Method of and apparatus for data recording, method of and apparatus for data reproduction, recording medium, and method of and apparatus for data transmission

Abstract

Disclosed are a method of and apparatus for data recording, a method of and apparatus for data reproduction, a recording medium, and a method of and apparatus for data transmission in which compression-coded moving picture signals can be continuously reproduced irrespective of the amount of information generated. When recording data obtained by compression-coding a moving picture signal of a fixed period of time on a recording medium, only writing to an FIFO buffer memory is effected and reading to the recording medium is inhibited for a fixed period of time from the output start of the data and, after the fixed period of time has elapsed, the writing of the compression-coded data to the FIFO buffer memory is continued and, at the same time, the data written to the FIFO buffer memory is read out at a data rate which is riot lower than the data rate for the writing to packetize the data, the data thus packetized being recorded on the recording medium.

What is claimed is:  
     
         1 . A data recording method in which a moving picture signal of a fixed period of time T is compression-coded and recorded on a recording medium, comprising the steps of: 
 writing the compression-coded data to a first buffer memory and inhibiting recording the same on the recording medium for a fixed period of time Tw from the input start of compression-coded data;    after the fixed period of time Tw has elapsed, continuing the writing of the compression-coded data to the first buffer memory and reading out the compression-coded data written to the first buffer memory at a data rate Rw which is not lower than the data rate Re of the writing to the first buffer memory;    packetizing the read compression-coded data of a fixed size; and,    recording the packetized data on the recording medium.    
     
     
         2 . A data recording method according to    claim 1   , wherein the fixed period of time Tw is set to be a value (Be/Re) which is not smaller than the value of the minimum requisite time for reading an amount of data corresponding to the total capacity (Be) of a second buffer memory, which is provided in an encoding section for encoding the moving picture signal into compression-coded data and outputting it, from this second buffer memory.  
     
     
         3 . A data recording method according to    claim 1   , wherein the data rate at which the compression-coded data is read from the first buffer memory after the fixed period of time Tw has elapsed is a data rate sufficient for making it possible for compression-coded data corresponding to the moving picture signal of the fixed period of time T and data corresponding to the total capacity Be of a second buffer memory, which is provided in an encoding section for encoding the moving picture signal into compression-coded data and outputting it, to be read within the fixed period of time T.  
     
     
         4 . A data recording method according to    claim 1   , wherein, when the first memory has become empty during the reading of compression-coded data from the first memory, meaningless stuffing data is added to thereby generate the packet data of a fixed size.  
     
     
         5 . A data recording apparatus comprising: 
 an encoding section for compression-coding a moving picture signal of a fixed period of time T and outputting it;    a first buffer memory to which compression-coded data is input from the encoding section and which, for a fixed period of time Tw from the input start of the compression-coded data, only allows the writing of the compression-coded data and inhibits reading and, after the fixed period of time Tw has elapsed, reads the compression-coded data that has been written at a data rate which is not lower than the data rate for the writing while continuing the writing of the compression-coded data; and    a packetizing section for packetizing the compression-coded data read from the first buffer memory and recording it on a recording medium always as packet data of a fixed size.    
     
     
         6 . A data recording apparatus according to    claim 5   , wherein the fixed period of time Tw is set to be a value which is not smaller than the value of the minimum requisite time for reading an amount of data corresponding to the total capacity Be of a second buffer memory, which is provided in the encoding section, from this second buffer memory.  
     
     
         7 . A data recording apparatus according to    claim 5   , wherein the data rate at which the compression-coded data is read from the first buffer memory after the fixed period of time Tw has elapsed is a data rate sufficient for making it possible for compression-coded data corresponding to the moving picture signal of the fixed period of time T and data corresponding to the total capacity of a second buffer memory, which is provided in the encoding section, within the fixed period of time T.  
     
