JOGL 2 support for Ardor3D, JMonkeyEngine 3, jzy3d and NiftyGUI

The source code of JoglNewtAwtCanvas is here:
http://sourceforge.net/p/ardor3d-jogl2/code/16/tree/trunk/ardor3d-jogl2/src/main/java/com/ardor3d/framework/jogl/JoglNewtAwtCanvas.java

You can give it a try by installing Ardor3D with my renderer (follow the instructions on my personal blog) and replacing JoglAwtCanvas by JoglNewtAwtCanvas in JoglAwtExample (ardor3d-example).

Ken Russell worked on a port of Ardor3D using NEWT:
http://www.java-gaming.org/posts/ardor3d-0-4-released/message-161861/view.html#msg161861
but I have never seen his source code :(

I will try to make it work without requiring modifications in JOGL 2, I assume it is possible. The problem is that the frame handler might be called on any thread, not always AWT EDT.

On Wednesday, September 21, 2011 02:56:00 PM gouessej [via jogamp] wrote:
>
> The source code of JoglNewtAwtCanvas is here:
> http://sourceforge.net/p/ardor3d-jogl2/code/7/tree/trunk/ardor3d-jogl2/src/main/java/com/ardor3d/framework/jogl/JoglNewtAwtCanvas.java
> http://sourceforge.net/p/ardor3d-jogl2/code/7/tree/trunk/ardor3d-jogl2/src/main/java/com/ardor3d/framework/jogl/JoglNewtAwtCanvas.java 
>
> You can give it a try by installing Ardor3D with my renderer (follow the
> instructions on my personal blog) and replacing JoglAwtCanvas by
> JoglNewtAwtCanvas in JoglAwtExample (ardor3d-example).

Thx .. will have a look at it later.

>
> Ken Russell worked on a port of Ardor3D using NEWT:
> http://www.java-gaming.org/posts/ardor3d-0-4-released/message-161861/view.html#msg161861
> http://www.java-gaming.org/posts/ardor3d-0-4-released/message-161861/view.html#msg161861 
> but I have never seen his source code :(

Yup, I joined that effort, but somehow it was never picked up and merged.
IE I added some ES2 isolation etc.

>
> I will try to make it work without requiring modifications in JOGL 2, I
> assume it is possible. The problem is that the frame handler might be called
> on any thread, not always AWT EDT.

Well, sure - ok.

I would prefere a non AWT port anyways .. well, you know it :)

Cheers, Sven

It seems quite interesting. Does Kenneth still have the source code of this port?

An AWT port is better than nothing (and I already did it, it was quite straightforward except the problem of finding the appropriate method to get the context) but it will not help me to work around AWT full screen bug on Linux :(

Hi

I now use MainThread.invoke(false) to queue runnables executing OpenGL operations, it works better now but which methods of NewtCanvasAWT must be called with MainThread.invoke(false) and which one must be called on the AWT EDT? I still get sometimes some GLExceptions. Should the Newt child be created on the AWT EDT? If so, could you change the visibility of the method setNEWTChild to public please? Best regards.

On Monday, September 26, 2011 10:40:01 PM gouessej [via jogamp] wrote:
>
> Hi
>
> I now use MainThread.invoke(false) to queue runnables executing OpenGL
> operations,

Good you mention this here. Please do not!

Why not GLAutoDrawable's 'invoke(boolean wait, GLRunnable glRunnable)' ?
It's intended for this purpose (I guess).

Another best candidate would be your window's EDT.

However, NEWT's MainThread class is only a tool to
allow some OS (MacOSX) to be able to funcion somehow.
(Yup, working on it again, see commits)

MainThread's purpose is not to provide one big EDT
for rendering commands (like AWT) :)

I actually changed MainThread already, removed it's EDTUtil implementation,
so it 'justs' kicks of the Java class main thread/call and may
delegate to NSApp.run() if on MacOSX.


> it works better now but which methods of NewtCanvasAWT must be
> called with MainThread.invoke(false)
NONE

> and which one must be called on the AWT
> EDT?
All modifications to the AWT component.
This is what the AWT spec says.
After make visible, do all AWT-mods on AWT-EDT,
also the AWT setVisible(true) as well.

