Alaris VideoGramPiX
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- FourCCs: VGPX
- Company: Alaris
Sample Java player available here: http://www.ila-ila.com/xvd-hist/sites/vgram/index.htm
The codec works by reading a code for an operation using a codebook and performs some action on pixels (RGB triplets in this case) depending on it (usually copy, skip or average):
- 0 - skip current pixel
- 1 - copy left pixel value
- 2 - copy top pixel value
- 3 - copy right pixel value
- 4 - copy bottom pixel value
- 5 - set pixel to an average of top and left pixels
- 6 - set pixel to an average of top and right pixels
- 7 - set pixel to an average of bottom and right pixels
- 8 - set pixel to an average of bottom and left pixels
- 9 - read a code for pixel difference (each codebook entry has differences for every component)
- 10 - skip a number of pixels the number of times defined in frame header
- 11 - repeat left pixel value the number of times defined in frame header
Something similar can be found in an alternative frame coding method for VT codec of VGM Video family.