Digital information recording/reproducing method and apparatus
An apparatus and method for transmitting and receiving digital information includes a transmitting part for transmitting digital video information and digital audio information and receiving part for receiving digital video information and digital audio information. The transmitting part includes a first compressor for digital video information, a second compressor for digital audio information, a parity signal adder, a modulator, and a transmitter. The receiving part includes a receiver which receives digital information which is digital video information bit-compressed by a first compression system plus digital audio information bit-compressed by a second compression system, and to which has been added a parity signal for error detecting, phase-modulated and transmitted to a transmission path; a demodulator; an error detector, a first expander which bit-expands video information, and a second expander which bit-expands audio information.
1. An apparatus for transmitting and receiving digital information including a transmitting part for transmitting digital video information and digital audio information and receiving part for receiving digital video information and digital audio information:
wherein the transmitting part comprises:
a first compressor which bit-compresses digital video information by a first compression system;
a second compressor which bit-compresses digital audio information by a second compression system;
a parity signal adder which adds common parity signal for detecting an error to the digital video information and the digital audio information bit-compressed by the first compressor and the second compressor;
a modulator which phase-modulates the digital video information and the digital audio information, to which the parity signal has been added by the parity signal adder; and
a transmitter which transmits the digital video information and the digital audio information modulated by the modulator to a transmission path;
wherein the receiving part comprises:
a receiver which receives digital information which is digital video information bit-compressed by a first compression system plus digital audio information bit-compressed by a second compression system, and to which has been added a parity signal for error detecting, phase-modulated and transmitted to a transmission path;
a demodulator which demodulates the digital information received by the receiver corresponding to the phase-modulation;
an error detector which detects an error of the digital information demodulated by the demodulator by use of the parity signal;
a first expander which bit-expands video information corresponding to the first compression system, the video information being among the digital information error detected by the error detector; and
a second expander which bit-expands audio information corresponding to the second compression system, the audio information being among the digital information error detected by the error detector.
2. An apparatus for transmitting and receiving digital information in accordance with claim 1 , further comprising:
a first output terminal which outputs the digital video information expanded by the first expander; and
a second output terminal which outputs the digital audio information expanded by the second expander.
3. An apparatus for transmitting and receiving digital information in accordance with claim 1 , comprising:
a first D/A converter which coverts the digital video information expanded by the first expander to analog video information; and
a second D/A converter which converts the digital audio information expanded by the second expander to analog audio information.
4. An apparatus for transmitting and receiving digital information in accordance with claim 1 , wherein the first compression system and the second compression system are different systems from one another.
5. An apparatus for transmitting and receiving digital information in accordance with claim 1 , wherein the demodulator is a QPSK demodulator.
6. A method for transmitting and receiving digital information to transmit digital video information and a digital audio information and to receive digital video information and digital audio information, comprising the steps of:
a first compressing step which bit-compresses digital video information by a first compression system;
a second compressing step which bit-compresses digital audio information by a second compression system;
a parity signal adding step which adds a common parity signal for detecting an error to the digital video information and the digital audio information bit-compressed in the first and second compressing steps;
a modulating step which phase-modulates the digital video information and the digital audio information to which the parity signal has been added by the parity signal adding step;
a transmitting step which transmits the digital video information and the audio information modulated in the modulating step to a transmission path;
a receiving step which receives digital information which is digital video information bit-compressed by a first compression system plus a digital audio information bit-compressed by a second compression system, and to which has been added a parity signal for error detecting, phase-modulated and transmitted to a transmission path;
a demodulating step which demodulates the digital information received in the receiving step corresponding to the phase-modulation;
an error detecting step which detects an error of the digital information demodulated in the demodulating step by use of the parity signal;
a first expanding step which bit-expands video information corresponding to the first compression system, the video information being among the digital information error detected in the error detecting step; and
a second expanding step which bit-expands audio information corresponding to the second compression system, the audio information being among the digital information error detected in the error detecting step.
7. A method for transmitting and receiving digital information in accordance with claim 6 , further comprising:
a first outputting step which outputs the digital video information expanded in the first expanding step; and
a second outputting step which outputs the digital audio information expanded in the second expanding step.
8. A method for transmitting and receiving digital information in accordance with claim 6 , further comprising:
a first D/A converting step which converts the digital video information expanded in the first expanding step to analog video information; and
a second D/A converting step which converts the digital audio information expanded in the second expanding step to analog audio information.
9. A method for transmitting and receiving digital information in accordance with claim 6 , wherein the first compression system and the second compression system are different systems from one another.
10. A method for transmitting and receiving digital information in accordance with claim 6 , wherein the demodulation is a QPSK demodulation.
11. An apparatus according to claim 1 , further comprising:
an output terminal which outputs the digital information error-detected by the error detector to a recording/reproducing apparatus;
an input terminal which inputs a reproduced signal from the recording/reproducing apparatus; and
a selector which selects one of the digital information error-detected by the error detector and the digital information inputted from the input terminal;
wherein the digital information selected by the selector is bit-expanded by the first expander and the second expander.
12. An apparatus for transmitting and receiving digital information including digital video information and digital audio information, comprising:
a transmitting part for transmitting digital information; and a receiving part for receiving digital information;
wherein the transmitting part comprises:
a compressor which compresses digital information, the compressor including a time-compressor which time-compresses digital information and a bit-compressor which bit compresses digital video information by a first compression system and digital audio information by a second compression system;
a parity signal adder which adds a parity signal for detecting an error to the digital information compressed by the compressor;
a modulator which phase-modulates the digital information to which the parity signal has been added by the parity signal adder; and
a transmitter which transmits the digital information modulated by the modulator;
wherein the receiving part comprises:
a receiver which receives compressed digital information including compressed digital video information and compressed digital audio information;
a demodulator which demodulates the compressed digital information received by the receiver corresponding to the phase-modulation;
an error detector which detects an error of the digital information demodulated by use of the parity signal; and
an expander which expands the compressed digital information error detected by the error detector, the expander including a time-expander which time-expands the compressed digital information and a bit-expander which time-expands the compressed digital video information corresponding to the first compression system and the compressed digital audio information corresponding to the second compression system.
13. An apparatus for transmitting and receiving digital information in accordance with claim 12 , wherein a transmission rate of the digital information transmitted by the transmitter is lower than that of the digital information inputted into the compressor.
14. An apparatus for transmitting and receiving digital information including digital video information and digital audio information, comprising:
a transmitting part for transmitting digital information; and
a receiving part for receiving digital information;
wherein the transmitting part comprises:
a compressor which compresses digital information, the compressor including a time-compressor which time-compresses digital information; and
a bit-compressor which bit-compresses digital video information by a first compression system and digital audio information by a second compression system; and
a transmitter which transmits the digital information compressed by the compressor;
wherein the receiving part comprises:
a receiver which receives compressed digital information including compressed digital video information and compressed digital audio information; and
an expander which expands the compressed digital information received by the receiver, the expander including a time-expander which time-expands the compressed digital information and a bit-expander which time-expands the compressed digital video information corresponding to the first compression system and the compressed digital audio information corresponding to the second compression system.
15. An apparatus for transmitting and receiving digital information in accordance with claim 14 , wherein a transmission rate of the digital information transmitted by the transmitter is lower than that of the digital information inputted into the compressor.