> I still get sometimes some GLExceptions. Should the Newt child be
> created on the AWT EDT?
The NewtCanvasAWT is an AWT component.
None of the pure NEWT window operations must be handled in a special way,
since they are all implemented to be run on their NEWT Display EDT
if required.

> If so, could you change the visibility of the method
> setNEWTChild to public please? Best regards.

Hope this helps. If in doubt, pls study the unit tests.
However, I guess the above rules of thumb should be enough.

Laters, Sven

Thank you so much. Using GLWindow.invoke(true, GLRunnable) in JoglNewtAwtCanvas solved my problems :)

but I get this at the beginning:
java.util.zip.ZipException: error in opening zip file
        at java.util.zip.ZipFile.open(Native Method)
        at java.util.zip.ZipFile.<init>(ZipFile.java:131)
        at java.util.jar.JarFile.<init>(JarFile.java:150)
        at java.util.jar.JarFile.<init>(JarFile.java:87)
        at sun.net.www.protocol.jar.URLJarFile.<init>(URLJarFile.java:90)
        at sun.net.www.protocol.jar.URLJarFile.getJarFile(URLJarFile.java:66)
        at sun.net.www.protocol.jar.JarFileFactory.get(JarFileFactory.java:71)
        at sun.net.www.protocol.jar.JarURLConnection.connect(JarURLConnection.java:122)
        at sun.net.www.protocol.jar.JarURLConnection.getJarFile(JarURLConnection.java:89)
        at com.jogamp.common.util.JarUtil.getJarFile(JarUtil.java:153)
        at com.jogamp.common.os.Platform$3.run(Platform.java:307)
        at java.security.AccessController.doPrivileged(Native Method)
        at com.jogamp.common.os.Platform.loadGlueGenRTImpl(Platform.java:298)
        at com.jogamp.common.os.Platform.<clinit>(Platform.java:207)
        at javax.media.opengl.GLProfile.<clinit>(GLProfile.java:1157)
        at com.ardor3d.framework.jogl.JoglNewtAwtCanvas.<clinit>(JoglNewtAwtCanvas.java:17)
        at com.ardor3d.example.canvas.JoglNewtAwtExample.addCanvas(JoglNewtAwtExample.java:154)
        at com.ardor3d.example.canvas.JoglNewtAwtExample.main(JoglNewtAwtExample.java:105)
java.util.zip.ZipException: error in opening zip file
        at java.util.zip.ZipFile.open(Native Method)
        at java.util.zip.ZipFile.<init>(ZipFile.java:131)
        at java.util.jar.JarFile.<init>(JarFile.java:150)
        at java.util.jar.JarFile.<init>(JarFile.java:87)
        at sun.net.www.protocol.jar.URLJarFile.<init>(URLJarFile.java:90)
        at sun.net.www.protocol.jar.URLJarFile.getJarFile(URLJarFile.java:66)
        at sun.net.www.protocol.jar.JarFileFactory.get(JarFileFactory.java:71)
        at sun.net.www.protocol.jar.JarURLConnection.connect(JarURLConnection.java:122)
        at sun.net.www.protocol.jar.JarURLConnection.getJarFile(JarURLConnection.java:89)
        at com.jogamp.common.util.JarUtil.getJarFile(JarUtil.java:153)
        at com.jogamp.common.jvm.JNILibLoaderBase.addNativeJarLibs(JNILibLoaderBase.java:162)
        at com.jogamp.common.jvm.JNILibLoaderBase.addNativeJarLibs(JNILibLoaderBase.java:188)
        at javax.media.opengl.GLProfile$1.run(GLProfile.java:122)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.media.opengl.GLProfile.initSingleton(GLProfile.java:115)
        at com.ardor3d.framework.jogl.JoglNewtAwtCanvas.<clinit>(JoglNewtAwtCanvas.java:17)
