Comments on: Screencasting in Linux!

By: Kevin Kofler

Kevin Kofler — Fri, 13 Feb 2009 14:12:12 +0000

You need my patch for Audacity http://cvs.fedoraproject.org/viewvc/rpms/audacity/devel/audacity-1.3.5-portaudio-non-mmap-alsa.patch?revision=1.1&view=markup to get it to work with PulseAudio. (The same patch also applies to the upstream PortAudio v19. It adds support for non-mmap ALSA devices such as PulseAudio’s ALSA plugin.) For Fedora 10, there’s a patched audacity in updates-testing. For Ubuntu 8.10 “Intrepid Ibex”, see: https://launchpad.net/~diwic/+archive/ppa . Mandriva also has a testing package somewhere. For other distros, I don’t know.

By: tom

tom — Thu, 12 Feb 2009 11:38:40 +0000

the package ogmtools provides a program called ogmmerge. If your working with ogg audio and theora video it will join them all together for you into a single video file.

ogmmerge -o out.ogm audio.ogg vidoe.ogv

Presto!

you can even add other audio tracks ie other languages to your screencasts by specifying more than one audio file.

…Of course thats only good if you want an ogm video file.

By: Andy Allan

Andy Allan — Thu, 12 Feb 2009 10:46:40 +0000

I recently made some screencasts here at work, using gtk-recordmydesktop and the sound recorder app in ubuntu 8.10 – like you I found the built-in sound recording of recordmydesktop to be choppy, but running the two apps simultaneously was fine. Weird.

I’d also recommend kdenlive for the editing / transcoding – I’ve spent the last week trying to put together presentations for running on MacBooks and kdenlive has been a godsend for all the transcoding work, especially with the huge variety of output transcodings that Just Work.

By: Alan Pope

Alan Pope — Thu, 12 Feb 2009 10:30:48 +0000

Just a couple of points. Don’t blame pulseaudio for the loss of sync in recordmydesktop. It’s _always_ been like that, since before pulseaudio was started.

Another video conversion tool you might want to look at is Handbrake (http://handbrake.fr). It’s GPL and has a nice graphical frontend to ffmpeg. One especially neat feature is the ability to have “profiles” to target specific devices (ipod touch for example). Another handy feature is the capability to queue up video conversions.

Worth a look.

By: opensourcecat

opensourcecat — Thu, 12 Feb 2009 10:26:50 +0000

…or you cuold just simply use Kdenlive for all that stuff…

By: Thomas R.

Thomas R. — Thu, 12 Feb 2009 09:30:56 +0000

You may want to look at kdenlive (kdenlive.sf.net) for video editing

By: quikee

quikee — Thu, 12 Feb 2009 06:40:03 +0000

You actually reencoded audio from mp3 to aac and video from OGG Theora to mpeg4 (ASP). This is why the file is smaller but you probably lost a lot of quality in this process.

It would be better (easier) if you would encode audio to OGG Vorbis in the first step instead of MP3 and then you could combine both to OGG container via GStreamer (I don’t know if MP3 would work with Vorbis) or you could combine them to Matroska.

For example:
gst-launch filesrc location=audiofile.mp3 ! mux. filesrc location=videofile.ogv ! oggdemux ! mux. matroskamux name=mux ! filesink location=result.mkv

or if you have both as Vorbis and Theora:
gst-launch filesrc location=audiofile.oga ! oggdemux ! mux. filesrc location=videofile.ogv ! oggdemux ! mux. oggmux name=mux ! filesink location=result.ogg

By: atomopawn

atomopawn — Thu, 12 Feb 2009 06:26:17 +0000

Or, if you like, I can give you some space on my web server. I have to admit I’m very interested in the result of all that media file manipulation….

By: Dread Knight

Dread Knight — Thu, 12 Feb 2009 05:28:15 +0000

Nice post! But are you really serious about the ‘no place to upload it’ part? Because the internet is full of free good file hosts….

http://www.mediafire.com
http://www.drop.ip
http://www.box.net
and so on, just take your pick, upload and paste link. It’s a no-brainer. Learn to make good use of the internet.
(also there are video hosting sites like youtube and vimeo.com heh)