[LAU] screencasting with ffmpeg

Rustom Mody rustompmody at gmail.com
Fri Nov 5 12:07:48 UTC 2010


On Fri, Nov 5, 2010 at 3:08 PM, Jeremy Jongepier <jeremy at autostatic.com> wrote:

> Try adding an ampersand after xfce-session.

Makes no diff: Another session manager is already running is the error

>
> That is probably because of the -keybd options I used. I had to use this
> specific line to get my keyboard and mouse working properly.

Yes the keybd options cause problems sometimes and sometimes not

> man Xephyr is very informative on these options.

Well!!

Out here man Xephyr gives me hardly one screenful: the only options
mentioned are screen parent and host-cursor.
It however says its like xnest.  So install Xnest and look at its man
page. No keybd options there either. But it says see Xserver.  So I
see Xserver. Nothing there either

Anyway for now I am dropping the keybd and session call and that runs.
Script is:

#!/bin/bash
#set -x
# Set up nested X server
Xephyr -ac -screen 1024x768x16 -host-cursor -br -reset -terminate 2>
/dev/null :2 &
sleep 3
export DISPLAY=:2.0
#xfce4-session&

I am now at the point of calling the second script.  The jack_capture
is giving its own share of problems so try to only get video with the
ffmpeg call


#!/bin/bash

DATE=`date +%Y%m%d`
TIME=`date +%Hh%M`
export DISPLAY=:2.0

# Start screencast
#xterm -display :0.0 -e jack_capture -b 24
$HOME/screencast/screencast_audio_$DATE-$TIME.wav &
ffmpeg -an -f x11grab -r 30 -s 1280x720 -i :2 -vcodec libx264 -vpre
lossless_ultrafast -threads 4
$HOME/screencast/screencast_video_$DATE-$TIME.mkv

#killall jack_capture

Error I get is


[x11grab @ 0x9e04c30] device: :1 -> display: :1 x: 0 y: 0 width: 1280
height: 720
[x11grab @ 0x9e04c30] shared memory extension  found
X Error of failed request:  BadMatch (invalid parameter attributes)
  Major opcode of failed request:  130 (MIT-SHM)
  Minor opcode of failed request:  4 (X_ShmGetImage)
  Serial number of failed request:  11
  Current serial number in output stream:  11
[1]+  Segmentation fault      Xephyr -ac -screen 1024x768x16
-host-cursor -br -reset -terminate :2 2> /dev/null


> I'm not a window manager (WM)/desktop environment (DE) expert, all I
> know is that you can run into issues when using two DE's like Gnome and
> Xfce in this kind of set-up.

As far as I know I am not using gnome (now). At initial gdm login I
choose xfce rather than gnome session
>
> Best,
>
> Jeremy
>
> _______________________________________________
> Linux-audio-user mailing list
> Linux-audio-user at lists.linuxaudio.org
> http://lists.linuxaudio.org/listinfo/linux-audio-user
>


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