Video/audio simultaneous transmission system
AssigneesNippon Electric Co., Ltd., Nippon Telegraph & Telephone Public Corporation, Fujitsu Limited
InventorsHaruo Shimoyama, Toshio Ohshima, Shinobu Nomoto, Makoto Hiraoka, Toshio Hanabata
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Abstract
The horizontal sync signal contained in the video signal from a video apparatus sometimes undergoes phase jump, resulting in failure of multiplexing of audio and video signals based on the horizontal sync signal. A sync signal switching circuit is adapted to produce a modified sync signal by switching the sync signal to a local sync signal upon occurrence of the phase jump, thereby assuring the multiplexing of audio and video signals.
Claims3
A video/audio simultaneous transmission system comprising:
- means for sampling and encoding a video signal inclusive of horizontal sync signals occurring at indefinite time intervals in response to a first clock signal having a recurrence period independent of the recurrence period of the horizontal sync signal;
- means for sampling and encoding an audio signal in response to a second clock signal having a predetermined recurrence period;
- means for generating a sync signal in response to the horizontal sync signal;
- means for modifying the sync signal to produce a modified sync signal on the basis of said first clock signal;
- and
- means responsive to a third clock signal each time it receives the modified sync signal, for transmitting a special code different from the codes of the encoded audio and video signal data and thereafter the encoded audio and video signals successively.
Dependencies are inferred from the claim text.