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06-14-2005, 08:46 AM
What do Pull Down 3:2 and Pull Down 4:4:4 in DVD players mean ?
Can someone help me ? Thanks

06-14-2005, 09:58 AM
3:2 pulldown refers to a DVD player's ability to convert the 24 frame per second material of film into our 60 field per second display standard. If you do the math of 24/60, you'll find that every four frames of film require ten fields of NTSC video to come out even. The sequence that the player produces for each frame is (1) three repeated fields--(2) two repeated fields--(3) three repeated fields--(4) two repeated fields. Thus do the four film frames convert to our standard frequency.

4:4:4 sampling refers to MPEG decoding of black/white (lumina) and color information (chroma). It represents the best possible sampling, in which both lumina (Y) and the two color components (Pb and Pr) are sampled at the same rate. At this sampling rate, the Chroma Upsampling Bug (CUE) doesn't occur, but this kind of upsampling is rare and unnecessary. Since the eye isn't as sensitive to color as it is to light, 4:2:2 sampling--meaning color getting only half the samples of black and white--usually suffices.

This is the short answer. Players vary in their ability to do such decoding, depending on the chips that they use.