Input-output circuit, recording apparatus and reproduction apparatus for digital video signal
A video signal input-output circuit and a recording-reproduction apparatus in which a digitally compressed video signal input in packet form can be recorded and reproduced efficiently and in stable fashion. In this apparatus, a clock reference is detected from a packet signal containing the clock reference and a digitally compressed video signal, a time stamp for a packet is generated using a clock signal in phase with the clock reference and added to the particular packet, and the packet signals with the time stamp added thereto are recorded closely to each other in a data storage element such as a magnetic recording medium. At playback, the packet interval is output by being restored to the original length on the basis of the time stamp added to the packet in store.
1. A digital video signal recording method for recording a digitally compressed video signal on a recording medium having a recording area composed of a plurality of blocks, the digitally compressed video signal being an intermittent input signal in the form of fixed length packets, the method comprising the steps of:
inputting a digitally compressed video signal, the digitally compressed video signal being an intermittent input signal in the form of fixed length packets;
generating a reference clock of a predetermined frequency;
adding a time stamp to each packet based on the reference clock, the time stamp indicating an input timing of the packets; and
recording a number m of the packets in a number n of the blocks on the recording medium, n and m being predetermined integers (n<m).
2. An apparatus for recording a digitally compressed video signal on a recording medium having a recording area composed of a plurality of blocks, the digitally compressed video signal being an intermittent input signal in the form of fixed length packets, the apparatus comprising:
an input circuit which inputs a digitally compressed video signal, the digitally compressed video signal being an intermittent input signal in the form of fixed length packets,
a generation circuit which generates a reference clock of a predetermined frequency;
an adding circuit which adds a time stamp to the packets based on the reference clock, the time stamp indicating an input timing of the packets; and
a recording circuit which records a number m of the packets in a number n of the blocks on the recording medium, n and m being predetermined integers (n<m).
3. A method for reproducing a digitally compressed video signal recorded on a recording medium having a recording area composed of a plurality of blocks, the digitally compressed video signal being an intermittent input signal in the form of fixed length packets, the method comprising the steps of:
reproducing the packets recorded on the recording medium, the packets being recorded on the recording medium, the packets including a time stamp indicating an output timing of the packets, a number m of the packets being included in a number n of the blocks on the recording medium, n and m being predetermined integers (n<m);
generating a clock signal using a local oscillator;
adjusting the output timing of the reproduced packets based on the time stamp and the clock signal from the local oscillator so as to restore original time intervals of the intermittent input signal; and
outputting the adjusted packets.
4. An apparatus for reproducing a digitally compressed video signal recorded on a recording medium having a recording area composed of a plurality of blocks, the digitally compressed video signal being an intermittent input signal in the form of fixed length packets, the apparatus comprising:
a reproducing circuit which reproduces the packets recorded on the recording medium, the packets being recorded on the recording medium, the packets including a time stamp indicating an output timing of the packets, a number m of the packets being included in a number n of the blocks on the recording medium, n and m being predetermined integers (n<m);
a local oscillator which generates a clock signal;
an adjusting circuit which adjusts the output timing of the reproduced packets based on the time stamp and the clock signal from the local oscillator so as to restore original time intervals of the intermittent input signal; and
an output circuit which outputs the adjusted packets.