Method and apparatus for decoding/encoding a video signal
The present invention provides a method of decoding a video signal. The method includes the steps of checking an encoding scheme of the video signal, obtaining configuration information for the video signal according to the encoding scheme, recognizing a total number of views using the configuration information, recognizing inter-view reference information based on the total number of the views, and decoding the video signal based on the inter-view reference information, wherein the configuration information includes at least view information for identifying a view of the video signal.
1. A method for decoding multi-view video data in a multi-view video stream with a decoding apparatus, comprising:
receiving, with the decoding apparatus, the multi-view video stream, the multi-view video stream including a random access picture, the random access picture being a coded picture in which all slices reference only slices having a same time as the random access picture;
obtaining, with the decoding apparatus, a random access flag for inter-view prediction from the multi-view video stream, the random access flag indicating whether a type of picture is the random access picture;
obtaining, with the decoding apparatus, initialization information of a reference picture list, the initialization information representing view dependency relationships between a plurality of views, the initialization information including view number information and view identification information for the plurality of views, the view number information indicating a number of reference pictures referred for inter-view prediction of the random access picture, the view identification information identifying to which of the plurality of views each of the reference pictures belongs;
initializing, with the decoding apparatus, the reference picture list, the initializing including assigning an inter-view reference index to the reference picture based on the random access flag, the view number information and the view identification information, the inter-view reference index identifying the reference picture in the initialized reference picture list used for inter-view prediction of a block to be decoded in the random access picture, the block to be decoded having a same time with the reference picture and a different view from the reference picture;
obtaining, with the decoding apparatus, modification information for the initialized reference picture list from the multi-view video stream, the modification information representing how to change the inter-view reference index assigned to the reference picture in the initialized reference picture list;
modifying, with the decoding apparatus, the initialized reference picture list for inter-view prediction, by changing the inter-view reference index assigned to the reference picture based on the modification information;
determining, with the decoding apparatus, a prediction value of a current macroblock in the random access picture based on the modified reference picture list; and
decoding, with the decoding apparatus, the current macroblock using the prediction value,
wherein the modification information is obtained from a slice header.
2. The method of claim 1 , wherein the multi-view video data includes video data of a base view independent of other views, the base view being a view decoded without using inter-view prediction.
3. The method of claim 1 , wherein the inter-view reference index is changed by performing a subtraction operation or an addition operation between a view information difference and a predicted inter-view reference index,
wherein the view information difference means a difference between an inter-view reference index of a current reference picture in the initialized reference picture list and the predicted inter-view reference index, and
wherein the predicted inter-view reference index indicates an inter-view reference index assigned to the reference picture to be changed right before the current reference picture.
4. The method of claim 1 , wherein the modifying step shifts other pictures in the initialized reference picture list to later positions in the initialized reference picture list.
5. An apparatus for decoding multi-view video data in a multi-view video stream, comprising:
a parsing unit configured to receive the multi-view video stream, the multi-view video stream including a random access picture, the random access picture being a coded picture in which all slices reference only slices having a same time as the random access picture, the parsing unit configured to obtain a random access flag for inter-view prediction, the random access flag indicating whether a type of picture is the random access picture, the parsing unit configured to obtain initialization information of a reference picture list, the initialization information representing view dependency relationships between a plurality of views, the initialization information including view number information and view identification information, the view number information indicating a number of reference pictures referred for inter-view prediction of the random access picture, the view identification information identifying to which of the plurality of views each of the reference pictures belongs;
a decoded picture buffer unit configured to initialize the reference picture list, the initializing including assigning an inter-view reference index to the reference picture based on the random access flag, the view number information and the view identification information, the inter-view reference index identifying the reference picture in the initialized reference picture list used for inter-view prediction of a block to be decoded in the random access picture, the block to be decoded having a same time with the reference picture and a different view from the reference picture, and configured to obtain modification information for the initialized reference picture list from the multi-view video stream, the modification information representing how to change the inter-view reference index assigned to the reference picture in the initialized reference picture list, and configured to modify the initialized reference picture list for inter-view prediction, by changing the inter-view reference index assigned to the reference picture based on the modification information; and
an inter-prediction unit configured to determine a prediction value of a current macroblock in the random access picture based on the modified reference picture list, and configured to decode the current macroblock using the prediction value,
wherein the modification information is obtained from a slice header.
6. The apparatus of claim 5 , wherein the multi-view video data includes video data of a base view independent of other views, the base view being a view decoded without using inter-view prediction.
7. The apparatus of claim 5 , wherein the inter-view reference index is changed by performing a subtraction operation or an addition operation between a view information difference and a predicted inter-view reference index,
wherein the view information difference means a difference between an inter-view reference index of a current reference picture in the initialized reference picture list and the predicted inter-view reference index, and
wherein the predicted inter-view reference index indicates an inter-view reference index assigned to the reference picture to be changed right before the current reference picture.
8. The apparatus of claim 5 , wherein the decoded picture buffer unit is configured to shift other pictures in the initialized reference picture list to later positions in the initialized reference picture list.