (High 4:4:4 Predictive), yuv444p,
1280x800, SAR 1:1 DAR 8:5, 30 fps, 30 tbr, 1k tbn, 60 tbc (default)
Input #0, wav, from 'screencast_audio_20130318-23h53.wav':
Duration: 00:09:21.79, bitrate: 2304 kb/s
Stream #0:0: Audio: pcm_s24le ([1][0][0][0] / 0x0001), 48000 Hz,
stereo, s32, 2304 kb/s
But I don't understand... I've recorded at 30 fps and I'm watching at 30
fps. Why it's playing faster than the recording?
--
Federico
I have another
issue with the tutorial above.
>It says:
>"Now you have two separate files, an .mkv and a .wav file and because
>jack_capture was started right after ffmpeg audio should be no more out
>of sync then just a few millisecs."
>
>Actually my files are out of sync because they have different durations.
>Video is 5:31 and audio is 9:21.
My first guess is a frame rate issue... like
a half frame rate that is
also mistranslated from 25hz to 29.*dropframe (or vise versa). It really
doesn't matter at this point, check two things. Listen to the wave, does
it sound right"? Watch the video stream, does it look really fast? Do they
play back at the listed times?
Are you using spdif for audio in? If so, where is it getting sync from?
These are all shots in the dark. The first thing is to play them back and
see if there is an issue with audio or video or both.
10:46 a.m.
On Tue, March 19, 2013 6:10 pm, Federico Bruni wrote:
Il 19/03/2013 02:25, Len Ovens ha scritto:
Your guess is probably right.
The audio is ok, while the video is a bit too fast.
Yes, they play back at the listed times.
Here's what ffmpeg say:
Input #0, matroska,webm, from 'screencast_video_20130318-23h53.mkv':
Metadata:
ENCODER : Lavf54.29.104
Duration: 00:05:31.00, start: 0.000000, bitrate: 426 kb/s
Stream #0:0: Video: h264 (High 4:4:4 Predictive), yuv444p,
1280x800, SAR 1:1 DAR 8:5, 30 fps, 30 tbr, 1k tbn, 60 tbc (default)
Input #0, wav, from 'screencast_audio_20130318-23h53.wav':
Duration: 00:09:21.79, bitrate: 2304 kb/s
Stream #0:0: Audio: pcm_s24le ([1][0][0][0] / 0x0001), 48000 Hz,
stereo, s32, 2304 kb/s
But I don't understand... I've recorded at 30 fps and I'm watching at 30
fps. Why it's playing faster than the recording?
It possible that your machine was dropping frames while recording. You can
slow down playback 'stretch" the video to the timelength you require.
http://ffmpeg.org/trac/ffmpeg/wiki/How%20to%20speed%20up%20/%20slow%20down%…
--
Patrick Shirkey
Boost Hardware Ltd
I have
another issue with the tutorial above.
My first guess is a frame rate issue... like
a half frame rate that is
also mistranslated from 25hz to 29.*dropframe (or vise versa). It really
doesn't matter at this point, check two things. Listen to the wave, does
it sound right"? Watch the video stream, does it look really fast? Do
they
play back at the listed times?
Are you using spdif for audio in? If so, where is it getting sync from?
These are all shots in the dark. The first thing is to play them back
and
see if there is an issue with audio or video or both. It says:
"Now you have two separate files, an .mkv and a .wav file and because
jack_capture was started right after ffmpeg audio should be no more
out
of sync then just a few millisecs."
Actually my files are out of sync because they have different
durations.
>Video is 5:31 and audio is 9:21.
11:48 p.m.
Il 19/03/2013 10:46, Patrick Shirkey ha scritto:
It possible that your machine was dropping frames
while recording. You can
slow down playback 'stretch" the video to the timelength you require.
http://ffmpeg.org/trac/ffmpeg/wiki/How%20to%20speed%20up%20/%20slow%20down%…
thanks, that helped
I need to figure out how to avoid this problem when recording
I'll see in the weekend
--
Federico
2:43 p.m.
On Tue, March 19, 2013 12:10 am, Federico Bruni wrote:
Il 19/03/2013 02:25, Len Ovens ha scritto:
>> I have another issue with the tutorial above.
>> >It says:
>> >"Now you have two separate files, an .mkv and a .wav file and because
>> >jack_capture was started right after ffmpeg audio should be no more
>> out
>> >of sync then just a few millisecs."
>> >
>> >Actually my files are out of sync because they have different
>> durations.
>> >Video is 5:31 and audio is 9:21.
The audio is ok, while the video is a bit too fast.
Yes, they play back at the listed times.
Here's what ffmpeg say:
Input #0, matroska,webm, from 'screencast_video_20130318-23h53.mkv':
Metadata:
ENCODER : Lavf54.29.104
Duration: 00:05:31.00, start: 0.000000, bitrate: 426 kb/s
Stream #0:0: Video: h264 (High 4:4:4 Predictive), yuv444p,
1280x800, SAR 1:1 DAR 8:5, 30 fps, 30 tbr, 1k tbn, 60 tbc (default)
That looks pretty solid.
But I don't understand... I've recorded at 30
fps and I'm watching at 30
fps. Why it's playing faster than the recording?
I would think either the recording app is skipping frames because it
doesn't have time to grab them or because the next frame is the same as
the last (and so it expects to output the same frame a second time, but
somehow fails). My understanding of video in an analog context is much
better than in digital context :)
Does the video playback seem to be the same speed all the way through or
speed up and slow down?
--
Len Ovens
www.OvenWerks.net
11:49 p.m.
Il 19/03/2013 14:42, Len Ovens ha scritto:
I would think either the recording app is skipping
frames because it
doesn't have time to grab them or because the next frame is the same as
the last (and so it expects to output the same frame a second time, but
somehow fails). My understanding of video in an analog context is much
better than in digital context:)
Does the video playback seem to be the same speed all the way through or
speed up and slow down?
It seems constant, but I'm not 100% sure.
I'll do some specific video to understand it better..
Thanks
--
Federico
4202
days inactive
4205
days old
linux-audio-user@lists.linuxaudio.org
21 comments
5 participants
participants (5)
-
David Adler -
Federico Bruni -
Jannis Achstetter -
Len Ovens -
Patrick Shirkey