Method and apparatus for transmitting and receiving digital video and audio information
A method and apparatus for transmitting and receiving digital information including video information and audio information. The video information is compressed by a first compression method and the audio information is compressed by a different second compression method for transmission on a transmission path.
1. A method for transmitting and receiving digital information which includes digital video information and digital audio information so as to transmit and to receive the digital video information and the digital audio information, comprising:
a compressing step which compresses the digital information by bit-compressing the digital video information by a first compression method and by bit-compressing the digital audio information by a second compression method which is different from the first compression method, and by time-compressing the digital video information and digital audio information;
a parity signal adding step which adds a parity signal for detecting an error to the digital information compressed by the compressing step, the error being the error occurring in a transmission path and not in a recording process of the digital information;
a modulating step of phase shift-keying-modulating the digital information to which the parity signal has been added by the parity signal adding step;
a transmitting step which transmits the digital information modulated by the modulating step to the transmission path;
a receiving step which receives the compressed digital information from the transmission path including the compressed digital video information and the compressed digital audio information;
a demodulating step which demodulates the compressed digital information received in the receiving step corresponding to the phase shift keying-modulation;
an error detecting step which detects an error of the compressed digital information demodulated in the demodulating step by use of the parity signal, the error being the error occurring in the transmission path and not in the recording process of the digital information; and;
an expanding step which expands the compressed digital information error-detected by the error detecting step by bit-expanding the compressed video information corresponding to the first compression method and by bit-expanding the compressed audio information corresponding to the second compression method; and
wherein a transmission rate of the digital information transmitted by the transmitting step is lower than that of the digital information inputted in the compressing step.
2. An apparatus for transmitting and receiving digital information, comprising:
a transmitting part for transmitting digital information to a transmission path; and
a receiving part for receiving digital information from the transmission path;
wherein the transmitting part comprises:
a compressor configured to compress digital information of a program including digital video information and digital audio information, the compressor including a bit-compressor configured to bit-compress the digital video information of the digital information by a first compression method and to bit-compress the digital audio information of the digital information by a second compression method which is different from the first compression method, and a time-compressor configured to time-compress the digital video information and the digital audio information;
a parity signal adder configured to add a parity signal to the digital information for detecting an error of the digital information compressed by the compressor, the error being the error occurring in the transmission path and not in a recording process of the digital information;
a modulator configured to phase shift keying-modulate the digital information to which the parity signal has been added by the parity signal adder; and
a transmitter configured to transmit the digital information modulated by the modulator to the transmission path;
wherein the receiving part comprises:
a receiver configured to receive the compressed digital information from the transmission path including the compressed digital video information and the compressed digital audio information;
a demodulator configured to demodulate the compressed digital information received by the receiver corresponding to the phase shift keying-modulation;
an error-detector configured to detect an error of the compressed digital information demodulated by the demodulator, by use of the parity signal, the error being the error occurring in the transmission path and not in the recording process of the digital information; and
an expander configured to expand the compressed digital information error-detected by the error detector, the expander including a bit-expander configured to bit-expand the compressed digital video information corresponding to the first compression method and to bit-expand the compressed digital audio information corresponding to the second compression method;
wherein a transmission rate of the digital information transmitted by the transmitter is lower than that of the digital information inputted into the compressor.
3. The apparatus for transmitting and receiving digital information according to claim 2 , wherein the expander includes a time-expander configured to time-expand the compressed digital information.
4. An apparatus for transmitting and receiving digital information, comprising:
a transmitting part for transmitting digital information to a transmission path; and
a receiving part for receiving digital information from the transmission path;
wherein the transmitting part comprises:
a compressor configured to compress digital information of a program including digital video information and digital audio information, the compressor including a bit-compressor configured to bit-compress the digital video information of the digital information by a first compression method and to bit-compress the digital audio information of the digital information by a second compression method which is different from the first compression method, and a time-compressor configured to time-compress the digital video information and the digital audio information;
a parity signal adder configured to add parity signals to the digital information for detecting an error to the digital information compressed by the compressor, the error being the error occurring in the transmission path and not in a recording process of the digital information, the parity signals being added to both the compressed digital video information and the compressed digital audio information;
a modulator configured to phase-modulate the digital information to which the parity signals have been added by the parity signal adder; and
a transmitter configured to transmit the digital information modulated by the modulator to the transmission path;
wherein the receiving part comprises:
a receiver configured to receive the compressed digital information from the transmission path including the compressed digital video information and the compressed digital audio information;
a demodulator configured to demodulate the compressed digital information received by the receiver corresponding to the phase-modulation;
an error-detector configured to detect an error of the compressed digital information demodulated by the demodulator, by use of the parity signals added to both the compressed digital video information and the compressed digital audio information, the error being the error occurring in the transmission path and not in the recording process of the digital information; and
an expander configured to expand the compressed digital information error-detected by the error detector, the expander including a bit-expander configured to bit-expand the compressed digital video information corresponding to the first compression method and to bit-expand the compressed digital audio information corresponding to the second compression method;
wherein a transmission rate of the digital information transmitted by the transmitter is lower than that of the digital information inputted into the compressor.
