Success with gstreamer

A few weeks ago I nearly threw my laptop down the hallway at work out of frustration with Kino and Pitivi. All I wished to do was create a simple screencast using open source software. I later tried some tips I found on the Fedora Screencasting wiki only to find the recommended splice script out of date.

Though the script was broken on F8 it did give me insight into the power of the gstreamer framework. I knew that whenever I had the time I should dig in a little deeper. With the help of this Linux Conf Austrailia talk I was able to figure out what needed to be changed in order to get the splice script working again on F8.

Here's how I spliced my theora video (made with istanbul) with a wav file recorded in audacity:

gst-launch oggmux name=mux ! filesink location=ldap-gst.ogg { filesrc location=ldap.ogg ! decodebin name=v } { filesrc location=ldap-audio.wav ! decodebin name=a } { v. ! queue ! ffmpegcolorspace ! theoraenc ! queue ! mux. } { a. ! queue ! audioconvert ! vorbisenc ! queue ! mux. }

As a big fan of golfing on the command line I can appreciate convoluted oneliners. The big trick to getting the fedora-av-splice.sh script running was:

1. Remove the version number from the 'gst-launch' executable (why hard-code that anyway?)
   
2. Corrected syntax (honestly, I mostly cargo-culted this from examples I found on the interweb)
3. Changed 'rawvorbisenc' to plain old 'vorbisenc'. The talk mentioned 'gst-inspect' which for me was the key to finding out what my system could do.

Now what I would like to do is update the Fedora wiki. Sadly, I can't figure out how to edit http://fedoraproject.org/wiki/ScreenCasting. It appears to be an 'Immutable Page'. How should this get updated? Do I email the mailling list? There's probably a doc explaining this on the wiki somewhere so I'll just have to dig for it sometime (unless some knowledgeable reader can enlighten me).

Kino 1.2.0: great on F8

Today I spent some time figuring out why I couldn't get Kino's transitions working on Fedora 8. Previously I was using version 1.1.1 from the livna repository and I noticed today that a tarball for 1.2.0 existed. Building and installing it to my home dir worked like a charm. All audio and video FX are working. During FUDcon I might seen if I could update the livna package for kino so that others could benefit. I'll test it out a bit more in the meantime.

On a side note I also gave pitivi a shot. It's far from it's first 1.0 release but I must I like the interface a bit more than kino. Plus, being written in Python makes it a little more hackable.