Video encoding apparatus, video decoding apparatus, video encoding method, and video decoding method

Abstract

A video encoding apparatus appends decoding delay and display delay correction information to encoded video data in order to ensure that even when one or more pictures that are later in encoding order than a starting encoded picture in a video data stream to be spliced to a trailing end of another encoded video data stream have been discarded from among pictures contained in the video data stream, the starting encoded picture and its subsequent pictures can be continuously decoded and displayed by a video decoding apparatus. The correction information is calculated based on a decoding interval between each discarded picture and a picture that immediately precedes the discarded picture. The video decoding apparatus corrects the decoding delay and display delay of the starting encoded picture and its subsequent pictures by using the calculated correction information.

What is claimed is: 
     
         1 . A video encoding apparatus for generating spliced encoded video data by splicing together first video data and second video data both encoded using inter-frame predictive coding, comprising:
 a splicing point identification information processing unit which obtains decoding delay and display delay correction information for ensuring that even when one or more pictures that are later in encoding order than a starting encoded picture in the second video data to be spliced to a trailing end of the first encoded video data have been discarded from among pictures contained in the second video data, the starting encoded picture and subsequent pictures contained in the second encoded video data can be continuously decoded and displayed by a video decoding apparatus, and which appends the correction information to the spliced video data; and   a data splicing unit which discards from the spliced video data any picture that is later in encoding order than the starting encoded picture and that is not guaranteed to be decoded correctly if decoding is started from the starting encoded picture, and wherein   the correction information is calculated based on a decoding interval between each discarded picture and a picture that immediately precedes the discarded picture in decoding order.   
     
     
         2 . The video encoding apparatus according to  claim 1 , wherein the correction information is obtained for the starting encoded picture as well as for any picture that is later in decode time but earlier in display time than the starting encoded picture, and the correction information carries a value corresponding to the sum of decoding intervals each provided between each picture that is later in decoding order in the spliced video data than the picture for which the correction information is obtained, and that has been discarded from the second video data, and the picture that immediately precedes the discarded picture in decoding order. 
     
     
         3 . A video decoding apparatus for decoding video data encoded by inter-frame predictive coding, comprising:
 a picture decoding/display time determining unit which uses information indicating that the encoded video data has been generated by splicing second encoded video data to a trailing end of first encoded video data and information indicating that one or more encoded pictures that are later in encoding order than a starting encoded picture in the second encoded video data spliced downstream of a splicing point at which the first encoded video data and the second encoded video data are spliced have been discarded to correct, based on correction information, a decoding delay for a picture that follows the starting encoded picture, and to correct, based on the correction information, display delays for the starting encoded picture and the picture that follows the starting encoded picture, and wherein   the correction information carries a value calculated based on a decoding interval between each picture that is later in decoding order than the starting encoded picture, and that has been discarded from the second encoded video data, and a picture that immediately precedes the discarded picture in decoding order.   
     
     
         4 . The video decoding apparatus according to  claim 3 , wherein the correction information is obtained for the starting encoded picture as well as for a first encoded picture that is later in decode time but earlier in display time than the starting encoded picture, and the correction information carries a value corresponding to the sum of decoding intervals each provided between each picture that is later in decoding order in the spliced video data than the picture for which the correction information is obtained, and that has been discarded from the second video data, and the picture that immediately precedes the discarded picture in decoding order. 
     
     
         5 . The video decoding apparatus according to  claim 4 , wherein the picture decoding/display time determining unit corrects the display delay of the starting encoded picture by subtracting the value of the correction information for the starting encoded picture from the value of the display delay that has been set for the starting encoded picture before the second video data is spliced to the first video data, and corrects the display delay of the first encoded picture by subtracting the value of the correction information for the first encoded picture from the value of the display delay that has been set for the first encoded picture before the second video data is spliced to the first video data. 
     
