Method and apparatus for receiving a digital signal and apparatus for recording and reproducing the digital signal
A method and apparatus is provided for receiving and/or reproducing a digital signal, capable of efficiently recording a compressed, packeted digital signal and inhibiting a copy thereof. An input packet signal is added with a time stamp indicating a relative time of an arrival of the packet, and the packet signals of digital information with the added time stamps are recorded at reduced intervals therebetween. In reproducing, a packet interval adjusting circuit restores the original packet intervals in accordance with the time stamps, and then a time stamp change circuit changes at least one bit of the time stamp and thereafter outputs the digital information.
1. A digital signal reproducing apparatus for reproducing a compressed digital signal from a recording medium, comprising:
a reproducing unit which reproduces a digitally packetized signal including a digital compressed audio signal, video signal, and clock reference signal from the recording medium, the digitally packetized signal being in a form of fixed length packets, each fixed length packet being formed by adding a time stamp indicating an output timing of the fixed length packet;
a counter which counts a value by a reference clock; and
an output unit which deletes the time stamp from each fixed length packet reproduced from the recording medium, and outputs the fixed length packets including the digital compressed audio signal, video signal, and clock reference signal to a decoder for decompressing the digital compressed audio signal and video signal in accordance with the time stamp added to each fixed length packet based on the value counted by the counter.
2. A digital signal reproducing method for reproducing a compressed digital signal from a recording medium, comprising:
reproducing a digitally packetized signal including a digital compressed audio signal, video signal, and clock reference signal from the recording medium, the digitally packetized signal being in a form of fixed length packets, each fixed length packet being form by adding a time stamp indicating an output timing of the fixed length packet;
counting a value by a reference clock;
deleting the time stamp from each fixed length packet reproduced from the recording medium; and
outputting the fixed length packet including the digital compressed audio signal, video signal, and clock reference signal to a decoder for decompressing the digital compressed audio signal and video signal in accordance with the time stamp added to each fixed length packet based on the value counted by the reference clock.