Line 23 signalling

The main purpose of the signalling information of Line 23 is to inform a new generation TV on the actually transmitted aspect ratio. The automatic adaptation to the broadcast format could be one important feature of CTV set generations and will avoid manual switching as required for today's 16:9 TV sets. Subtitle information will be transmitted to inform about subtitle status which may be broadcast in several combinations with different aspect ratios. Line 23 provides capacity for transmitting information for future enhanced TV-service, e.g. PAL plus. Some bits are reserved for future extensions.<
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