MPEG-FAQ 4.0:

What is MPEG-1+ ?

This was a little mail-talk between harti@shb.contrib.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@cs.tu-berlin.de