12th Annual Video Review of Computational Geometry

NTSC Video Recommendations

Accepted videos will be compiled onto an NTSC DVD, which should play on NTSC DVD players, PAL DVD players, and computer DVD drives. The lowest common denominator of these outputs is NTSC, so you should prepare your video for that.

Hard requirements:

  1. Resolution: 720x480
    (PowerPoint presentations will be rendered at 640x480; please test them at that resolution.)

  2. Framerate: 29.97 frames per second
    (You can use a lower framerate only if your video looks alright.)

  3. High quality: Use a minimally lossy codec for both video and audio; large files are desired. Do not use MPEG-1.
Soft requirements (strong desires):
  1. Margins: Anything that has to be seen in your video should be within a 5% border on all sides (about 36 pixels from each side and 24 pixels from the top and bottom). This is important for watching your video on a TV, and applies to PowerPoint presentations as well.

  2. Line thickness: Whenever possible, use reasonably thick lines (at least 2 or 3 pixels); do not use 1-pixel lines. (A combination of low-resolution TVs and interlacing can make thin lines, especially horizontal lines, flicker or otherwise hard to see.)

  3. Text size: Use text that's as large as possible (to improve readability), and ideally also a bold font (to avoid thin lines).

  4. Anti-alias: Anti-alias lines and text if possible (to avoid the sharp color contrast, which would otherwise cause a ghost or in extreme cases an audio buzz). A good value is a gaussian blur of between 0.2 and 1.0 pixels. PowerPoint anti-aliases most objects automatically, but do make sure your text and lines are large and thick enough when rendering at 640x480.

  5. Color: NTSC TVs do all sorts of crazy things with color. If possible, test out your video on an NTSC TV to spot any problems. Avoid saturated colors, especially red, because they bleed. Avoid cross-hatching and dithering.

    More precisely, NTSC video supports a luma range of 16 to 235 (in YUV space); so your RGB values should be between 16 and 235 (instead of the usual 0 to 255). A rule of thumb for avoiding saturated colors is to use values no higher than 180; and for red, there may still be bleeding lower than 180. Despite the darker look on screen, these colors will look better on NTSC video.

If you're interested, you can read some reasoning behind these recommendations.