The more the better.
The higher the quality or rate of the incoming video, the higher the quality of the MPEG2 compressed video will be. That output can be varried with the type of programing...(ie. action sports have more movement than talk shows therefore requiring more bandwidth)
It is my understanding that VBR..or variable bit rate encoding is what seperates the men from the boyz.
For nuts and bolts numbers look here:
c-cube.com
Flexibility for High Definition
High-level (HL@MP) MPEG-2 applications such as HDTV encoding require two to eight times more processing power than do main-level (ML@MP) broadcast applications like direct broadcast satellite. The "MP" in the ML@MP specification stands for Main Profile, indicating that standard MPEG2 techniques, such as chroma decimation and the use of B frames, are allowed. The different levels and profiles of MPEG2 encoding are shown in Table 1. Simple Main SNR Spatial High
High 1920 x 1152
I, B, P
4:2:0
80 Mb/sec
60 fps 1920 x 1152
I, B, P
4:2:0 or 4:2:2
100 Mb/sec
60 fps
High 1440 1440 x 1152
I, B, P
4:2:0
50 Mb/sec
60 fps 1440 x 1152
I, B, P
4:2:0
60 Mb/sec
60 fps 1440 x 1152
I, B, P
4:2:0 or 4:2:2
80 Mb/sec
60 fps
Main 720 x 576
I, P
4:2:0
15 Mb/sec
30 fps 720 x 576
I, B, P
4:2:0
15 Mb/sec
30 fps 720 x 576
I, B, P
4:2:0
15 Mb/sec
30 fps 720 x 576
I, B, P
4:2:0 or 4:2:2
20 Mb/sec
30 fps
Low 352 x 288
I, B, P
4:2:0
4 Mb/sec
30 fps 352 x 288
I, B, P
4:2:0
4 Mb/sec
30 fps
Table 1. MPEG-2 Levels and Profiles
|