     
         6 . The video decoding apparatus according to  claim 5 , wherein the picture decoding/display time determining unit corrects the decoding delay of the first encoded picture by subtracting a difference between the value of the correction information for the starting encoded picture and the value of the correction information for the first encoded picture from the value of the decoding delay that has been set for the first encoded picture before the second video data is spliced to the first video data, and
 for a second encoded picture that follows the first encoded picture and is earlier in decoding order than a picture encoded subsequently to the starting encoded picture without referring to any other pictures, and that refers only to a picture occurring later than the starting picture, the picture decoding/display time determining unit corrects the decoding delay of the second encoded picture by subtracting the value of the correction information for the starting encoded picture from the value of the decoding delay for the second encoded picture that has been set before the second video data is spliced to the first video data.   
     
     
         7 . A video encoding method for generating spliced encoded video data by splicing together first video data and second video data both encoded using inter-frame predictive coding, comprising:
 obtaining decoding delay and display delay correction information for ensuring that even when one or more pictures that are later in encoding order than a starting encoded picture in the second video data to be spliced to a trailing end of the first encoded video data have been discarded from among pictures contained in the second video data, the starting encoded picture and subsequent pictures contained in the second encoded video data can be continuously decoded and displayed by a video decoding apparatus, and appending the correction information to the spliced video data; and   discarding from the spliced video data any picture that is later in encoding order than the starting encoded picture and that is not guaranteed to be decoded correctly if decoding is started from the starting encoded picture, and wherein   the correction information is calculated based on a decoding interval between each discarded picture and a picture that immediately precedes the discarded picture in decoding order.   
     
     
         8 . The video encoding method according to  claim 7 , wherein the correction information is obtained for the starting encoded picture as well as for any picture that is later in decode time but earlier in display time than the starting encoded picture, and the correction information carries a value corresponding to the sum of decoding intervals each provided between each picture that is later in decoding order in the spliced video data than the picture for which the correction information is obtained, and that has been discarded from the second video data, and the picture that immediately precedes the discarded picture in decoding order. 
     
     
         9 . A video decoding method for decoding video data encoded by inter-frame predictive coding, comprising:
 using information indicating that the encoded video data has been generated by splicing second encoded video data to a trailing end of first encoded video data and information indicating that one or more encoded pictures that are later in encoding order than a starting encoded picture in the second encoded video data spliced downstream of a splicing point at which the first encoded video data and the second encoded video data are spliced have been discarded, to correct, based on correction information, a decoding delay for a picture that follows the starting encoded picture, to correct, based on the correction information, display delays for the starting encoded picture and the picture that follows the starting encoded picture, and wherein   the correction information carries a value calculated based on a decoding interval between each picture that is later in decoding order than the starting encoded picture, and that has been discarded from the second encoded video data, and a picture that immediately precedes the discarded picture in decoding order.   
     
     
         10 . The video decoding method according to  claim 9 , wherein the correction information is obtained for the starting encoded picture as well as for a first encoded picture that is later in decode time but earlier in display time than the starting encoded picture, and the correction information carries a value corresponding to the sum of decoding intervals each provided between each picture that is later in decoding order in the spliced video data than the picture for which the correction information is obtained, and that has been discarded from the second video data, and the picture that immediately precedes the discarded picture in decoding order. 
     
     
         11 . The video decoding method according to  claim 10 , wherein the correcting the display delays corrects the display delay of the starting encoded picture by subtracting the value of the correction information for the starting encoded picture from the value of the display delay that has been set for the starting encoded picture before the second video data is spliced to the first video data, and corrects the display delay of the first encoded picture by subtracting the value of the correction information for the first encoded picture from the value of the display delay that has been set for the first encoded picture before the second video data is spliced to the first video data. 
     
     
         12 . The video decoding method according to  claim 11 , wherein the correcting the decoding delay corrects the decoding delay of the first encoded picture by subtracting a difference between the value of the correction information for the starting encoded picture and the value of the correction information for the first encoded picture from the value of the decoding delay that has been set for the first encoded picture before the second video data is spliced to the first video data, and
 for a second encoded picture that follows the first encoded picture and is earlier in decoding order than a picture encoded subsequently to the starting encoded picture without referring to any other pictures, and that refers only to a picture occurring later than the starting picture, the correcting the decoding delay corrects the decoding delay of the second encoded picture by subtracting the value of the correction information for the starting encoded picture from the value of the decoding delay for the second encoded picture that has been set before the second video data is spliced to the first video data.