dmpeg zip info another dos mpeg decoder player posted i have posted a dos mpeg decoder player to alt binaries pictures utilities here is a short description and some technical information taken from the accompanying documentation dmpeg v public domain mpeg decoder by stefan eckart features dmpeg dmplay is another mpeg decoder player for the pc decodes nearly the full mpeg video standard i p b frames frame size up to at least x supported saves decoded sequence in or bit raw file for later display optional on screen display during decoding requires vga several dithering options ordered dither floyd steinberg grayscale color space selection runs under dos kb ram no ms windows required very compact small code small data models bit arithmetic real time display of the raw file by a separate player for vga and many super vgas technical information the player is a rather straightforward implementation of the mpeg spec the idct is based on the chen wang multiplication algorithm not quite the optimum i know blocks with not more than eight non zero coefficients use a non separated direct multiply accumulate d idct sounds great doesn t it which turned out to be faster than a fast algorithm in this quite common case dithering is pretty standard main difference to the berkeley decoder except for the fewer number of supported algorithms is the use of instead of colors the default option to use a restricted color space and the implementation of a color saturation dominant ordered dither this leads to a significantly superior quality of the dithered image i claim judge yourself restricted color space means that the u and v components are clipped to instead of and the display color space points are distributed over this restricted space since the distance between color space points is thus reduced by a factor of two the color resolution is doubled at the expense of not being able to represent fully saturated colors saturation dominant ordered dither is a method by which a color lying somewhere between the points of the display color space is approximated by primarily alternating between two points of constant hue instead of constant saturation this yields subjectivly better quality due to the lower sensitivity of the human viewing system to saturation changes than to hue changes the same reasoning as used by the pal tv standard to improve on ntsc the improvement is particularly visible in dark brown or redish areas stefan eckart stefan lis e technik tu muenchen de