        at com.ardor3d.example.canvas.JoglNewtAwtExample.addCanvas(JoglNewtAwtExample.java:154)
        at com.ardor3d.example.canvas.JoglNewtAwtExample.main(JoglNewtAwtExample.java:105)
java.util.zip.ZipException: error in opening zip file
        at java.util.zip.ZipFile.open(Native Method)
        at java.util.zip.ZipFile.<init>(ZipFile.java:131)
        at java.util.jar.JarFile.<init>(JarFile.java:150)
        at java.util.jar.JarFile.<init>(JarFile.java:87)
        at sun.net.www.protocol.jar.URLJarFile.<init>(URLJarFile.java:90)
        at sun.net.www.protocol.jar.URLJarFile.getJarFile(URLJarFile.java:66)
        at sun.net.www.protocol.jar.JarFileFactory.get(JarFileFactory.java:71)
        at sun.net.www.protocol.jar.JarURLConnection.connect(JarURLConnection.java:122)
        at sun.net.www.protocol.jar.JarURLConnection.getJarFile(JarURLConnection.java:89)
        at com.jogamp.common.util.JarUtil.getJarFile(JarUtil.java:153)
        at com.jogamp.common.jvm.JNILibLoaderBase.addNativeJarLibs(JNILibLoaderBase.java:162)
        at com.jogamp.common.jvm.JNILibLoaderBase.addNativeJarLibs(JNILibLoaderBase.java:188)
        at jogamp.nativewindow.NWJNILibLoader$1.run(NWJNILibLoader.java:45)
        at java.security.AccessController.doPrivileged(Native Method)
        at jogamp.nativewindow.NWJNILibLoader.loadNativeWindow(NWJNILibLoader.java:41)
        at jogamp.nativewindow.x11.X11Util.initSingleton(X11Util.java:85)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:616)
        at com.jogamp.common.util.ReflectionUtil.callMethod(ReflectionUtil.java:275)
        at com.jogamp.common.util.ReflectionUtil.callStaticMethod(ReflectionUtil.java:297)
        at javax.media.nativewindow.NativeWindowFactory.initNativeImpl(NativeWindowFactory.java:147)
        at javax.media.nativewindow.NativeWindowFactory.initSingleton(NativeWindowFactory.java:195)
        at javax.media.opengl.GLProfile.initProfilesForDefaultDevices(GLProfile.java:1180)
        at javax.media.opengl.GLProfile.access$000(GLProfile.java:76)
        at javax.media.opengl.GLProfile$1.run(GLProfile.java:124)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.media.opengl.GLProfile.initSingleton(GLProfile.java:115)
        at com.ardor3d.framework.jogl.JoglNewtAwtCanvas.<clinit>(JoglNewtAwtCanvas.java:17)
        at com.ardor3d.example.canvas.JoglNewtAwtExample.addCanvas(JoglNewtAwtExample.java:154)
        at com.ardor3d.example.canvas.JoglNewtAwtExample.main(JoglNewtAwtExample.java:105)
Info: XInitThreads() called for concurrent Thread support
java.util.zip.ZipException: error in opening zip file
        at java.util.zip.ZipFile.open(Native Method)
        at java.util.zip.ZipFile.<init>(ZipFile.java:131)
        at java.util.jar.JarFile.<init>(JarFile.java:150)
        at java.util.jar.JarFile.<init>(JarFile.java:87)
        at sun.net.www.protocol.jar.URLJarFile.<init>(URLJarFile.java:90)
        at sun.net.www.protocol.jar.URLJarFile.getJarFile(URLJarFile.java:66)
        at sun.net.www.protocol.jar.JarFileFactory.get(JarFileFactory.java:71)
        at sun.net.www.protocol.jar.JarURLConnection.connect(JarURLConnection.java:122)
        at sun.net.www.protocol.jar.JarURLConnection.getJarFile(JarURLConnection.java:89)
        at com.jogamp.common.util.JarUtil.getJarFile(JarUtil.java:153)
        at com.jogamp.common.jvm.JNILibLoaderBase.addNativeJarLibs(JNILibLoaderBase.java:162)
