Script to Create 2.35:1 Inverse "Burn-In" pattern for DVD

[Jhigh2000]

This sort of an experiment/proof of concept, but here's what I'm trying to accomplish (I don't have much experience with AviSynth):

I would like to create a script that will output several minutes worth of 2:35:1 AR content at 720x480 where the letterbox bars alternate between different colors and the main content is pure black. This is basically the inverse of a 2.35:1 anamorphic DVD.

The goal would be to burn the output to DVD and test what impact such a source would have on plasma television image retention after watching several 2:35:1 movies in a row, especially during the 0 to 500 hour break in period. In theory, displaying such a source for 15-20 minutes would help to even out the phosphor aging.

Here's what I have so far. Please help me optimize this script. All suggestions welcome!

base = BlankClip(length=720, width=720, height=480, fps=23.976, color=$000000)
A = Letterbox (base, 60, 60, 0, 0, $FFFFFF)
B = Letterbox (base, 60, 60, 0, 0, $CBCBCB)
C = Letterbox (base, 60, 60, 0, 0, $999999)
D = Letterbox (base, 60, 60, 0, 0, $C8EAFF)
E = Letterbox (base, 60, 60, 0, 0, $C9CEFF)
F = Letterbox (base, 60, 60, 0, 0, $969FFF)
G = Letterbox (base, 60, 60, 0, 0, $636EFF)
H = Letterbox (base, 60, 60, 0, 0, $3040FF)
I = Letterbox (base, 60, 60, 0, 0, $0010FF)
J = Letterbox (base, 60, 60, 0, 0, $FFFFFF)
K = Letterbox (base, 60, 60, 0, 0, $FEFBEE)
L = Letterbox (base, 60, 60, 0, 0, $FFD1CA)
M = Letterbox (base, 60, 60, 0, 0, $FFA496)
N = Letterbox (base, 60, 60, 0, 0, $FF887D)
O = Letterbox (base, 60, 60, 0, 0, $FF604B)
P = Letterbox (base, 60, 60, 0, 0, $FF472E)
Q = Letterbox (base, 60, 60, 0, 0, $FF1A00)
R = Letterbox (base, 60, 60, 0, 0, $FFFFFF)
S = Letterbox (base, 60, 60, 0, 0, $F7F7F7)
T = Letterbox (base, 60, 60, 0, 0, $C6F8C8)
U = Letterbox (base, 60, 60, 0, 0, $91F096)
V = Letterbox (base, 60, 60, 0, 0, $59E760)
W = Letterbox (base, 60, 60, 0, 0, $23E361)
X = Letterbox (base, 60, 60, 0, 0, $00D800)
Y = Letterbox (base, 60, 60, 0, 0, $FFFFFF)
Z = Letterbox (base, 60, 60, 0, 0, $DDDDDD)
AA = Letterbox(base, 60, 60, 0, 0, $F1F1F1)
A+B+C+D+E+F+G+H+I+J+K+L+M+N+O+P+Q+R+S+T+U+V+W+X+Y+ Z+AA

[guns1inger]

The first problem I see is that this will produce a clip with an aspect ratio of 4:3, containing a letterboxed image area with an aspect ratio of 1.78:1 (16:9). Is this what you intended ?

If you wanted a letterboxed image with an aspect ratio of 2.35:1 then you need to alter the letterbox statement to 96 instead of 60 (still in a 4:3 aspect ratio frame, or 56 if you want to encode this as 16:9 widescreen (still with a 2.35:1 image area).

You also need to add a trim statement to each line to set the number of frames the colour will hold for.

[Jhigh2000]

Thanks! I'll incorporate the changes you suggested.

Just so I understand correctly, originally my Letterbox() statement was using (..,58,64..) for the top/bottom bars. Here's how I got those numbers. I played a 2.35:1 DVD (Fight Club) in media player classic, paused it and exported a screenshot to bmp. I then opened the image and checked the dimensions. The top bar measured 720x58, the movie was 720x358 and the bottom bar measured 720x64. At the time this seemed right since 58+358+64 = 480 and since my goal was to "excersize" just the pixels that were black for the duration of this particular movie.

What are the problems with this approach?

Thanks again!