Video decoding device and video decoding method

Abstract

A video decoding device, in the case where a video of the progressive format is inputted, processes a frame as a picture, in the case where a video of the interlace format is inputted, processes a field as a picture. A video decoding device performs display control corresponding to a format of the both video by analyzing display control information in display control information analyzer. The display control information includes sequence unit display control information which is commonly used in a display process of all pictures that belong to a sequence to be decoded and picture unit display control information which is individually used in a display process of a picture to be decoded. A second code string analyzer acquires each of the sequence unit display control information and the picture unit display control information from an extended information area in units of pictures.

What is claimed is: 
     
         1 . A video decoding device for decoding a code string in units of pictures, the code string being acquired by encoding video signals in an interlace video format or a progressive video format in units of pictures, comprising:
 a second code string analyzer that analyzes the code string to acquire an extended information area code string and a first code string;   an extended information area decoder that acquires display control information to be used in displaying a decoded picture, from the extended information area code string;   a picture data decoder that decodes the first code string to acquire the picture by using common syntax analyzing method and a common signal processing method, which are not dependent on the video formats; and   an output picture setter that, in the case where the display control information indicates the progressive format, sets the acquired picture as a frame and outputs the frame one by one in a display order, and in the case where the display control information indicates the interlace format, sets the acquired picture as a field and outputs a pair of top field and bottom field in a display order when the pair of top field and bottom field are acquired, wherein   the display control information includes sequence unit display control information and picture unit display control information, the sequence unit display control information being commonly used in a display process of all pictures that belong to a sequence to be decoded and the picture unit display control information being individually used in a display process of a picture to be decoded, and   the extended information area decoder acquires each of the sequence unit display control information and the picture unit display control information from an extended information area in units of pictures.   
     
     
         2 . The video decoding device according to  claim 1 , wherein each extended information area of each picture that belongs to the same sequence stores the sequence unit display control information of the same value. 
     
     
         3 . The video decoding device according to  claim 1 , wherein the extended information area decoder acquires the sequence unit display control information that includes a first identifier specifying whether the video signals to be decoded are in the progressive format or the interlace format, and
 the output picture setter changes the output method of the picture based on the acquired first identifier.   
     
     
         4 . The video decoding device according to  claim 1 , wherein in the case where the video signals to be decoded are in the interlace format, the extended information area decoder acquires the sequence unit display control information that includes a second identifier specifying whether two fields that belong to the same frame are always continual with each other in a decoding order in the sequence, and
 the output picture setter changes the output method of the picture based on the acquired second identifier.   
     
     
         5 . The video decoding device according to  claim 1 , wherein in the case where the video signals to be decoded are in the interlace format, the extended information area decoder acquires the sequence unit display control information that includes information indicating a maximum value of an interval between a first field and a second field that belong to the same frame in the decoding order in the sequence, and
 the output picture setter changes the output method of the picture based on the acquired information indicating the maximum value.   
     
     
         6 . The video decoding device according to  claim 1 , wherein the extended information area decoder acquires the picture unit display control information that includes a third identifier specifying that the picture to be decoded is (1) to be displayed as a frame that belongs to the progressive video signals, (2) to be displayed as a top field that belongs to the interlace video signals, (3) to be displayed as a bottom field that belongs to the interlace video signals, or (4) to be displayed in another display format in the display process of the picture to be decoded, and
 the output picture setter changes the output method of the picture based on the acquired third identifier.   
     
     
         7 . The video decoding device according to  claim 1 , wherein only in the case where the video signals to be decoded are in the interlace format, the extended information area decoder acquires the picture unit display control information that includes a third identifier specifying that the picture to be decoded is (1) to be displayed as a top field that belongs to the interlace video signals or (2) to be displayed as a bottom field that belongs to the interlace video signals in the display process of the picture to be decoded, and
 the output picture setter changes the output method of the picture based on the acquired third identifier.   
     
     
         8 . The video decoding device according to  claim 1 , wherein, in the case where the picture to be decoded is to be displayed as a top field or a bottom field that belongs to the interlace video signals, the extended information area decoder acquires the picture unit display control information that includes specification information specifying a picture that is paired with the picture to be decoded and belongs to the same frame as that of the picture to be decoded, and
 the output picture setter outputs the picture to be decoded by setting the picture to be decoded as paired with the picture specified in the specification information.   
     
     
         9 . The video decoding device according to  claim 8 , wherein the extended information area decoder acquires, as the specification information, display order information that is assigned to the picture that is paired with the picture to be decoded and belongs to the same frame as that of the picture to be decoded. 
     
     
         10 . The video decoding device according to  claim 8 , wherein the extended information area decoder acquires, as the specification information, a difference value between display order information that is assigned to the picture to be decoded and display order information that is assigned to the picture that is paired with the picture to be decoded and belongs to the same frame as that of the picture to be decoded. 
     
     
         11 . A video decoding method for decoding a code string in units of pictures, the code string being acquired by encoding video signals in an interlace video format or a progressive video format in units of pictures, comprising:
 analyzing the code string to acquire an extended information area code string and a first code string;   acquiring display control information to be used in displaying a decoded picture, from the extended information area code string;   decoding the first code string to acquire the picture by using common syntax analyzing method and a common signal processing method, which are not dependent on the video formats; and   in the case where the display control information indicates the progressive format, sets the acquired picture as a frame and outputs the frame one by one in a display order, and in the case where the display control information indicates the interlace format, sets the acquired picture as a field and outputs a pair of top field and bottom field in a display order when the pair of top field and bottom field are acquired, wherein   the display control information includes sequence unit display control information and picture unit display control information, the sequence unit display control information being commonly used in a display process of all pictures that belong to a sequence to be decoded and the picture unit display control information being individually used in a display process of a picture to be decoded, and   each of the sequence unit display control information and the picture unit display control information is acquired from an extended information area in units of pictures.