        at com.jogamp.common.jvm.JNILibLoaderBase.addNativeJarLibs(JNILibLoaderBase.java:188)
        at jogamp.nativewindow.NWJNILibLoader$1.run(NWJNILibLoader.java:45)
        at java.security.AccessController.doPrivileged(Native Method)
        at jogamp.nativewindow.NWJNILibLoader.loadNativeWindow(NWJNILibLoader.java:41)
        at jogamp.nativewindow.jawt.JAWTUtil.<clinit>(JAWTUtil.java:80)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:616)
        at com.jogamp.common.util.ReflectionUtil.callMethod(ReflectionUtil.java:275)
        at javax.media.nativewindow.NativeWindowFactory.initSingleton(NativeWindowFactory.java:218)
        at javax.media.opengl.GLProfile.initProfilesForDefaultDevices(GLProfile.java:1180)
        at javax.media.opengl.GLProfile.access$000(GLProfile.java:76)
        at javax.media.opengl.GLProfile$1.run(GLProfile.java:124)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.media.opengl.GLProfile.initSingleton(GLProfile.java:115)
        at com.ardor3d.framework.jogl.JoglNewtAwtCanvas.<clinit>(JoglNewtAwtCanvas.java:17)
        at com.ardor3d.example.canvas.JoglNewtAwtExample.addCanvas(JoglNewtAwtExample.java:154)
        at com.ardor3d.example.canvas.JoglNewtAwtExample.main(JoglNewtAwtExample.java:105)
java.util.zip.ZipException: error in opening zip file
        at java.util.zip.ZipFile.open(Native Method)
        at java.util.zip.ZipFile.<init>(ZipFile.java:131)
        at java.util.jar.JarFile.<init>(JarFile.java:150)
        at java.util.jar.JarFile.<init>(JarFile.java:87)
        at sun.net.www.protocol.jar.URLJarFile.<init>(URLJarFile.java:90)
        at sun.net.www.protocol.jar.URLJarFile.getJarFile(URLJarFile.java:66)
        at sun.net.www.protocol.jar.JarFileFactory.get(JarFileFactory.java:71)
        at sun.net.www.protocol.jar.JarURLConnection.connect(JarURLConnection.java:122)
        at sun.net.www.protocol.jar.JarURLConnection.getJarFile(JarURLConnection.java:89)
        at com.jogamp.common.util.JarUtil.getJarFile(JarUtil.java:153)
        at com.jogamp.common.jvm.JNILibLoaderBase.addNativeJarLibs(JNILibLoaderBase.java:162)
        at com.jogamp.common.jvm.JNILibLoaderBase.addNativeJarLibs(JNILibLoaderBase.java:188)
        at jogamp.newt.NEWTJNILibLoader$1.run(NEWTJNILibLoader.java:55)
        at java.security.AccessController.doPrivileged(Native Method)
        at jogamp.newt.NEWTJNILibLoader.loadNEWT(NEWTJNILibLoader.java:51)
        at jogamp.newt.driver.x11.X11Display.<clinit>(X11Display.java:44)
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java:186)
        at jogamp.newt.DisplayImpl.getDisplayClass(DisplayImpl.java:66)
        at jogamp.newt.DisplayImpl.create(DisplayImpl.java:79)
        at com.jogamp.newt.NewtFactory.createDisplay(NewtFactory.java:101)
        at com.jogamp.newt.NewtFactory.createWindowImpl(NewtFactory.java:190)
        at com.jogamp.newt.NewtFactory.createWindow(NewtFactory.java:117)
        at com.jogamp.newt.opengl.GLWindow.create(GLWindow.java:131)
        at com.ardor3d.framework.jogl.JoglNewtAwtCanvas.<init>(JoglNewtAwtCanvas.java:28)
        at com.ardor3d.example.canvas.JoglNewtAwtExample.addCanvas(JoglNewtAwtExample.java:154)
        at com.ardor3d.example.canvas.JoglNewtAwtExample.main(JoglNewtAwtExample.java:105)

