T42 packet stream

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A t42 packet stream is simply a sequence of teletext packets minus the clock run-in and framing code.

The 42 bytes (two byte MRAG and 40 characters/bytes) are encoded as they would be for transmission. i.e the t42 stream contains all parity and hamming coding etc.

A t42 file may represent a full teletext service stream, packets for a single page, or anything in between. That is to say there is no specific structure to what a stream will contain, so it must be decoded as a receiver would decode a live transmission to extract any particular pages or data packets of interest.