Method for simultaneously delivering ATSC/MPEG source material to dual modulated RF television outputs
A single electronic device is disclosed that splits a transport stream in order to simultaneously produce NTSC and ATSC standard outputs with the same video and audio content so that the same content can be viewed side-by-side on a standard definition NTSC television and an ATSC digital HDTV set at the same time.
1. A method of simultaneously delivering ATSC/MPEG source material to dual modulated RF television outlets, comprising the steps of:
reading and storing an MPEG transport stream;
splitting said transport stream and simultaneously feeding same into an 8-VSB modulator and an MPEG decoder;
converting said one of said split transport stream fed into said 8-VSB modulator to an 8 level VSB signal;
decoding said other of said split transport stream into baseband audio and video signals, and
amplitude modulating said video signal and frequency modulating said audio signal.
2. The method as defined in claim 1 further including the steps of,
up-converting said 8 level VSB signal to an RF frequency, and
up-converting said modulated audio and video signals to an RF frequency.
3. The method as defined in claim 2 further including the steps of,
amplifying and filtering said up-converted 8 level VSB signal and outputting same as an ATSC 8-VSB RF signal, and
amplifying and filtering said up-converted modulated audio and video signals and outputting same as an NTSC RF signal.
4. The method as defined in claim 1 further including the step of,
adding a signal delay in an NTSC path at the MPEG decoder step equal to the amount of longer internal delays in an ATSC receiver.