On Tuesday, September 27, 2011 10:33:07 PM gouessej [via jogamp] wrote:
>
> Thank you so much. Using GLWindow.invoke(true, GLRunnable) in
> JoglNewtAwtCanvas solved my problems :)

great it helped.

>
> but I get this at the beginning:

++

> at com.jogamp.common.util.JarUtil.getJarFile(JarUtil.java:153)
> at com.jogamp.common.os.Platform$3.run(Platform.java:307)
> at java.security.AccessController.doPrivileged(Native Method)
> at com.jogamp.common.os.Platform.loadGlueGenRTImpl(Platform.java:298)

thats our new native Jar loading/caching methodology to get the native libraries,
you might have missed my posts about it :)

this means the native jars are not where they should be,
ie next to jogl.all.jar there should be eg: jogl-all-natives-linux-amd64.jar, etc ..

if you do your own thing here,
set the sys property 'jogamp.gluegen.UseTempJarCache' to false

~Sven
--
health & wealth
mailto:[hidden email] ; http://jausoft.com
land : +49 (471) 4707742 ; cell: +49 (151) 28145941
Timezone CET: PST+9, EST+6, UTC+1

Hi

The JOGL NEWT canvas for Ardor3D should be ready to use, I have just implemented all missing wrappers.

Sven, thank you so much, confinePointer() and setPointerVisible() have been very useful.

The next step is the demo. I plan to use GLC to make a short video but my machine is not very powerful.

On Tuesday, October 18, 2011 11:21:34 PM gouessej [via jogamp] wrote:
>
> Hi
>
> The JOGL NEWT canvas for Ardor3D should be ready to use, I have just
> implemented all missing wrappers.

Perfect - KUDOS !

Now I would love to have email conversation w/ you and Ardor3D about
how they take it back (merge).
Also I like to add it to chuck (our jenkins) so we can deliver builds.

What do you think ?

>
> Sven, thank you so much, confinePointer() and setPointerVisible() have been
> very useful.

Glad it works. You are very welcome.

>
> The next step is the demo. I plan to use GLC to make a short video but my
> machine is not very powerful.

Great. I can help you out with that I guess.
I use ffmpeg for screengrab/screencasts.

~Sven

Hi

The Ardor3D team seems very busy with the switch to Google Code (and maybe GIT). However, I agree with your suggestions. The merge is crucial, it will become mandatory when JOGL 2.0 has its first stable release. We have to speak to them, we have to agree about the evolutions of this renderer (ES isolation, multiple screens support, JInput support, etc...).

Yesterday, I forgot to speak about a minor problem. One of the bugs I reported may annoy Ardor3D users who do not wish to switch to NEWT, setAutoSwapBufferMode(false) is still buggy.

I didn't know that ffmpeg could be used to perform screencasts, thanks for the tip.

Why can't a NEWT KeyEvent be set to consumed?

Is there an equivalent of setAutoSwapBufferMode(false) in NEWT? I have to call swapBuffers() manually.

On Wednesday, October 19, 2011 10:41:41 AM gouessej [via jogamp] wrote:
>
> Hi
>
> The Ardor3D team seems very busy with the switch to Google Code (and maybe
> GIT). However, I agree with your suggestions. The merge is crucial, it will
> become mandatory when JOGL 2.0 has its first stable release.

We already got 3 of them (rc 1-3), a 4th one is coming up.
So .. IMHO .. the time is now anyways.

To make things easier, I like to add your Ardor3D branch to Jenkins
as a transitional phase. Do you like to participate in this effort ?

> We have to
> speak to them, we have to agree about the evolutions of this renderer (ES
> isolation, multiple screens support, JInput support, etc...).

ES isolation sounds great.

>
> Yesterday, I forgot to speak about a minor problem. One of the bugs I
> reported may annoy Ardor3D users who do not wish to switch to NEWT,
> setAutoSwapBufferMode(false) is still buggy.

Please advise! Do we have a bugzilla bug # ?

>
> I didn't know that ffmpeg could be used to perform screencasts, thanks for
> the tip.

"ffmpeg -pass 1 -f x11grab -r 60 -threads 2 -s 854x480 -sameq -aspect 16:9 -i :0.0 output.avi"

>
> Why can't a NEWT KeyEvent be set to consumed?

I had this discussion with Rami almost a year ago,
where he asked for the same feature.

Instead of allowing an event listener to silent an event
(IMHO somehow weired), we solved it in a cooperate
and pretty generic and flexible way:

http://jogamp.org/deployment/jogamp-next/javadoc/jogl/javadoc/com/jogamp/newt/event/NEWTEvent.html#setAttachment%28java.lang.Object%29
http://jogamp.org/deployment/jogamp-next/javadoc/jogl/javadoc/com/jogamp/newt/Window.html#addKeyListener%28int,%20com.jogamp.newt.event.KeyListener%29

So you are able to be the 1st KeyListener in the queue
and able to attach an Object to the event.
The other listener may respect that object and acts accordingly,
in your case do nothing.

