[ubuntu-uk] Screencast a presentation with Impress and webcam

[Bruno Girin]

On 22/01/13 17:17, James Morrissey wrote:
> Hi,
>
> I am trying to put together a presentation for a conference. The
> conference is in Australia and rather than flying there i am trying to
> make a video of my presentation, following which i will skype into the
> Q&A plenary.
>
> I had thought of simply reading the paper, but worry this might get a
> little boring for the audience. So now i am thinking of including some
> impress slides into the presentation. With that in mind i also don't
> want to simply have my voice running over an impress slide.
>
> So i have thought of trying to make a screencast with an image from my
> webcam running in one of the corners. This seems easy enough, just set
> cheese (or some equivalent) running and record my desktop. The problem
> though is that i'd ideally like to be able to run impress in full
> screen mode. Doing so, however, covers up cheese - even if i set it to
> 'always on top'.
>
> In a perfect world i'd also be able to resize the video of myself,
> during the video, so that when the slide is more relevant to what i am
> saying it dominates the picture and when what i am saying is most
> relevant, my face does.
>
> The solution i thought of was to run cheese on one workspace and
> recordmydesktop on another, where Impress is running in full screen
> mode. I'd then give the talk, clicking through impress, with both
> recordings running. Following that i'd open one instance of Totem and
> another of VLC, one showing the cheese video of me and the other the
> screencast of Impress. I'd then record that desktop, resizing the
> cheese video, of myself, at the different parts of the talk.
>
> Unfortunately it seems that running recordmydestop means that cheese
> can't record from my webcam - it can show the image, but crashed when
> i hit record and now can't find my webcam. The same thing has happened
> with Kamoso which also now can't find the webcam.
>
> I was thus thinking that i could try and use a cam corder, and take a
> video of me giving the talk before taking a screen cast of the impress
> presentation, using the audio from the talk as my cue for clicking
> through the slides. I'd then stick the two of them together, as
> described above, recording the two videos playing on top of one another.

Rather than do that, what about recording yourself with Cheese first and
save the video to a file? No need for a camcorder. Then re-run the audio
and click through the slides. Then save the screencast of the slides to
another video file.

Finally combine both videos using gstreamer picture-in-picture
compositing abilities, as explained here:
http://www.oz9aec.net/index.php/gstreamer/347-more-gstreamer-tips-picture-in-picture-compositing

You could probably use a video editor to do this as well.

Cheers,

Bruno