System for combining multiple audio channels into the baseband video signal and the recovery of the audio channels therefrom

A method for encoding a plurality of audio signal, representative of audio in different languages, which correspond to a single video signal, said plurality of audio signals being encoded within the bandwidth of standard format composite video signal prior to the translation of a baseband video signal into a modulated format used for conduction, transmission and recording of a video signal, said method comprising the steps of:

• allocating each audio signal representative of each language to a separate audio channel;
• modulating intermediate carrier signals by the audio signals of the audio channels, each audio signal modulating a different intermediate carrier signal of a different frequency;
• summing the modulated intermediate carrier signals;
• filtering a predetermined frequency from the baseband video signal to remove energy from the baseband video signal at the predetermined frequency;
• modulating a carrier signal by the summed modulated intermediate carrier signals, said carrier signal having a frequency equal to the predetermined frequency;
• inserting the modulated carrier signal at the predetermined frequency into the baseband video signal;
• whereby the audio signals representative of audio in different languages are encoded into the basebond video signal, thereby avoiding the addition of signals outside the baseband video signal and an increase in bandwidth of the signal, and the baseband video signal encoded with the audio signals can be subsequently conducted transmitted or recorded using unmodified video transmission or recording equipment.

An apparatus for encoding a pluarlity of audio signals, representative of audio in different languages, which correspond to a single video signal, said plurality of audio signals being encoded within the bandwidth of standard format composite video signal prior to the translation of a baseband video signal into a modulated format used for conduction, transmission or recording of a video signal, said apparatus comprising:

• a plurality of audio channels to receive the audio signals, each channel receiving one audio signal representative of the audio in a predetermined language;
• a filter to remove energy from the baseband video signal at a predetermined frequency;
• a first oscillator to produce a carrier signal having a frequency equal to the predetermined frequency;
• a first modulating means to modulate the carrier signal at the predetermined frequency, said carrier signal being modulated by the audio signals of the audio channels;
• and
• means for inserting the modulated carrier signal at the predetermined frequency into the baseband video signal;
• whereby the audio signals representative of audio in different languages are encoded into the baseband video signal, thereby avoiding the addition of signals outside the baseband video signal and an increase in bandwidth of the signal, and the baseband video signal encoded with the audio signals can be subsequently conducted, transmitted or recorded using unmodified video transmission or recording equipment.

An apparatus for encoding a plurality of audio signals, representative of audio in different languages, which correspond to a single video signal, said plurality of audio signals being encoded within the bandwidth of a standard format composite video signal prior to the translation of a baseband video signal into a modulated format used for conduction, transmission or recording of a video signal said apparatus comprising:

• a plurality of audio channels to receive the audio signals, each channel receiving one audio signal representative of the audio in a predetermined language;
• a plurality of first oscillators which produce a plurality of intermediate carrier signals at different frequencies;
• a first modulating means to modulate the intermediate carrier signals by the audio signals received by the audio channels, each audio signal modulating a different intermediate carrier signal;
• summing means to sum the modulated intermediate carrier signals;
• a filter to remove energy from the base band video signal at a predetermined frequency;
• a second oscillator which produces a carrier signal at the predetermined frequency;
• a second modulating means to modulate the carrier signal at the predetermined frequency, said carrier signal being modulated by the summed modulated intermediate carrier signals;
• means for inserting the modulated carrier signal at the predetermined frequency into the baseband video signal;
• whereby the audio signals representative of audio in different languages are encoded into the baseband video signal, thereby avoiding the addition of signals outside the baseband video signal and an increase in bandwidth of the signal, and the baseband video signal encoded with the audio signals can be subsequently conducted, transmitted or recorded using unmodified video transmission or recording equipment.