Wisi Chameleon - HD to SD Downscaling and Dual Mono

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AFD (Active Format Description)
The AFD describes the portion of the coded video frame that is "of interest". It is intended for use in networks that
deliver mixed formats to a heterogeneous receiver population. The format descriptions are informative in nature
and are provided to assist receiver systems to optimize their presentation of video.
Chameleon handles a sub-set of the AFD codes defined in ETSI TS 101 154;
• 1000 (8) as coded frame
• 1001 (9) 4:3 active picture
• 1010 (10) 16:9 active picture
The received AFD signalling will be used for calculating the outgoing WSS signalling if the WSS configuration is set
to Auto, and the Video conversion to Auto or Letterbox. Please note that there is no specific setting in the
Chameleon for AFD.
An example of AFD usage is when the source video has aspect ratio 16:9, but the AFD is signalling that the active
part of the video frame is “the middle 4:3 part”. The resulting calculated WSS signalling allows 4:3 TV sets to
display the active part of the video frame over the whole display. If AFD is not taken into account, the 16:9 frame
with black left and right bars would be letterboxed to “stamp” size for 4:3 TV sets.
AFD 9, AR 16:9
WSS 4:3 Full
WSS 16:9 Letterbox
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9.4 HD to SD downscaling and Dual mono
This chapter only relates to operation modes PAL-625/SELAM and PAL-M/NTSC.
Important information about HD to SD downscaling
The MPEG decoder can downscale one service from MPEG2/4 HD to SD. When using the MPEG decoder for
downscaling, you are limited to 1 analogue output.
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Dual mono output
It is possible to set up one analogue output with dual mono sound (different languages in left/right audio channel).
The main application for Dual mono out is to provide access to different audio languages for the same video
output.
1. Create 2 analogue outputs
2. Set up both decoders with the same service but different audio languages
3. Select Stereo mode: Dual mono
4. Deactivate the second analogue output (Output enabled = OFF)
5. In the Modulator settings, select Audio system A2 Dual mono or NICAM Dual mono
6. Select Dual mono source: Both decoders
The Dual Mono out is generic in the sense that you can select different services for decoder 1 and decoder 2, and
get the selected audio stream as “mono 1” and “mono 2” in the receiver.