     
         8 . A data recording apparatus according to    claim 5   , further comprising means for generating stuffing data, wherein, when the first memory has become empty during the reading of compression-coded data from the first memory, the packetizing section adds the stuffing data to generate the packet data  
     
     
         9 . A data reproducing method in which compression-coded data obtained by compression-coding a moving picture signal of a fixed period of time T is accumulated in a first buffer memory for a fixed period of time Tw from the input start and, after that, while the writing to the first buffer memory is being continued, data is read at a rate higher than the writing rate to packetize the data to thereby obtain packet data, which is recorded on a recording medium and reproduced therefrom, the reproducing method comprising the steps of: 
 reading out the packet data at a data rate not lower than the data rate at which the packet data was written to the recording medium;    writing the read out packet data to a second buffer memory;    reading out the data written to the second buffer memory at a data rate which is substantially the same as the data rate of writing the compression-coded data to the first buffer memory; and    decoding the data.    
     
     
         10 . A data reproducing apparatus comprising: 
 a data extracting section in which compression-coded data obtained by compression-coding a moving picture signal of a fixed period of time T is accumulated in a first buffer memory for a fixed period of time Tw from the output start and, after that, while the writing to the first buffer memory is being continued, data is read at a rate higher than the writing rate to packetize the data to thereby obtain packet data, which is recorded on a recording medium and read therefrom, the compression-coded data being extracted from this packet data;    a second buffer memory to which the compression-coded data is sequentially input and written from the data extracting section, wherein, after the writing, the compression-coded data is read out at a data rate which is lower than the rate at which the compression-coded data is read from the data extracting section and which is substantially the same as the data rate at which the compression coding is effected; and    a decoding section for decoding the compression-coded data read from the second buffer memory to obtain the moving picture signal.    
     
     
         11 . A recording medium on which compression-coded data obtained by compression-coding a moving picture signal of a fixed period of time T is recorded as packet data of a fixed size regardless of the amount of compression-coded data generated, 
 wherein said packet data is of the following two kinds:    first packet data consisting of header data and the compression-coded data; and    second packet data consisting of header data, the compression-coded data and dummy data.    
     
     
         12 . A data transmission method in which data obtained by compression-coding a moving picture signal of a fixed period of time T is transmitted through a transmission line, comprising the steps of: 
 writing the compression-coded data to a first buffer memory and inhibiting data output to the transmission line for a fixed period of time Tw from the input start of the compression-coded data;    after the fixed period of time Tw has elapsed, continuing the writing of the compression-coded data to the first buffer memory and reading out the compression-coded data that has been written to the first buffer memory at a data rate Rw which is not lower than the data writing rate;    packetizing the read compression-coded data of a fixed size; and    outputting the packetized data to the transmission line.    
     
     
         13 . A data transmission apparatus comprising: 
 an encoding section for compression-coding a moving picture signal of a fixed period of time T and outputting it;    a first buffer memory to which compression-coded data is input from the encoding section and which, for a fixed period of time Tw from the input start of the compression-coded data, only allows the writing of the compression-coded data and inhibits outputting and, after the fixed period of time Tw has elapsed, reads the compression-coded data that has been written at a data rate which is not lower than the data rate for the writing while continuing the writing of the compression-coded data; and    a packetizing section for packetizing the compression-coded data read from the first buffer memory and outputting it to a transmission line always as packet data of a fixed size.    
     
     
         14 . A data transmission method in which compression-coded data obtained by compression-coding a moving picture signal of a fixed period of time T is accumulated in a first buffer memory for a fixed period of time Tw from the input start and, after that, while the writing to the first buffer memory is being continued, data is read at a rate higher than the writing rate to packetize the data, which is received through a transmission line, the data transmission method comprising the steps of: 
 reading out the packet data at a data rate not lower than the data rate at which the packet data was output to the transmission line;    writing the read out packet data to a second buffer memory;    reading out the data written to the second buffer memory at a data rate which is substantially the same as the data rate of writing the compression-coded data to the first buffer memory; and    transmitting the data.    
     
