61 What is MPEG-1+ ?
Description
This article is from the MPEG FAQ, by Frank Gadegast phade@cs.tu-berlin.de with numerous contributions by others.
61 What is MPEG-1+ ?
This was a little mail-talk between harti@harti.de (Stefan Hartmann)
and hgordon@system.xingtech.com.
Q: What is MPEG-1+ ?
It's MPEG-1 at MPEG-2 (CCIR) resolution. It will maybe be used
fir TV-on-top-boxes for broadcasting or video-on-demand projects
to enhance the picture quality.
Q: I see. Is this a new standard ?
No. MPEG-1 allows the definition of frames until 4000x4000 pixel, but
that is usally not used.
Q; So what's different ?
I understand that the effective resolution is approximately 550 x 480.
Typical datarates are 3.5Mbps - 5.5Mbps (sports programming and perhaps
movies are higher).
Q: Is the video quality lower than with real MPEG-2 movies ?
The quality is better than cable TV, and in my area, we don't have cable.
They de-interlace and compress the full frames. My understanding is that
this is about 5%-10% less efficient than taking advantage of MPEG-2
interfield motion vectors.
Q: If the fields are deinterlaced, do you see the interlace artifacts, so that
a moving object in one field is already more into one direction, than in the
other field ?
Probably the TV-receiver also gives it out interlaced again to the TV-
set, so this does not produce this interlace artifact like on
PCs with live video windows displaing both fields....
Q: Can you record this anyhow on a VCR ? Does the SAT-Receiver have a
video- output, so you can record movies to tape ?
You should be able to record to tape, though they may have some record
blocking hardware which has to be overcome with video stabilizing
hardware.
Q: What kind of realtime encoders do they use at the broadcast station ?
CLI (Compression Labs) is the manufacturer, using C-Cube chipsets (10
CL-4000's per MPEG-1+ encoder).
Q: Is there any written info about this MPEG-1 Plus technology available on
the net ?
Not that I'm aware. Maybe C-Cube has a Web site.
[So it's up to you, dear reader, to find more and to tell me where it is ;o) ]
Frank Gadegast, phade@powerweb.de
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