Digital information recording/reproducing apparatus
An apparatus for at least receiving digital information including digital video information bit-compressed by a first compression system plus digital audio information bit-compressed by a second compression system and transmitted to a transmission path. The receiver apparatus includes a receiver which receives the transmitted digital information, a demodulator which demodulates the digital information received by the receiver, an error detector which detects an error of a digital information demodulated by the demodulator by use of a parity signal, a first expander which bit-expands video information among digital information error detected by the error detector corresponding to the first compression system and a second expander which bit-expands audio information among digital information error detected by the error detector corresponding to the second compression system.
1. An apparatus for receiving 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 transmitted to a transmission path, comprising:
a receiver which receives the transmitted digital information;
a demodulator which demodulates the digital information received by the receiver;
an error detector which detects an error of digital information demodulated by the demodulator by use of a parity signal;
a first expander which bit-expands video information among digital information error detected by the error detector corresponding to the first compression system; and
a second expander which bit-expands audio information among digital information error detected by the error detector corresponding to the second compression system.
2. An apparatus according to claim 1 , wherein the first compression system and the second compression system are different systems.
3. An apparatus according to claim 1 , wherein the demodulator affects QPSK demodulation.
4. 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.
5. An apparatus for recording digital information which is digital video information bit-compressed by a first compression system using discrete cosine transform plus digital audio information bit-compressed by a second compression system, and which has been error-detected by use of a first parity signal added to the digital information and received from a receiving apparatus, comprising:
an input terminal which inputs the digital information from the receiving apparatus;
a parity signal adder which adds a second parity signal to the inputted digital information which is different from the first parity signal;
a modulator which modulates the second parity signal added digital information added by the parity signal adder; and
a recorder which records the digital information modulated by the modulator on a recording media;
wherein the digital information received from the receiving apparatus is recorded to the recording media with no further expansion and/or compression processing.
6. An apparatus for recording digital information which is digital video information bit-compressed by a first compression system using discrete cosine transform plus a digital audio information bit-compressed by a second compression system, and which has been demodulated corresponding to a first modulation system and received from a receiving apparatus comprising:
an input terminal which inputs the digital information from the receiving apparatus;
a parity signal adder which adds a recording parity signal to the inputted digital information;
a modulator which modulates the recording parity signal added digital information added by the parity signal adder, by using a second modulation system which is different from the first modulation system; and
a recorder which records the digital information modulated by the modulator on a recording media;
wherein the digital information received from the receiving apparatus is recorded to the recording media with no further expansion and/or compression processing.
7. An apparatus according to claim 1 , wherein the first compression system uses a discrete cosine transform, the received digital information is phase-modulated, and the demodulator demodulates the digital information received by the receiver in accordance with the phase-modulation.
8. An apparatus for processing a transmitted digital signal, comprising:
a receiver which receives the transmitted digital signal, wherein the transmitted digital signal includes video signal bit-compressed by a first compression method, an audio signal bit-compressed by a second compression method, and a parity signal for error correction;
a demodulator which demodulates the digital signal received by the receiver;
an error corrector which corrects an error of the digital signal demodulated by the demodulator based on the parity signal;
a first expander which bit-expands the video signal of the digital signal corrected by the error corrector in accordance with the first compression method; and
a second expander which bit-expands the audio signal of the digital signal corrected by the error corrector in accordance with the second compression method.
9. The apparatus according to claim 8 , wherein the first compression method utilizes a discrete cosine transform.