VBI Data on a Separate PID
The VBI data is packetized into MPEG-2 PES packets according to
ETSI ETS 300-472 for Teletext and ETSI EN 301 775 or SCTE 127 for all other VBI
data types. Closed caption data and aspect ratio signaling can also be inserted into
the compressed video elementary stream.
Timing
The VCM aligns the VBI data and the compressed video frames, i.e. it uses the
same PTS for the video and the VBI data if they are from the same frame.
B.3.6 Video
B.3.6.1 Pre-Processor Metrics
Production
The VCM pre-processor, in conjunction with the first stage ME, analyzes the video
on a macroblock by macroblock basis and produces Pre-Processor Metrics on:
• Activity - spatially
• Complexity
• Motion (vectors and SAD results)
• Luminance level
• Frame size information
Scene Cuts
Using the VCM Pre-Processor Metrics listed above, the pre-processor determines
scene cuts in the input video. This should cause the encoding engine to minimise
the effect of the scene change. This can shorten or lengthen the GOP. It is
configurable.
B.3.6.2 HD Video Formats
Active Video
The active video has either 1080 lines (interlaced) or 720 lines (progressive).
Video Resizing
The unit supports the input of video at 1920 x 1080i (25 Hz and 29.97 Hz) and
1280 x 720p (50 Hz and 59.94 Hz). The following sub-sampling of any input format
is supported.
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