I adapted Geek Thoughts‘ “Making Noise with ImageMagick” in creating video noise — a video simulating what you used to get when you turned on a television with no signal, back in the analog days. To combine the noise frames created by ImageMagick I used Netpbm, which I had to install separately (that is, it wasn’t installed by default in Lenny).
Here’s the Bash multi-liner I used to generate 48 frames worth of noise:
(for i in `seq 1 48`; \ do convert -size 640x480 xc: +noise Random \ -blur 1x1 -fx intensity -normalize ppm:-; done) \ | ppmtompeg kohina.txt
kohina.txt which specifies how ppmtompeg packs the frames. Note that I just threw this together without too much thought, so it definitely needs tweaking depending on what the video is used for and so what (quality, compression, speed) matters. For example, I only used I-frames due to lack of imagination.
PATTERN IIIIIIII OUTPUT kohina.mpeg INPUT_DIR stdin BASE_FILE_FORMAT PPM INPUT_CONVERT * GOP_SIZE 8 SLICES_PER_FRAME 30 PIXEL HALF RANGE 2 PSEARCH_ALG LOGARITHMIC BSEARCH_ALG SIMPLE IQSCALE 1 PQSCALE 1 BQSCALE 1 REFERENCE_FRAME ORIGINAL
And here’s what it looks like, recompressed with Theora (using Oggconvert):
kohina.ogg (2,8 MB). Generating an accompanyng soundtrack is trivial with Audacity.