howto screen capture video of my desktop?

[A. Jorge Garcia]

I teach Calculus at a local college and we just got SmartBoards! So, I've spent all year using Smart Notebook in WINDOZE to deliver my lessons and record them with Smart Recorder (plus voice over via wireless mic).

The problem with this scenario, asside from being forced to use WIMxP by the tech guy at my school, is that Smart Recorder outputs only WMV video files and they take forever to render. If I record 30 minutes of a class, it could take about 10 minutes to render a 20MB file after the class is over! Also, I teach Computer Science with Linux and I'd like to do all this SmartBoard stuff in Linux next year to record all my classes.

So, I'm trying to figure out 2 things:
(1) How do I use ffmpeg to do a live video screen capture of my desktop in real time with my voice and
(2) how do I get my Smart Airliner Tablet, which is a bluetooth device, to work with KNOPPIX.

Let's focus on #1 for now. I have the KNOPPIX DVD hd installed on all the PCs in my classroom/lab (25 PCs - 1 for me and 24 for my students). So, I thought I'd try on my PC:

ffmpeg -f x11grab -r 25 -s 800x600 -i 0.0 test.mpg

This way I could give my students mpegs instead of wmvs and I can record in Linux! However, I get an error that "x11grab" is not recognized. I got this syntax from the ffmpeg man page, so what gives?

Anyone who has experience with this or who can recommend a better way to do this, please help!

TIA,
AJG

[A. Jorge Garcia]

OK, I guess I could use recordmydesktop which produces oog video files and then use ffmpeg to convert them to mpgs? Does Knoppix have recordmydesktop? I understand therre's a grecordmydesktop for gnome and a krecordmydesktop or kde-recordmydesktop for kde? Is that right?

TIA,
A. Jorge Garica
http://calcpage.tripod.com/shadowfax

[Warhammer]

Mmm.. Personally I use Screen VidShot. The best tool for your objective.

[A. Jorge Garcia]

OK, so how do you use it? How about an example? Do you use it from the commandline? What's the syntax? Is it included on the knoppix cd or dvd or do I have to install it?

TIA,
A. Jorge Garcia
http://calcpage.tripod.com/shadowfax

[A. Jorge Garcia]

OK, I might as well answer my own question. I really like http://screencast-o-matic.com which is a web app that records your desktop to the mp4 format. Since its a web app, its also cross-platform so I can use it in Linux or Windows if need be. Barring that, I hear gtk-recordmydesktop is good to.

[woodsmoke]

Jorge

I've watched this thread with interest for two reasons.

a) I also teach at a college, biology and environmental science
b) I am helping to develop a Linux distro.

a) I've used record my desktop in Ubuntu and it worked ok to illustrate my own rather doofus attempt to illustrate "the succession of plant communities"(changing from moss and stuff to trees etc. over time.) But there was a lot of data loss so the discussion has given me some new ideas on apps.
b) I made a "video" of our distro last year and posted it to youtube but thought that the normal "record my desktop" lost some data and spent the money to go to a "professional" guy who had such capabilites and he did a bangup job, but there was still a lot of data loss. So, again, I'm going to try with these and see what happens.
Sooooo, the mention of these apps, and especially the web app you mentioned has opened up some new possibilities.
I know that I haven't furthered your question, but just thought I'd comment that it has helped me!
woodsmoke

[Harry Kuhman]

.... I really like... a web app that records your desktop to the mp4 format.....

Boy, this really triggers my spider-sense. A web based app should not be able to do this without installing something and if it is doing some secret install that would concern me a lot. And, of course, if something is installed you should no longer need the connection to that website.

[woodsmoke]

I dunno....

Since I needed a job when I took this one no bigge about something downloaded so..........I did the deed!

To do the deed you click the button and it gives you a 640 x 640 or something box and you can move it around to position it on the screen.

click da red buttton and away it goes, click stop and after a few seconds it goes to some kind of screen where you can save or upload or whatever.

Since the screen recording was of a compiz enabled screen and the default wallpaper, I saw a kind of vague gray, that's the Knoppix screen out in the clouds and.....;.what was curious....was that it looked as if there were "remnants of flames" on it, which I think may have been compiz thinking it was supposed to stop when I clicked stop and it may close a "video" thingy with flames, don't know. I've seen Compiz end with things going up in flames so that is more than a probable but I don't know if it is definite.

Anyway, after that one is at the guy's site and he says he'll load it with a watermark and that you can "go Pro" for five bucks.

That in and of itself is innocuous enough.

HOWEVER...............when I first went to the site I got the normal warning about an untrusted certificate and I then had to go through THREE screens to get to a rather odd text box that named the company that supposedly checked the certificate.

I didn't recognize the company...

I went through the routine again, and it stalled at the first screen... ssoooo I can't verify, or not verify, that the company is a real company that really does verification or not because I can't remember the name....it may make doughnuts and just happen to have a name that has "verify" in it.....dunno....it may be legit...or not... but going through three screens is kind of odd...

waaaayyyyyyy too long on the couch today and a few too many rumn'cokes!

The privacy statement says in no uncertain terms that they are going to collect a LOT of information when you sign up for "Pro", and it also talks about sending information to third party groups... so....

I dunno....it seemed to work once, however, going along with a CERTAIN PERSON'S SPIDEY SENSE! the whole privacy thing and then going through three screens to get to a verification company which is not OBVIOUSLY a verification company....

dunno...

maybe get your uncle to bring his video cam over and film the screen might be safer......... NAAAAHHHHH just kidding!

woodsmoke

[Clinton]

The privacy statement says in no uncertain terms that they are going to collect a LOT of information

At least you read that. It's scary how many people download and use applications without realising what they're giving away.

[woodsmoke]

That is, unfortunately, true.

I often times donate computers with a Linux on them to people in need, but one of the few that I have sold to defray expenses was to a fellow who was in the beginning of Alzheimer's and played online MahJonng and his wife wanted a computer that would not get the tons of spyware that the site downloaded onto their Windblows machine.

That wasn't his fault or hers, but she was spending a lot of money to get the thing cleaned and that with Norton on the machine...so he got to play his game and she didn't have to worry.

I used to volunteer at what was Castle Cops and the main problem was not the big viruses it was the tons of malware, and it became so routine that there was a file that we would have people download that would display the contents of their registry.

We had a spreadsheet with hundreds of rows and hundreds of columns that had the variants in the intersections of the rows and columns and if nothing really bad was in the readout then we recommended Antivir, or Spybot or such for people to automatically clean their computers.

It was waaayyyy to depressing for me and I didn't last long, but the other folks there did a heroic job and are now completely unsung.

Yeah if people would only just do a little reading and thinking they would save themselves so much pain...

woodsmoke