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- [Image] The Lurker's Guide to Video
-
- Welcome to the Lurker's Guide, a repository for the little-known,
- undocumented knowledge that you need in order to write any sort of video app
- on SGI machines. This Guide is not for the squeamish. Some of the material
- contained in here may be too graphic, or possibly even too useful, for the
- average educated computer science professional. We hear that some of this
- information might even survive the PSFP (Positive Spin Filtration Process)
- and make it into official documentation.
-
- This collection of documents does not represent SGI, and is not an official
- SGI publication. The entire contents of this document are the personal
- observations, and/or opinions, of the lurkers. All errors and opinions in it
- are ours alone. SGI makes no guarantees about anything in this document.
- Neither do the lurkers. You use it at your own risk.
-
- If you have other nuggets of knowledge which you'd like to share with your
- fellow lurkers, send us some mail!
-
- Video in General
-
- * Fields: Why Video Is Crucially Different from Graphics
- o Explains crucial video concepts and conventions
- * Definitions: F1/F2, Interleave, Field Dominance, and More
- o Defines F1, F2 for 525- and 625-line video standards
- o Explains how F1/F2 fields should be interleaved
- o Defines field dominance, explains why it matters
- o The terrible terms: "even" and "odd"
- o Defines related SGI Movie Library concepts
- * How Big Is Video?
- o How Many Bytes Per Pixel?
- o How Many Pixels In a Field or Frame?
- o How Many Bytes In a Field/Frame?
- o How Many Fields/Frames per Second?
- o How Many Bytes Per Second in Full-Rate Video?
-
- The VL
-
- * Displaying In-Memory Video Using OpenGL
- o How to make OpenGL glDrawPixels() go as fast as possible
- o Useful for VINO, ev3, cosmo2, Sirius, and many future boards
- * Displaying Video Using Galileo (ev1)
- o Setting up and maintaining an ev1 display
- * Tips for Writing Your Main (select, event) Loop
- o Explains what the VL file descriptors do
- o Avoiding common pitfalls when writing a VL select() loop
- o How to make it work if you're stuck with XtMainLoop()
- o Some caveats about spinloops
- o How to detect dropped or duplicated data correctly
- * Choosing an Input Jack
- o Ready-to-steal sample code for making this task as simple as it
- should be
- * Hints for Vid-to-Mem Applications
- o Video source node controls
- o Memory drain node controls
- o Handling preemption
-
- SGI Video Devices
-
- * Taxonomy of the ev1 and cosmo1 Boards
- o What are all those boards like Galileo Video, Indy Video, and
- Indigo2 Video, and how are they different?
- o What jacks do they have?
- o How does Cosmo Compress fit in?
- * Taxonomy of the ev3 and cosmo2 Boards
- o What is Impact Video?
- o What is Impact Compression?
- o What happened to ev2?
-
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- Send some feedback to your fellow Lurkers.
-