Sony DVP-NS999ES - Manual (Page 48)

ES Series DVD-Video/CD/SA-CD Players; Version 3.0 Page 48
The 24P encoding of film-originated DVDs means that 3-2 pulldown must
be performed in the DVD player before the picture can be displayed on a
conventional television. The exact pattern of 3-2 pulldown can have a subtle
effect on the rendering of motion. So it's important that the DVD reproduce the 3-
2 pulldown cadence of the original master videotape. That's where the FFRFs
come in. They identify each field to be repeated as part of a "3."
Interlace-to-progressive (I/P) conversion
The playback of 480/24P film-originated material has a special property.
In material originally shot on 480/60i video, each "B" field represents a slice of
time 1/60th second after the corresponding "A" field. To the extent that objects in
the frame are moving, the two fields won't match and aren't well suited for direct
output in progressive scan.
In contrast, 480/24P film-originated DVD is inherently progressive and is
beautifully suited to progressive scan display. Ironically, most of today's MPEG
decoder chips automatically convert the 480/24P progressive DVD into 480/60i
interlaced video. Additional processing is required to convert the 480/60i
interlaced signal into a 480/60P progressive signal for output to a compatible
television. The required process is called interlace-to-progressive (I/P)
conversion. Because the process operates on a digital signal in the digital
domain, it can result in a super high-quality video source that promises to be the
ideal complement to high-end, big-screen televisions with 480P inputs.
Frame memory versus full 3-2 reverse conversion
Unfortunately, not every DVD player with 480P outputs fully delivers on
the promise. One potential way to cut corners in 480P output is to adopt
relatively inexpensive frame memory. However, simple frame memory systems
can expose the signal to motion blur on two out of every five video frames. You
can see a zipper-like artifact on the left and right side of moving objects.
The cause of these artifacts becomes clear when we review the I/P
conversion process. In simple frame memory conversion, the player combines
consecutive pairs of fields—no matter what cinema frame they came from. If the
two fields came from the same cinema frame, all is well and a beautiful 480P
picture results. But if the two fields came from different cinema frames—an
event that regularly occurs two times out of five—then images that were captured
1/24 second apart will be artificially combined on the television screen. The
result will be a blur of any moving objects in the video picture. These problems
are so severe that they undermine the whole reason for getting a progressive
scan DVD player in the first place.