Screen recorder - Kazam

David Klasinc bigwhale at
Sun Jan 1 10:59:18 UTC 2012

Thanks for the response Sean,

On 12/31/2011 09:03 PM, Sean McNamara wrote:

> Very cool! While I completely agree that these codec choices should be
> the default, is it easy for the user to configure Kazam to use some
> other codec? I'm not saying VP8/WebM is bad; rather, I'm saying some
> other codecs may have their uses (e.g. if you intend to distribute it
> as a raw video and you want the highest platform compatibility, VP8 is
> still not that heavily adopted on older Windows systems, or even older
> Linux distros). And the quality will be much higher if it is encoded
> directly to the format that you intend to distribute it in, rather
> than performing lossy transcoding.

VP8 is a trade-off between quality and availability. Codecs and their
support in most modern Linux distribution is still a nightmare. There
are different versions of libraries that support different sets of
parameters and options. VP8 is something that is available everywhere
and has a decent support in GStreamer.

Kazam initially encoded videos with ffmpeg and used libx264 (getting
this to work on Linux is not an easy task even now. You have to build
ffmpeg from source because of all the licensing and patent issues.

Personally I would prefer H264 over VP8. H264 is better, performance
wise and quality wise. VP8 is still a resource hog and encoding full
screen video with more than 15 fps in realtime can be challenging.

In the long run I want to support different codecs with some kind of
auto detection what is available and what not.

> The best place to get started is to read
> -- and follow the links
> from there.

I'll take a look there. Hopefully I can find a checklist document about
inclusion in the distro. :)

> Although if you are able, and there are no really challenging
> roadblocks, you should go ahead and try with GTK3.

I'd like to get rid of GTK2 as soon as possible. :) This is the very
first thing on my agenda after I deal with the codec issues and ffmpeg.

> Are there any really low-level GTK2 APIs that Kazam uses that might've
> been removed or significantly changed in GTK3? I guess I could read
> the source, but I'm getting ready to head out the door right now,
> so...

Kazam is written in python and uses pygtk. As far as I know pygtk is
becoming obsolete fast and I'll have to do a rewrite sooner or later. I
am still deciding if I should do a rewrite in Vala or keep python and
use PyGobject. I am equally unfamiliar with PyGObject and Vala. :)


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