[ubuntu-in] Screencast using Istanbul

[Ravi Shanker]

On Thu, 2007-05-17 at 18:04 +0530, Onkar Shinde wrote:
> On 5/17/07, Ravi Shanker <ra21vi at gmail.com> wrote:
> > Hello Friends,
> > About the idea to upload istanbul created screencasts to youtube, I have
> > something to share. I don't think it would really be feasible idea. Why?
> > First, istanbul has many limitations,
> >         * you cannot set the video quality
> >         * the quality looks like set to 80%
> >         * text is unreadable when video is downsized
> 
> The istanbul applet has a context menu from where you should be able
> to set various options. The options that are not exposed through UI
> should be editable from gconf-editor.
> Text becoming unreadable when downsized might well be problem of
> Theora or the way it is downsized, I am not sure.
> 
> > Youtube takes and re-sizes the source video to 320x240, quality of video
> > deteriorates very much, and text completely becomes unreadable(think of
> > 1024x786 video being re-sized down to 320x240, by 3.2 ratio) .
> > There is other desktop session recorders better than istanbul, it is
> > gtk-record-mydesktop and xvidcap.
> 
> I would always prefer using Free format instead of any Restricted
> format. I agree that there might not be enough support for some Free
> format but we can always find some solution.
> 
> > Any solution? Well since to make the thing redable, we will have to
> > record and focus that section of screen where there is current activity
> > is. Also, the output video size should be 1.33333 ratio, no package
> > mentioned does allow choosing the desktop area using manual size entry,
> > its driven by mouse so we can't fix it to some custom size accurately.
> > For youtube since the acceptable format is 320x480, we will have to
> > first record the full desktop video using gtk-record-mydesktop and then
> > edit it using some video editors where we will have to crop down the
> > things to fit in 320x240 size without resizing (to prevent text
> > readability).
> 
> Istanbul allows you to record part of the screen. You may want to try that.
> 
> > So, it becomes tough task to produce quality video for screencasts. If
> > there is someone who knows video editing on Linux using
> > Lives/Cinelerra/Kino/Jahshaka, then we can do it.
> <snip>
> >
> > The other solution is not to use the Youtube, where there is size
> > limitation. ....
> >
> </snip>
> 
> There is a java applet from fluendo which can play Theora/Ogg video.
> If we decide to host videos on some other server than youtube then
> this can be useful. People who have nough bandwidth can watch these
> videos online. Others can download then from some other machine. When
> we get enough video tutorial we can make a CD which can be distributed
> by community members with Ubuntu CD.
> 
> 
> 
> Onkar
> -- 
> Passion - Some people climb mountains - others write Free software.
> Don't ask why - the reason is the same.
> 

As I said earlier, there is much limitation with istanbul. And you
cannot set much preferences with istanbul, its limited.
things you can set is video size, but just full, medium or quarter, not
something like 320x240. 
Also, all the settings given in gconf is just provided in right click
interface menu except the frame rate.

Text readability loss is not something related to bad decoding, but
also, whenever you resize, the screen text will always get unreadable,
no matter what you do. All the text you see in subtitles and in movies
are bigger enough and there is shadow for contrast preservation. So you
got the idea. To make a better screencast, we need to capture the
session in many parts and then edit it and combine with some Video
Editor (NLE).

Now what we can do is, just decide where we can have a bigger storage
for screencasts. We do record those adn if possible edit, with good
quality. And adding in the screencast will be not just open, we will
only upload those which are needed, and are in good quality.