Because of limitations in the RoQ format and Quake 3 and Doom 3 engine games,
you MUST follow these rules:

Input videos MUST BE 30 FRAMES PER SECOND.

Input video dimensions MUST BE DIVISIBLE BY 16

Input video dimensions MUST BE LESS THAN 65536

If you want to play your video back in a Quake 3 engine game, then
  input video dimensions MUST BE POWERS OF TWO.  This means 16, 32,
  64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, or 32768.

Audio may be 11025 Hz, 22050 Hz, or 44100 Hz, any number of bits,
BUT IT WILL BE ENCODED AS 22050 HZ 16-BIT REGARDLESS OF WHAT YOU
DO, so it is a good idea to make your input audio those settings.

If you are muxing from an AVI file, it must be 16 bit.



If you need to prep your videos, you can use VirtualDub, which is a free video
tool you can get at http://www.virtualdub.com/

INSTRUCTIONS FOR PREPARING A VIDEO WITH VIRTUALDUB:

1. File -> Open video file...
   Select your source video

2. Video -> Frame Rate...
   Check "Convert to fps:" and put 30 in the box

3. Video -> Filters...
   Add...
   Select "resize"
   Enter the new dimensions for your video.  Most Quake 3 videos
      use 512 x 256.  If you want more detail, use 512 x 512.
   Filter mode should be "Bilinear" or "Precise bilinear"
   Click "OK" in the filter settings window
   SEE THE NOTES AT THE END ABOUT ASPECT RATIO IF YOU'RE PLANNING
      TO ENCODE A FULL-SCREEN VIDEO
   Click "OK" in the filter list window

4. Audio -> Full processing mode

5. Audio -> Conversion...
   Select 22050Hz
   Check "High quality"
   Leave other settings alone or change to your liking

6. Video -> Compression...
   Pick a high-quality codec.  DivX or VP are recommended, but
   Indeo Video will suffice at high quality settings.
   Do not use Cinepak.
   DIRECTSHOW-ONLY CODECS ARE NOT SUPPORTED.  XviD, for example, will not work.


7. Video -> Save as AVI...
   Save it somewhere.  Don't overwrite the original.


VirtualDub can be downloaded FREE at http://www.virtualdub.com/



ASPECT RATIO
   Quake 3 videos are automatically scaled to match your screen
dimensions most of the time.  Well great... except that means your
video can get stretched or compressed if it's not the right aspect
ratio.  To make sure your aspect ratio stays the same for full
screen video, do this:

Open Calculator

Enter your source video's width
Click /
Enter your source video's height
Click =

IF THE RESULTING NUMBER IS NOT 1.3333333333333333333, etc.
  THEN YOUR ASPECT RATIO IS OFF, AND YOU NEED TO LETTERBOX YOUR
  VIDEO OR IT WILL NOT COME OUT RIGHT.



To fix the aspect ratio, first click Add... and select "resize"
Check the "Expand frame and letterbox image" box.
Fill in the "New width" and "Frame width" fields with your
  movie's width
Fill in the "New height" and "Frame height" fields with your
  movie's height

Go back to Calculator

If the number is HIGHER than 1.3333333:
   Enter your source video's width
   Click *
   Enter 0.75, then click =

   Replace the "Frame height" field with that number (before
     the decimal point if there is one)


If the number is LOWER than 1.33333333:
   Enter your source video's height
   Click /
   Enter 0.75, then click =

   Replace the "Frame width" field with that number (before
     the decimal point if there is one)


Now click OK, then click Move Up to move the filter up the list
