Super Video-CD
NTSC Film
MPEG-2
480x480
23.976fps
CBR 2520kbps
Layer-2 44100Hz 224kbps
Super Video-CD
PAL
MPEG-2
480x576
25fps
CBR 2520kbps
Layer-2 44100Hz 224kbps
The MPEG 2 specification (ISO 13818) was designed for
broadcast TV and others using interlaced images. It gives
higher picture quality than MPEG 1 but using a higher data
rate. At lower bit rates, there is no point in using MPEG 2
over MPEG 1. At bit rates above 4 Mbits/s MPEG 2
should be used instead of MPEG 1. Unlike MPEG 1, MPEG 2
supports interlaced TV systems and Vertical Blanking
Interval signals.
MPEG 2 also includes higher audio quality and can use
surround sound with 5.1 channels. You can also use a
variable video bit rate (VBR) for the audio. Broadcast
applications, currently using MPEG-2, generally use around 7
Mb/s fixed data rate.
MPEG 2 uses the same frame types as MPEG 1 except that
each frame comprises two interlaced fields. Also each group
of pictures (GOP) is 15 (PAL) or 18 (NTSC) frames in length.
I B P B P B P ie there is only one B-frame between
P-frames instead of two for MPEG 1.
As Stored on Disk
As Displayed
Each macroblock of a B-frame is coded as a change from
the previous or next P-frame or I-frame. The I-frames are
repeated at approximately 0.5 second intervals, otherwise
the PBPBP.. pattern is repeated indefinitely.
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