Video Shader App How To

Video Shader App How To

Marwan Y. Ansari

3D Application Research Group

[email protected]

Feb 28, 2003

The purpose of this document is to briefly discuss how to run the Video Shader application developed by ATI Research, Inc. This document is written for intermediate through expert users. This document assumes you have DX9 or later from Microsoft installed on your system. If you do not have DX9 or later installed the app will fail resulting in bad karma for you and your neighbor.

Getting started

When the app starts no streams are loaded and nothing is rendered. Click on the File menu to open either

live video (Video Capture Source)

stream from a file (Open File)

an image file (Texture File)

All options are valid on the ATI Radeon 9700 All-In-Wonder, but only the Open File and Texture option is valid on Radeon 9700's that are NOT All-In-Wonders.

When the stream has started the default shader will be loaded. The default shader simply displays the contents of the stream without any effects or modifications.

The app starts in windowed mode. This allows users the opportunity to start a stream before switching to fullscreen mode. Starting new streams is only possible in windowed mode.

Live Video

If you do not see any video

Make sure that your camera is properly connected to your Radeon 9700 All-In-Wonder adapter and that its turned on.

Make sure that you have selected File/Open Capture Source.

Either hit Control+I or the "I" button in the tool bar to cycle through the video inputs. By default the app comes up on Composite. Hitting Control+I once will change you to Tuner, hitting Control+I again will put you on S-Video. Hitting Control+I a third time returns you to Composite.

Using the menu

At stream start time, a menu will be visible on the screen for about 15 seconds. You may use the up and down arrow keys to select different shader effects. After about 15 seconds the menu will disappear. Pressing almost any key will redisplay it. Hitting the escape key will clear it.

Fullscreen Mode

You may switch to fullscreen mode by clicking on the 5^th toolbar button from the left (it looks like a TV), or hitting ALT+Enter. The stream you selected will be restarted from its beginning and the default shader will be loaded after the switch to fullscreen mode has been completed.

Selecting Shaders and Shader Effects

FullScreen Mode

When running in fullscreen mode you may select one of the shaders from the menu by choosing up or down arrow. It is also possible to select a shader effect by selecting F1-F9, F11, or 1-6 on the keyboard. There is no difference between these quickload keys and the shaders in the menu.

Windowed Mode

When running in windowed mode all the choices above apply plus many more. When in windowed mode you may right click on the window left of the stream and select from the pull down menus a shader to insert. This way you can create new effects from the existing shaders very quickly.

Adding New Shader Files

Consult the document "High Level Video Shader Program Layout.doc" for information.

Hot Keys

As mentioned above the F'Keys and some number keys will load predefined shader effects files. Below is a list of other keys that will be needed to run the app:

Control+S - Toggle the cycling of shaders. This turns on/off the automatic switching of shaders. Cycling is turn on by default in Fullscreen mode, and off by default in windowed mode.

Control+A - Toggle the cycling of Transition effects. Under the key F11 is a shader effect known as Wipe Transitions developed by Chris Oat. There are approximately 11 different transition effects. To change the transition effects by hand hit the tab key. Cycling transition effects is turned off by default.

Control+C - Snap compositing image. This only effects the Image Recompositing shader. This shader allows you to snap an image of one scene, then reposition the camera, and snap a background image (Control+B). You will then see any changes from the background image appear in sepia tone onto the Composite image. For example with the image compositing shader loaded )

Point the camera out a window.

Hit Control+C . that image is now stored as the compositing image.

Point the camera somewhere else.preferably, somewhere where nothing is moving.

Hit Control+B.store that   image as a background image.

Now walk into the cameras view.

You should see yourself in Sepia tone in front of the window scene from step 2. If you do not, click the mouse toward the left side of the video image displayed. That changes the threshold of what is considered different between the current frame and the background image.

This method is not perfect but will demonstrate some of the power of the Radeon 9700 All-In-Wonder.

Control+B - Snap background image. This image is "subtracted" from the currently captured frame when the Image Recompositing or the Image Segmentation shaders are loaded. The Image Segmentation shader also uses a threshold.

Control+D - Dump a screen shot of the current shader. Screen shot will be in the same directory as "VideoShader.exe" and will have the name "VideoShaderSnapShot###.bmp".

Control+I - Cycles through the input sources. There are 3 choices, Composite (default), Tuner, and S-Video.

Escape - Toggles menu on and off.

Space bar - Toggles the preview window so you see what the live feed looks like before the shaders effect it.

Tab - Tab has 2 functions. It will cycle through the transition maps (as mentioned above) as well as cycle through the 3 Fun House mirrors. Press either F3 or F4 to see the fun house mirror shaders. Press F11 to see the transition effects.

Control+X - Exit..do you really need me to explain this? J

ALT+Enter - Toggles between fullscreen and windowed mode.

Toolbar buttons

The tool bar buttons in order from left to right:

Toggle Input selection

Play

Pause

Stop

Switch to Fullscreen

Reload ALL Shaders

Reload only currently selected shader in treeview

NOTE: Hitting Reload All Shaders will cause all shader to be unloaded. So after hitting it, you will need to select your shaders again.

Conclusion

I hope this short document is enough to get you started. If you have questions, my email address is at the top of this doc. ---Marwan Ansari