Recording apparatus, recording method, reproducing apparatus, and reproducing method

Abstract

MPEG streams of different chroma formats are recorded and reproduced without need to recognize their formats. In an MPEG stream, a header is followed by DCT blocks. Time slots are generated in such a manner that when the chroma format detected from the header is 4:2:2, in all periods of DCT blocks, a process is performed and that when the chroma format detected from the header is 4:2:0, a process is not performed in periods for DCT blocks Cb 2 and Cr 2 that are not present in the chroma format 4:2:2. The read order of a stream is changed in a memory so as to improve an error resistance. DCT coefficients are rearranged in the order of DC components and AC components from the lowest order component to the highest order component over all DCT blocks. After the stream has been rearranged, time slots are generated in such as manner that when the chroma format is 4:2:0, the process is stopped in the periods for Cb 2 and Cr 2 . With the time slots, corresponding to the chroma format, the process is controlled so that the chroma formats 4:2:2 and 4:2:0 can be processed in common.

1 - 10 . (canceled)  
     
     
         11 . An encoding apparatus for encoding a digital video signal of which a screen is divided into first blocks in a predetermined manner, a luminance signal and two color difference signals of each first block being divided into second blocks corresponding to a chroma format based on the ratio of sampling frequencies of the luminance signal and the two color difference signals, in the digital video signal, the luminance signal and the two color difference signals having been compression-encoded for each second block, the encoding apparatus, comprising: 
 detecting means for detecting a first chroma format that represents the ratio of sampling frequencies of the luminance signal and the two color difference signals of an input digital video signal; and    controlling means for stopping a process for the input digital video signal in a period corresponding to the difference between a predetermined information amount represented by a second chroma format and the information amount represented by the first chroma format when the information amount represented by the first chroma format is smaller than the information amount of the second chroma format corresponding to the first chroma format detected by said detecting means.    
     
     
         12 . The encoding apparatus as set forth in  claim 11 , wherein the input digital video signal is MPEG encoded data.  
     
     
         13 . The encoding apparatus as set forth in  claim 11 , wherein in the first chroma format, the ratio of sampling frequencies of the luminance signal and the two color difference signals is 4:2:0, and in the second chroma format, the ratio of sampling frequencies of the luminance signal and the two color difference signals is 4:2:2.  
     
     
         14 . The encoding apparatus as set forth in  claim 11 , wherein in the second chroma format, the ratio of sampling frequencies of the luminance signal and the two color difference signals is 4:4:4.  
     
     
         15 . An encoding method for encoding a digital video signal of which a screen is divided into first blocks in a predetermined manner, a luminance signal and two color difference signals of each first block being divided into second blocks corresponding to a chroma format based on the ratio of sampling frequencies of the luminance signal and the two color difference signals, in the digital video signal, the luminance signal and the two color difference signals having been compression-encoded for each second block, the encoding method, comprising the steps of: 
 detecting a first chroma format that represents the ratio of sampling frequencies of the luminance signal and the two color difference signals of an input digital video signal; and    stopping a process for the input digital video signal in a period corresponding to the difference between a predetermined information amount represented by a second chroma format and the information amount represented by the first chroma format when the information amount represented by the first chroma format is smaller than the information amount of the second chroma format corresponding to the first chroma format detected at the detecting step.    
     
     
         16 . A decoding apparatus for decoding a digital video signal of which a screen is divided into first blocks in a predetermined manner, a luminance signal and two color difference signals of each first block being divided into second blocks corresponding to a chroma format based on the ratio of sampling frequencies of the luminance signal and the two color difference signals, in the digital video signal, the luminance signal and the two color difference signals having been compression-encoded for each second block, the decoding apparatus, comprising: 
 decoding means for decoding the digital video signal;    detecting means for detecting a first chroma format that represents the ratio of sampling frequencies of the luminance signal and the two color difference signals of the digital video signal decoded by said decoding means; and    controlling means for stopping a process for the decoded digital video signal in a period corresponding to the difference between a predetermined information amount represented by a second chroma format and the information amount represented by the first chroma format when the information amount represented by the first chroma format is smaller than the information amount of the second chroma format corresponding to the first chroma format detected by said detecting means.    
     
     
         17 . The decoding apparatus as set forth in  claim 16 , wherein the input digital video signal is MPEG encoded data.  
     
     
         18 . The decoding apparatus as set forth in  claim 16 , wherein in the first chroma format, the ratio of sampling frequencies of the luminance signal and the two color difference signals is 4:2:0, and in the second chroma format, the ratio of sampling frequencies of the luminance signal and the two color difference signals is 4:2:2.  
     
     
         19 . The decoding apparatus as set forth in  claim 16 , wherein in the second chroma format, the ratio of sampling frequencies of the luminance signal and the two color difference signals is 4:4:4.  
     
     
         20 . A decoding method for decoding a digital video signal of which a screen is divided into first blocks in a predetermined manner, a luminance signal and two color difference signals of each first block being divided into second blocks corresponding to a chroma format based on the ratio of sampling frequencies of the luminance signal and the two color difference signals, in the digital video signal, the luminance signal and the two color difference signals having been compression-encoded for each second block, the decoding method, comprising the steps of: 
 decoding the digital video signal;    detecting a first chroma format that represents the ratio of sampling frequencies of the luminance signal and the two color difference signals of the digital video signal decoded at the decoding step; and    stopping a process for the decoded digital video signal in a period corresponding to the difference between a predetermined information amount represented by a second chroma format and the information amount represented by the first chroma format when the information amount represented by the first chroma format is smaller than the information amount of the second chroma format corresponding to the first chroma format detected at the detecting step.    
     
     
         21 . An encoding apparatus for encoding a digital video signal of which a screen is divided into first blocks in a predetermined manner, a luminance signal and two color difference signals of each first block being divided into second blocks corresponding to a chroma format based on the ratio of sampling frequencies of the luminance signal and the two color difference signals, in the digital video signal, the luminance signal and the two color difference signals having been compression-encoded for each second block, the encoding apparatus, comprising: 
 a detector adapted to detect a first chroma format that represents the ratio of sampling frequencies of the luminance signal and the two color difference signals of an input digital video signal; and    a controller adapted to stop a process for the input digital video signal in a period corresponding to the difference between a predetermined information amount represented by a second chroma format and the information amount represented by the first chroma format when the information amount represented by the first chroma format is smaller than the information amount of the second chroma format corresponding to the first chroma format detected by the detector.    
     
     
         22 . A decoding apparatus for decoding a digital video signal of which a screen is divided into first blocks in a predetermined manner, a luminance signal and two color difference signals of each first block being divided into second blocks corresponding to a chroma format based on the ratio of sampling frequencies of the luminance signal and the two color difference signals, in the digital video signal, the luminance signal and the two color difference signals having been compression-encoded for each second block, the decoding apparatus, comprising: 
 a decoder adapted to decode the digital video signal;    a detector adapted to detect a first chroma format that represents the ratio of sampling frequencies of the luminance signal and the two color difference signals of the digital video signal decoded by the decoder; and    a controller adapted to stop a process for the decoded digital video signal in a period corresponding to the difference between a predetermined information amount represented by a second chroma format and the information amount represented by the first chroma format when the information amount represented by the first chroma format is smaller than the information amount of the second chroma format corresponding to the first chroma format detected by the detector.