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wiki:screencasttutorial [2010/11/08 13:22] – autostaticwiki:screencasttutorial [2012/04/16 03:09] – old revision restored 171.64.197.42
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 Not satisfied with the quality of the screencasts made with [[http://recordmydesktop.sourceforge.net/about.php|recordMyDesktop]] I started looking for an alternative that might yield better results, especially the video part. The JACK support of recordMyDesktop is a big plus and quite solid too but recordMyDesktop converts all video to Theora only and this has proved inconvenient when uploaded to a webservice like YouTube. The video quality just degraded too much.\\  Not satisfied with the quality of the screencasts made with [[http://recordmydesktop.sourceforge.net/about.php|recordMyDesktop]] I started looking for an alternative that might yield better results, especially the video part. The JACK support of recordMyDesktop is a big plus and quite solid too but recordMyDesktop converts all video to Theora only and this has proved inconvenient when uploaded to a webservice like YouTube. The video quality just degraded too much.\\ 
 So I needed a different toolset. For the video part I chose [[http://www.ffmpeg.org/|FFmpeg]] for its unrivaled flexibility and support for input and output formats. FFmpeg also has JACK support but I found the JACK input client to be too xrun prone so for the audio part I chose [[apps:all:jack_capture|jack_capture]], a lightweight, flexible commandline driven recording tool.\\  So I needed a different toolset. For the video part I chose [[http://www.ffmpeg.org/|FFmpeg]] for its unrivaled flexibility and support for input and output formats. FFmpeg also has JACK support but I found the JACK input client to be too xrun prone so for the audio part I chose [[apps:all:jack_capture|jack_capture]], a lightweight, flexible commandline driven recording tool.\\ 
-To prevent webservices like YouTube having to downscale or upscale your videos, which deteriorates the quality of your videos drastically, I run the whole screencast session in a nested X server with the help of [[http://www.freedesktop.org/wiki/Software/Xephyr|Xephyr]].+To prevent webservices like YouTube having to downscale or upscale your videos, which deteriorates the quality of your videos drastically, you can optionally run the whole screencast session in a nested X server with the help of [[http://www.freedesktop.org/wiki/Software/Xephyr|Xephyr]]. 
  
 ===== Requirements ===== ===== Requirements =====
  
   * A recent version of FFmpeg compiled with support for the h.264 protocol   * A recent version of FFmpeg compiled with support for the h.264 protocol
-  * jack_capture +  * [[apps:all:jack_capture|jack_capture]] 
-  * Xephyr +  * Xephyr [optional] 
-  * A video editor, I use [[http://www.openshotvideo.com/|OpenShot]] myself+  * A video editor, I use [[http://www.openshotvideo.com/|OpenShot]] or [[http://www.kdenlive.org/|kdenlive]] myself
   * A screen with a minimal horizontal resolution of 1280 pixels   * A screen with a minimal horizontal resolution of 1280 pixels
  
-===== Set up the screencast session =====+ 
 +===== Screencast script ===== 
 + 
 +I use a simple script like this: 
 + 
 +<code>#!/bin/bash 
 + 
 +DATE=`date +%Y%m%d` 
 +TIME=`date +%Hh%M` 
 + 
 +# Start screencast 
 +xterm -e jack_capture -b 24 $HOME/Screencasts/screencast_audio_$DATE-$TIME.wav & 
 +ffmpeg -an -f x11grab -r 30 -s 1280x720 -i 0:0 -vcodec libx264 -vpre lossless_ultrafast -threads 4 $HOME/Screencasts/screencast_video_$DATE-$TIME.mkv 
 + 
 +killall jack_capture</code> 
 + 
 +You might need to adjust the number of threads for the ffmpeg -threads parameter to match the number of cores of your CPU. If unsure, set it to 0, ffmpeg should then set the numbers of threads automatically.  
 + 
 +jack_capture by default captures all the audio that is connected to system:ouput. If you want to be able to manually make connections to jack_capture with jack_connect, qjackctl or whatever, you have to pass it the -mc option (you need at least version 0.9.58 for this) 
 + 
 +===== Optional Xephyr script  =====
  
