Image processing device, image processing method, information processing device, and information processing method

1. An image processing device comprising:

a holder configured to hold therein hold information for a reference picture, necessary for decoding of an access unit, as a processing subject when decoding an input stream composed of access units, each access unit including a header;

an analyzer configured to analyze the entire input stream when input, prior to the input stream being decoded, to detect the header for each of the access units; and

a generator configured to,

(a) if the header indicating a change of a deletion order of pictures is detected by the analyzer, delete hold information for a picture from the holder in the deletion order indicated by the header and generate hold information indicating the reference picture to be held by the holder, and

(b) if a new hold information for a new reference picture needs to be included in a predetermined number of hold information for pictures held by the holder, the generator generates the hold information for the access unit in accordance with a first rule that hold information for pictures are deleted in decreasing order of a time period of being held in the holder.

2. The image processing device according to claim 1 , wherein

the header include a first header including information relating to coding of whole of the stream, a second header including information relating to coding of whole of the picture, and a third header including information indicating the change of the deletion order of the pictures.

3. The image processing device according to claim 2 , wherein

if the third header is detected by the analyzer, the generator creates the hold information in accordance with a second rule that pictures are deleted in deletion order specified by the third header.

4. The image processing device according to claim 1 , wherein

if the holder holds the new reference picture at a stage of decoding of a predetermined picture, the generator deletes the pictures in decreasing order of a time period of being held in the holder and generates the hold information in decoding order.

5. The image processing device according to claim 1 , further comprising

a decoding unit configured to decode the stream by controlling the picture to be held by the holder based on the hold information generated by the generator.

6. The image processing device according to claim 1 , wherein

the generator further creates information indicating output order of the pictures in the stream by using the header.

7. The image processing device according to claim 1 , further comprising

a storing unit configured to store the header analyzed by the analyzer and the hold information generated by the generator.

8. The image processing device according to claim 1 , wherein

the access unit includes actual data of a coded picture and including a header that allows specifying whether the reference picture is necessary for decoding of the picture and allows specifying of the reference picture if the reference picture is needed.

9. An image processing method of an image processing device including a holder that holds therein hold information for a reference picture, necessary for decoding of an access unit, as a processing subject when decoding an input stream composed of access units, each access unit including a header, the method comprising the steps of:

analyzing the entire input stream when input, prior to the input stream being decoded, to detect the header for each of the access units; and

(a) if the header indicating a change of a deletion order of pictures is detected by processing of the step of analyzing the input stream, deleting hold information for a picture from the holder in the deletion order indicated by the header and generating hold information indicating the reference picture to be held by the holder, and

(b) if a new hold information for a new reference picture needs to be included in a predetermined number of hold information for pictures held by the holder, generating the hold information for the access unit in accordance with a first rule that hold information for pictures are deleted in decreasing order of a time period of being held in the holder.

10. An information processing device comprising:

a holder configured to hold N hold information for pictures (N is an integer equal to or larger than one) including hold information for a reference picture, necessary for decoding of an access unit, as a processing subject when decoding of stream data composed of a plurality of access units in units of the access unit, the access unit including actual data of a coded picture and including a header that allows specifying whether a reference picture is necessary for decoding of the picture and allows specifying of the reference picture if the reference picture is needed;

an analyzer configured to analyze the entire stream data when input, prior to the stream data being decoded, to detect the header for each of the access units; and

a creator configured to create, prior to decoding the stream data, a list of hold information indicating the N hold information for pictures to be held by the holder at a stage of decoding for each of the access units included in the stream data, the list created prior to decoding the stream data by using the header detected by the analyzer in units of the access unit.

11. An information processing method of an information processing device comprising the steps of:

holding in a holder N hold information for pictures (N is an integer equal to or larger than one) including hold information for a reference picture, necessary for decoding of an access unit, as a processing subject when decoding of stream data composed of a plurality of access units in units of the access unit, the access unit including actual data of a coded picture and including a header that allows specifying whether a reference picture is necessary for decoding of the picture and allows specifying of the reference picture if the reference picture is needed;

analyzing the entire stream data when input, prior to the stream data being decoded, to detect the header for each of the access units; and

creating, prior to decoding the stream data, a list of hold information indicating the N hold information for the pictures to be held by the holder at a stage of decoding for each of the access units included in the stream data, the list created prior to decoding the stream data by using the header detected by processing of the step of analyzing the stream data in units of the access unit.