Multichannel television sound stereo and surround sound encoder suitable for use with video signals encoded in plural formats

A method for generating a composite audio signal for transmission to a audio reproduction system from a video/audio signal generator, comprising the steps of:

• generating, using said video/audio signal generator, a left audio signal, a right audio signal and a video signal having a first signal embedded therein;
• determining if said video signal has a frequency that matches a predetermined frequency;
• generating a second signal having said predetermined frequency;
• producing a composite audio signal clocked to said first signal if the freqency of the first signal matches the predetermined frequency;
• and
• producing a composite audio signal clocked to said second signal if the freqency of the first signal differs from the predeteremined frequency.

A surround sound system, the system comprising:

• an audio reproduction system;
• a video/audio signal generator;
• an audio adapter coupling said video/audio signal generator to said audio reproduction system;
• a first audio input for receiving a left audio signal from said video/audio signal generator;
• a second audio input for receiving a right audio signal from said video/audio signal generator;
• an audio signal processor, coupled to said first and second audio inputs, said audio signal processor generating a composite audio signal clocked to a selected frequency for output to said audio reproduction system;
• a video input for receiving a primary video signal from said video/audio signal generator, said primary video signal having a first signal embedded therein;
• an internal signal source having an output, said internal signal source generating a secondary signal having a frequency of which matches said selected frequency;
• and
• a switch for selectively coupling said video input or said output of said internal signal source to said audio signal processor whenever the frequency of the first signal fails to match said selected frequency;
• said audio signal processor clocking said composite audio signal to the frequency of said first signal when said video input is coupled to said audio signal processor and clocking said composite audio signal to the frequency of said secondary signal when said secondary signal is coupled to said audio signal processor.

A method for generating a composite audio signal for transmission to a audio reproduction system from a video/audio signal generator, comprising the steps of:

• generating, using said video/audio signal generator, a left audio signal, a right audio signal and a video signal having a first signal embedded therein;
• determining if said video signal has a frequency that matches a predetermined frequency;
• generating a second signal having said predetermined frequency, wherein the second signal is a horizontal synchronization signal and the predetermined frequency is greater than 15.7 KHz;
• producing a composite audio signal clocked to said first signal if the frequency of the first signal matches the predetermined frequency;
• and
• producing a composite audio signal clocked to said second signal if the frequency of the first signal differs from the predetermined frequency.