 Set up a Xephyr nested X server with a resolution of 1280x720 as this resolution yields the best result when uploading the final video to a webservice like YouTube. I use a little script for this: Set up a Xephyr nested X server with a resolution of 1280x720 as this resolution yields the best result when uploading the final video to a webservice like YouTube. I use a little script for this:
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 As you can see I set up a session by calling /etc/X11/Xsession. In Ubuntu >= 9.10 this starts up a new fresh Gnome session and because I use IceWM for my main session in which I run Xephyr this works very well. If you're using Gnome as your DE using /etc/X11/Xsession won't work properly so in that case you will have to resort to a different start-up option. This also holds for distributions that don't use /etc/X11/Xsession. As you can see I set up a session by calling /etc/X11/Xsession. In Ubuntu >= 9.10 this starts up a new fresh Gnome session and because I use IceWM for my main session in which I run Xephyr this works very well. If you're using Gnome as your DE using /etc/X11/Xsession won't work properly so in that case you will have to resort to a different start-up option. This also holds for distributions that don't use /etc/X11/Xsession.
  
-Now start your screencast within the nested X server, I use a second script for this:+TODO:other distros 
  
-<code>#!/bin/bash+After you ran this Xephyr script, you should run the above screencast script, taking care of making the following changes to it: 
  
-DATE=`date +%Y%m%d` +  * add the line "export DISPLAY=:2.0" after the TIME line. 
-TIME=`date +%Hh%M` +  * change -i 0:0 ffmpeg option to -i :2.  
-export DISPLAY=:2.0+  * add the -display 0:0 option to the xterm line (so it won't appear in your screencast).
  
-# Start screencast +Within the Xephyr session I also use a [[http://gnome-look.org/content/show.php/Basic?content=126559|plain cursor theme without drop shadow]] because ffmpeg doesn't capture the drop shadow properly. As of [[http://git.ffmpeg.org/?p=ffmpeg;a=commit;h=191a50db964768ca4418bdf00b26159a77879b9c|FFmpeg revision 25690]] this has been fixed.
-xterm -display :0.0 -e jack_capture -b 24 $HOME/Screencasts/screencast_audio_$DATE-$TIME.wav & +
-ffmpeg -an -f x11grab -r 30 -s 1280x720 -i :2 -vcodec libx264 -vpre lossless_ultrafast -threads 4 $HOME/Screencasts/screencast_video_$DATE-$TIME.mkv +
- +
-killall jack_capture</code> +
- +
-You might need to adjust the number of threads for the ffmpeg -threads parameter to match the number of cores of your CPU. If unsure, set it to 0, ffmpeg should then set the numbers of threads automatically. Within the Xephyr session I also use a [[http://gnome-look.org/content/show.php/Basic?content=126559|plain cursor theme without drop shadow]] because ffmpeg doesn't capture the drop shadow properly.+
  
 ===== Editing, rendering and uploading to a webservice ===== ===== Editing, rendering and uploading to a webservice =====
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 [[http://www.youtube.com/watch?v=tusCeI1aQ4c|Tiny Tutorial: Vocoding in Qtractor]] [[http://www.youtube.com/watch?v=tusCeI1aQ4c|Tiny Tutorial: Vocoding in Qtractor]]
 +
 +[[http://www.youtube.com/watch?v=azj7OAzP_GI|The Infinite Repeat - Unaware of a Direction]]
 +
 +[[http://www.youtube.com/watch?v=peMR6Agc7Es|The Infinite Repeat - Money or Love (DJ AutoStatic Remix)]]
wiki/screencasttutorial.txt · Last modified: 2013/06/02 15:45 by 127.0.0.1