This mechanism is also able to do much more, ie pass results etc.

Hope this mechanism is applicable to your use case as well.

~Sven

>
> -----
> Julien Gouesse

I would like to participate to this effort but I don't know Jenkins. What can I do to help you?

setAutoSwapBufferMode(false) exists in NEWT. The bug concerning this method and GLCanvas is described here:
https://jogamp.org/bugzilla/show_bug.cgi?id=455

The mechanism can be applied to my case but I have to investigate a bit more as AWT and NEWT are different. I had to call e.consume() to avoid other layers in the GUI to treat this event.

I tried to play with Goldeneye 007 by using JArio. I recently discovered that Paul Lamb has worked on its own N64 emulator for Android. I need to implement some missing op codes, I hope he will be able to give me some information. It would be nice to have a demo of Goldeneye 007 using JOGL 2.0 :)

The discussion about Ardor3D goes on here:
http://forum.jogamp.org/JOGL-Ardor3D-td3434168.html

Hi

I will have to rewrite my port of JMonkeyEngine 3.0 as Normen asked me if it is ready.

@Sven We should host it in our official repositories as we planned, shouldn't we?

On 10/22/2012 11:08 AM, gouessej [via jogamp] wrote:
> Hi
>
> I will have to rewrite my port of JMonkeyEngine 3.0 as Normen asked me if it
> is ready
> <http://jmonkeyengine.org/groups/development-discussion-jme3/forum/topic/jogl-support-jogl2-that-is/?topic_page=3&num=15#post-194979>.
>
>
> @Sven We should host it in our official repositories as we planned, shouldn't we?

Reading .. sounds great. Kudos to your efforts!

Of course you can have a git repo to maintain,
just send me your 4k ssh public key and it will be done.

Since we always love redundancy when it comes to storage space
(not code :) - pls push to at least one other storage to be on the safe side.

Today/tomorrow I will finish some quirks w/ FFP point renderer and jake2 demo
then really pushing out RC11 .. sorry for the delay.

~Sven

Ok, I will publish the source code on Github as soon as possible for the redundancy.

Hi

The renderer based on the fixed pipeline works. The renderer based on the programmable pipeline doesn't work yet because of a bug in the handling of uniform variables.

I'm extremely happy to announce that JMonkeyEngine 3.0 is now working with JOGL 2.0. Both the renderer based on the fixed pipeline and the renderer based on the programmable pipeline are fully operational:
http://code.google.com/p/jmonkeyengine/source/detail?r=9910

Now, I have to improve the following aspects:
- applets
- switch to NEWT (but keeps some interoperability with AWT)
- off-screen canvas
- JInput

@Sven it would be nice if you simply copy my source code somewhere else so that it doesn't get lost if the core developers decide to stick to our competitor.

On 10/27/2012 03:58 PM, gouessej [via jogamp] wrote:
> I'm extremely happy to announce that JMonkeyEngine 3.0 is now working with
> JOGL 2.0. Both the renderer based on the fixed pipeline and the renderer based
> on the programmable pipeline are fully operational:
> http://code.google.com/p/jmonkeyengine/source/detail?r=9910

BIG KUDOS .. wow.

>
> Now, I have to improve the following aspects:
> - applets
> - switch to NEWT (but keeps some interoperability with AWT)
> - off-screen canvas
> - JInput

Sweet .. and yes, I know JInput is partially on my plate :)

>
> @Sven it would be nice if you simply copy my source code somewhere else so
> that it doesn't get lost if the core developers decide to stick to our
> competitor.

ofc .. and if you can give me your 4k ssh public key, you can push yourself.

~Sven

"I didn't know that ffmpeg could be used to perform screencasts, thanks for the tip."

Me neither.

Would some one be kind enough to point me to a code snippet using this ffmpeg screen cast?

I'm gessing ffmpeg screen cast converts the images into a video format which will reduce the stream size considerably, I'm I right on this?