     
         15 . A data transmission apparatus comprising: 
 a data extracting section in which compression-coded data obtained by compression-coding a moving picture signal of a fixed period of time T is accumulated in a first buffer memory for a fixed period of time Tw from the output start and, after that, while the writing to the first buffer memory is being continued, data is read at a rate higher than the writing rate to packetize the data to thereby obtain packet data, which is received through a transmission line, the compression-coded data corresponding to the moving picture signal being extracted from this packet data;    a second buffer memory to which the compression-coded data read from the data extracting section is sequentially input and written from the data extracting section, wherein, after the writing, the compression-coded data is read out at a data rate which is lower than the data rate at which the compression-coded data is read from the data extracting section and which is substantially the same as the data rate at which the compression coding is effected; and    a decoding section for decoding the compression-coded data read from the second buffer memory to obtain the moving picture signal.    
     
     
         16 . A data recording method in which a moving picture signal of a fixed period of time T is compression-coded and recorded on a recording medium, comprising the steps of: 
 packetizing compression-coded data output from an encoding section into packet data of a fixed size;    writing the packet data to a first buffer memory and inhibiting recording thereof on the recording medium for a fixed period of time Tw from the output start of the packet data;    after the fixed period of time Tw has elapsed, continuing writing of the packet data to the first buffer memory; and,    reading out the packet data that has been written to the first buffer memory at a data rate which is not lower than the data rate of the writing to the first buffer memory to record the data on the recording medium.    
     
     
         17 . A data recording method according to    claim 16   , wherein the fixed period of time Tw is set to be a value which is not smaller than the value of the minimum requisite time for reading an amount of data corresponding to the total capacity of a second buffer memory, which is provided in an encoding section for encoding the moving picture signal into compression-coded data and outputting it, from this second buffer memory.  
     
     
         18 . A data recording method according to    claim 16   , wherein the data rate at which the packet data is read from the first buffer memory after the fixed period of time Tw has elapsed is a data rate sufficient for making it possible for compression-coded data corresponding to the moving picture signal of the fixed period of time T and data corresponding to the total capacity of a second buffer memory, which is provided in an encoding section for encoding the moving picture signal into compression-coded data and outputting it, to be read within the fixed period of time T.  
     
     
         19 . A data recording method according to    claim 16   , wherein, when the first memory has become empty during the reading of the packet data from the first memory, a meaningless padding packet is generated and recorded on the recording medium.  
     
     
         20 . A data recording apparatus comprising: 
 an encoding section for compression-coding a moving picture signal of a fixed period of time T and outputting it;    a packetizing section to which compression-coded data is input from the encoding section and in which the compression-coded data is packetized; and    a first buffer memory to which packet data is input from the encoding section and which, for a fixed period of time Tw from the input start of the packet data, only allows the writing of the packet data and inhibits the reading thereof and, after the fixed period of time Tw has elapsed, reads the packet data that has been written at a data rate which is not lower than the data rate for the writing while continuing the writing of the packet data and writes it to a recording medium.    
     
     
         21 . A data recording apparatus according to claim  20 , wherein the fixed period of time Tw is set to be a value which is not smaller than the value of the minimum requisite time for reading an amount of data corresponding to the total capacity of a second buffer memory, which is provided in the encoding section, from this second buffer memory.  
     
     
         22 . A data recording apparatus according to    claim 20   , wherein the data rate at which the packet data is read from the first buffer memory after the fixed period of time Tw has elapsed is a data rate sufficient for making it possible for compression-coded data corresponding to the moving picture signal of the fixed period of time T and data corresponding to the total capacity of a second buffer memory, which is provided in the encoding section, within the fixed period of time T.  
     
     
         23 . A data recording apparatus according to    claim 20   , further comprising means for generating a meaningless padding packet, wherein, when the first memory has become empty during the reading of the packet data from the first memory, the padding packet is recorded on the recording medium.  
     
     
         24 . A data reproducing method in which packet data that is obtained by packetizing compression-coded data obtained by compression-coding a moving picture signal of a fixed period of time T is accumulated in a first buffer memory for a fixed period of time Tw from the output start and, after that, while the writing to the first buffer memory is being continued, the packet data is read at a rate higher than the writing rate and recorded on a recording medium and reproduced therefrom, the reproducing method comprising the steps of: 
 reading out the packet data at a data rate not lower than the data rate at which it was written to the recording medium;    writing the read out packet data to a second buffer memory;    reading out the packet data written to the second buffer memory at a data rate which is substantially the same as the data rate for the packetizing; and    decoding the packet data read out of the second buffer memory.    
     
