Asp Forum - Ruby screen capture movies via ImageMagick

Bil Kleb

10/8/2004 7:12:00 AM

Inspired by the videos available on http://www.rubyo... but
disappointed when trying to render the .mov format on my linux box,
I was looking at the instructions at

http://www.linuxdevcenter.com/pub/a/linux/2004/03/04/screen_capture_m...

for doing a screen capture with ImageMagick and converting the stills
to mpeg.

Their 6 line bash script to create the initial series of stills became
3 lines of Ruby.

However, I'd like to automate the whole process of capturing, converting
to mpeg, and so forth. I started thinking that I should be using the Ruby's
ImageMagick binding, RMagick, etc.

Then I thought: I should just ask here because someone has probably
figured all this out already...

Regards,
--
Bil Kleb, Hampton, Virginia

6 Answers

vruz

10/8/2004 12:40:00 PM

> Then I thought: I should just ask here because someone has probably
> figured all this out already...

Not exactly what you're asking for, but maybe it serves your purposes.

VNC2SWF uses the VNC protocol to capture the screen image and records
it to a Macromedia Flash-compatible SWF file.

The project website:
http://www.unixuser.org/~eusk...

I have used VNC2SWF, with minor tweaking of configuration parameters
seems to do a good job.

It only runs on unices/Linux but since it works over the VNC protocol,
you can capture a remote Windows screen without any problem.
This is a screen capture I made in Linux, taking it from a Windows machine:
http://vworkers.com/vru...

hope this helps,
vruz

Tim Hunter

10/8/2004 1:25:00 PM

Bil Kleb wrote:

> However, I'd like to automate the whole process of capturing, converting
> to mpeg, and so forth. I started thinking that I should be using the
> Ruby's ImageMagick binding, RMagick, etc.
>
> Then I thought: I should just ask here because someone has probably
> figured all this out already...

Very nice hack! I put a Ruby script that does this with RMagick on
codepaste.org: http://www.codepaste.org/view/paste/232?show_...
I used RMagick 1.6.0 with ImageMagick 6.1.0. I don't have the MPEG encoder
installed but I tried both MIFF and GIF formats. The resulting GIF file is
much smaller but takes a long time to write.

I could only get about 1 frame/sec (measuring with "1 Mississippi, 2
Mississippi...") and you're limited to the number of frames you can fit in
memory. That could be alleviated by capturing a relatively small window.

gabriele renzi

10/8/2004 2:11:00 PM

Bil Kleb ha scritto:
> Inspired by the videos available on http://www.rubyo... but
> disappointed when trying to render the .mov format on my linux box,
> I was looking at the instructions at
>
> http://www.linuxdevcenter.com/pub/a/linux/2004/03/04/screen_capture_m...
>
>
> for doing a screen capture with ImageMagick and converting the stills
> to mpeg.

dunno if it helps, but mauricio fernandez has a script to build the
animated gif on the rpa-base wiki that IIRC is done with RMagick, maybe
you can ask him.

Mauricio Fernández

10/8/2004 3:19:00 PM

On Fri, Oct 08, 2004 at 11:14:47PM +0900, gabriele renzi wrote:
> Bil Kleb ha scritto:
> >Inspired by the videos available on http://www.rubyo... but
> >disappointed when trying to render the .mov format on my linux box,
> >I was looking at the instructions at
> >
> > http://www.linuxdevcenter.com/pub/a/linux/2004/03/04/screen_capture_m...
> >
> >
> >for doing a screen capture with ImageMagick and converting the stills
> >to mpeg.
>
>
> dunno if it helps, but mauricio fernandez has a script to build the
> animated gif on the rpa-base wiki that IIRC is done with RMagick, maybe
> you can ask him.

It's basically http://namazu.org/~sato... with minor
modifications.

Sample animation (with colors ;)
http://rpa-base.rubyforge.org/wiki/wiki.cgi?Rpa_Base_In_Action/P...

--
Running Debian GNU/Linux Sid (unstable)
batsman dot geo at yahoo dot com

Øyvind Kolås

10/8/2004 3:52:00 PM

On Fri, 8 Oct 2004 21:39:57 +0900, vruz <horacio.lopez@gmail.com> wrote:
> > Then I thought: I should just ask here because someone has probably
> > figured all this out already...
> http://www.unixuser.org/~eusk...

Another project to mention is xvidcap / gvidcap, which can compress to
for instance mpeg4 on the fly directly from X11.

http://xvidcap.source...

--
http://pippin... - fight software patents

Carl Youngblood

10/8/2004 7:47:00 PM

All of these technologies are really cool, but they are lacking
simultaneous audio capture. That would be really cool. I guess a
decent alternative would be to take the movie and dub a narrative
track in afterwards. Any suggestions for freeware video editing tools
that can do this?

On Sat, 9 Oct 2004 00:52:10 +0900, Øyvind Kolås <islewind@gmail.com> wrote:
> On Fri, 8 Oct 2004 21:39:57 +0900, vruz <horacio.lopez@gmail.com> wrote:
> > > Then I thought: I should just ask here because someone has probably
> > > figured all this out already...
> > http://www.unixuser.org/~eusk...
>
> Another project to mention is xvidcap / gvidcap, which can compress to
> for instance mpeg4 on the fly directly from X11.
>
> http://xvidcap.source...
>
> --
> http://pippin... - fight software patents
>
>

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Ruby screen capture movies via ImageMagick