5. The apparatus for transmitting and receiving digital information according with claim 4 , wherein the phase-modulation is a QPSK-modulation.
6. The apparatus for transmitting and receiving digital information according to claim 4 , wherein the expander includes a time-expander configured to time-expand the compressed digital information.
7. An apparatus for transmitting and receiving digital information, comprising:
a transmitting part for transmitting digital information to a transmission path; and
a receiving part for receiving digital information from the transmission path;
wherein the transmitting part comprises:
a compressor configured to compress digital information of a program including digital video information and digital audio information, the compressor including a bit-compressor configured to bit-compress the digital video information of the digital information by a first compression method and to bit-compress the digital audio information of the digital information by a second compression method which is different from the first compression method, and a time-compressor configured to time-compress the digital video information and the digital audio information;
a parity signal adder configured to add parity signals to the digital information for detecting an error of the digital information compressed by the compressor, the error being the error occurring in the transmission path and not in a recording process of the digital information, the parity signals being added to both the compressed digital video information and the compressed digital audio information; and
a transmitter configured to transmit the digital information to which the parity signals have been added by the parity signal adder to the transmission path;
wherein the receiving part comprises:
a receiver configured to receive the compressed digital information from the transmission path including the compressed digital video information and the compressed digital audio information;
an error-detector configured to detect an error of the compressed digital information received by the receiver, by use of the parity signals added to both the compressed digital video information and the compressed digital audio information, the error being the error occurring in the transmission path and not in the recording process of the digital information; and
an expander configured to expand the compressed digital information error-detected by the error detector, the expander including a bit-expander configured to bit-expand the compressed digital video information corresponding to the first compression method and to bit-expand the compressed digital audio information corresponding to the second compression method;
wherein a transmission rate of the digital information transmitted by the transmitter is lower than that of the digital information inputted into the compressor.
8. The apparatus for transmitting and receiving digital information according to claim 7 , wherein the expander includes a time-expander configured to time-expand the compressed digital information.
9. An apparatus for transmitting digital information to a transmission path, comprising:
a compressor configured to compress digital information of a program including digital video information and digital audio information, the compressor including a bit-compressor configured to bit-compress the digital video information of the digital information by a first compression method and to bit-compress the digital audio information of the digital information by a second compression method which is different from the first compression method, and a time-compressor configured to time-compress the digital video information and the digital audio information;
a parity signal adder configured to add a parity signal to the digital information for detecting an error of the digital information compressed by the compressor, the error occurring in the transmission path and not in a recording process of the digital information;
a modulator configured to phase shift key-modulate the digital information to which the parity signal has been added by the parity signal adder; and
a transmitter configured to transmit the digital information modulated by the modulator to the transmission path;
wherein a transmission rate of the digital information transmitted by the transmitter is lower than that of the digital information inputted into the compressor.
10. An apparatus for transmitting digital information to a transmission path, comprising:
a compressor configured to compress digital information of a program including digital video information and digital audio information, the compressor including a bit-compressor configured to bit-compress the digital video information of the digital information by a first compression method and to bit-compress the digital audio information of the digital information by a second compression method which is different from the first compression method, a time-compressor configured to time-compress the digital video information and the digital audio information;
a parity signal adder configured to add parity signal to the digital information for detecting an error of the digital information compressed by the compressor, the error occurring in the transmission path and not in a recording process of the digital information, the parity signals being added to both the compressed digital video information and the compressed digital audio information;
a modulator configured to phase-modulate the digital information to which the parity signals have been added by the parity signal adder; and
a transmitter configured to transmit the digital information modulated by the modulator to the transmission path;
wherein a transmission rate of the digital information transmitted by the transmitter is lower than that of the digital information inputted into the compressor.
11. The apparatus for transmitting digital information according to claim 10 , wherein the phase-modulation is a QPSK-modulation.