Video decoding apparatus and method

Abstract

A video decoding apparatus and method capable of performing high-speed reproduction of image data subjected to coding with a prescribed coding scheme for adaptively performing field-structured or frame-structured coding, with a simple configuration. In a high-speed reproduction mode, a decoding process is applied to only coded image data of intra-frame coded pictures subjected to the frame-structured coding or of one field in the intra-frame coded pictures and coded image data of intra-field coded pictures subjected to the field-structured coding.

1 - 8 . (canceled) 
   
   
       9 . A video decoding apparatus for performing a decoding process on coded image data comprising image data subjected to a prescribed coding scheme for adaptively performing frame-structured coding, the video decoding apparatus comprising:
 decoding means for decoding the coded image data;   control means for controlling, in a high-speed reproduction mode, the decoding means to perform the decoding process only on intra-frame coded pictures of the coded image data subjected to the frame-structured coding to obtain decoded image data having a first field and a second field; and   field/frame conversion means for deleting the second field of the decoded image data and copying the first field of the decoded image data into the second field of the decoded image data to create image data of a decoded picture.   
   
   
       10 . The video decoding apparatus according to  claim 9 , further comprising filtering means for performing a prescribed filtering process on the decoded image data, wherein the control means controls, in the high-speed reproduction mode, the filtering means so as not to perform the filtering process on the decoded image data. 
   
   
       11 . The video decoding apparatus according to  claim 10 , wherein the filtering process is a deblock filtering process to reduce block noise. 
   
   
       12 . A video decoding method for performing a decoding process on coded image data comprising image data subjected to a prescribed coding scheme for adaptively performing frame-structured coding, the video decoding method comprising:
 performing the decoding process, in a high-speed reproduction mode, only on intra-frame coded pictures of the coded image data subjected to the frame-structured coding to obtain decoded image data having a first field and a second field;   deleting the second field of the decoded image data; and   copying the first field into the second field to create image data of a decoded picture.   
   
   
       13 . The video decoding method according to  claim 12 , further comprising:
 performing the decoding process on the coded image data in a normal-speed reproduction mode to obtain normally decoded image data; and   performing a prescribed filtering process on the normally decoded image data, wherein the filtering process is not performed on the decoded image data obtained in the high-speed reproduction mode.   
   
   
       14 . The video decoding method according to  claim 13 , wherein the filtering process is a deblock filtering process to reduce block noise. 
   
   
       15 . A video decoding apparatus for decoding coded image data, the apparatus comprising:
 a decoding unit for decoding the coded image data subjected to frame-structured coding to create decoded image data without performing a deblock filtering process, the decoded image data including a first field and a second field; and   a field/frame conversion unit for deleting the second field of the decoded image data and copying the first field into the second field to create converted decoded image data.   
   
   
       16 . The video decoding apparatus of  claim 15 , further comprising:
 a digital/analog converter for converting the converted decoded image data into a reproduction video signal.   
   
   
       17 . The video decoding apparatus of  claim 16 , wherein the decoding unit comprises:
 an intra prediction unit for creating intra-predicted image data; and   an adder for adding the intra-predicted image data with difference image data to obtain the decoded image data.   
   
   
       18 . The video decoding apparatus of  claim 17 , wherein the decoding unit comprises:
 a motion prediction/compensation unit for creating reference image data; and   an adder for adding the reference image data with difference image data to obtain the decoded image data.   
   
   
       19 . A video decoding apparatus for performing a decoding process on coded image data comprising image data subjected to a prescribed coding scheme for adaptively performing field-structured coding, the video decoding apparatus comprising:
 decoding means for decoding the coded image data;   control means for controlling, in a high-speed reproduction mode, the decoding means to perform the decoding process only on intra-field coded pictures of the coded image data subjected to the field-structured coding to obtain decoded image data; and   field/frame conversion means for copying a first field of the decoded image data into a second field of the decoded image data to create image data of a decoded picture.   
   
   
       20 . The video decoding apparatus according to  claim 19 , further comprising filtering means for performing a prescribed filtering process on decoded image data obtained by performing the decoding process on the coded image data, wherein the control means controls, in the high-speed reproduction mode, the filtering means so as not to perform the filtering process on the decoded image data. 
   
   
       21 . The video decoding apparatus according to  claim 20 , wherein the filtering process is a deblock filtering process to reduce block noise. 
   
   
       22 . A video decoding method for performing a decoding process on coded image data comprising image data subjected to a prescribed coding scheme for adaptively performing field-structured coding, the video decoding method comprising:
 performing the decoding process, in a high-speed reproduction mode, only on intra-field coded pictures of the coded image data subjected to the field structured coding to obtain decoded image data; and   copying a first field of the decoded image data into a second field of the decoded image data to create image data of a decoded picture.   
   
   
       23 . The video decoding method according to  claim 22 , further comprising:
 performing the decoding process on the coded image data in a normal-speed reproduction mode to obtain normally decoded image data; and   performing a prescribed filtering process on the normally decoded image data, wherein the filtering process is not performed on the decoded image data obtained in the high-speed reproduction mode.   
   
   
       24 . The video decoding method according to  claim 23 , wherein the filtering process is a deblock filtering process to reduce block noise. 
   
   
       25 . A video decoding apparatus for decoding coded image data, the apparatus comprising:
 a decoding unit for decoding the coded image data subjected to field-structured coding to create decoded image data without performing a deblock filtering process; and   a field/frame conversion unit for copying a first field of the decoded image data into a second field of the decoded image data to create converted decoded image data.   
   
   
       26 . The video decoding apparatus of  claim 25 , further comprising:
 a digital/analog converter for converting the converted decoded image data into a reproduction video signal.   
   
   
       27 . The video decoding apparatus of  claim 26 , wherein the decoding unit comprises:
 an intra prediction unit for creating intra-predicted image data; and   an adder for adding the intra-predicted image data with difference image data to obtain the decoded image data.   
   
   
       28 . The video decoding apparatus of  claim 27 , wherein the decoding unit comprises:
 a motion prediction/compensation unit for creating reference image data; and   an adder for adding the reference image data with difference image data to obtain the decoded image data.