     
         25 . A data reproducing apparatus comprising: 
 a data extracting section in which packet data that is obtained by packetizing compression-coded data obtained by compression-coding a moving picture signal of a fixed period of time T is accumulated in a first buffer memory for a fixed period of time Tw from the output start and, after that, while the writing to the first buffer memory is being continued, the packet data is read from a recording medium at a rate higher than the writing rate to extract the compression-coded data from the packet data;    a second buffer memory to which the packet data is sequentially input and written from the data extracting section, wherein, after the writing, the packet data is read out at a data rate which is lower than the rate at which the packet data is read from the data extracting section and which is substantially the same as the data rate at which the packetizing of the compression-coded data is effected; and    a decoding section for decoding the packet data read from the second buffer memory to obtain the moving picture signal.    
     
     
         26 . A recording medium on which compression-coded data obtained by compression-coding a moving picture signal of a fixed period of time T is recorded always as packet data of a fixed size regardless of the amount of compression-coded data generated, 
 wherein said packet data is of the following two kinds:    first packet data consisting of header data and the compression-coded data; and    second packet data consisting of header data and dummy data.    
     
     
         27 . A data transmission method in which data obtained by compression-coding a moving picture signal of a fixed period of time T is transmitted through a transmission line, comprising the steps of: 
 packetizing the compression-coded data output from the encoding section into packet data of a fixed size;    writing the packet data to a first buffer memory and inhibiting data output to the transmission line for a fixed period of time Tw from the output start of the packet data;    after the fixed period of time Tw has elapsed, continuing the writing of the packet data to the first buffer memory; and    reading out the packet data that has been written to the first buffer memory at a data rate which is not lower than the data writing rate to transmit the packet data to the transmission line.    
     
     
         28 . A data transmission apparatus comprising: 
 an encoding section for compression-coding a moving picture signal of a fixed period of time T and outputting it;    a packetizing section for packetizing the compression-coded data read from the first buffer memory and outputting it as packet data; and    a first buffer memory to which the packet data is input and which, for a fixed period of time Tw from the input start of the packet data, only allows the writing of the packet data and inhibits the outputting thereof and, after the fixed period of time Tw has elapsed, reads the packet data that has been written at a data rate which is not lower than the data rate for the writing while continuing the input of the packet data.    
     
     
         29 . A data transmission method in which packet data that is obtained by packetizing compression-coded data obtained by compression-coding a moving picture signal of a fixed period of time T is accumulated in a first buffer memory for a fixed period of time Tw from the output start and, after that, while the writing to the first buffer memory is being continued, the packet data is read at a rate higher than the writing rate and recorded on a recording medium and read therefrom, the data transmission method comprising the steps of: 
 reading out the packet data at a data rate not lower than the data rate at which it was written to the recording medium;    writing the read out packet data to a second buffer memory;    reading out the packet data written to the second buffer memory at a data rate which is substantially the same as the data rate for the packetizing; and    decoding the packet data read out of the second buffer memory.    
     
     
         30 . A data transmission apparatus comprising: 
 a data extracting section in which packet data that is obtained by packetizing compression-coded data obtained by compression-coding a moving picture signal of a fixed period of time T is accumulated in a first buffer memory for a fixed period of time Tw from the output start and, after that, while the writing to the first buffer memory is being continued, the packet data is read at a rate higher than the writing rate and received form a transmission line for data transmission, the compression-coded data corresponding to the moving picture signal being extracted from this packet data;    a second buffer memory to which the packet data read from the data extracting section is sequentially input and written, wherein, after the writing, the packet data is read out at a data rate which is lower than the data rate at which the compression-coded data is read from the data extracting section and which is substantially the same as the data rate for the packetizing of the data; and    a decoding section for decoding the packet data read from the second buffer memory to obtain the moving picture signal.