Video coding methods for time motion vector prediction, interlayer referencing, and time sublayer instruction.

Abstract

The present invention provides a decoder, encoder, decoding method, encoding method, and program for determining a reference image for interpreting motion vectors in a multilayer video data stream. [Solution] The encoder 10 encodes the video sequence 12 into a video bitstream 14. The video sequence 12 includes a sequence of images 21, which are arranged in presentation order or image order 17. The encoder also forms the encoded video sequence 20 in the form of access units 22, each access unit 22 encoding video data therein that belongs to a common time point and includes one or more encoded images 26. The decoder 50 decodes the video bitstream 14 to obtain the decoded video sequence 20'.

Claims

1. A decoder (50) for decoding a multilayer video bitstream (14) representing an encoded video sequence (20), wherein the multilayer video bitstream (14) includes an access unit (22), each access unit (22) includes one or more images of the encoded video sequence (20), each of the images belongs to one of the layers of the multilayer video bitstream (14), and each of the access units (22) is a time sublayer (22) of the set of time sublayers of the encoded video sequence (20). １ , 22 ２ ) belongs to the category, and the decoder (50) is From the aforementioned multilayer video bitstream (14), A video parameter set (91) including one or more bitstream compatibility sets (86), one or more buffer requirement sets (84), and one or more decoder requirement sets (82), An OLS (83) of the multilayer video bitstream (14), wherein an OLS instruction (81) of the OLS (83) indicates a subset of the layers of the multilayer video bitstream (14), and the OLS instruction (81) associates the OLS with a corresponding one of the bitstream compatibility set (86), the buffer requirements set (84), and the decoder requirements set (82), It is configured to derive the following: The bitstream compatibility set (86) associated with the OLS (83) includes a time subset instruction indicating a constraint (96) on the maximum time sublayer of the bitstream compatibility set (86), The buffer requirement set (84) associated with the OLS (83) includes a time subset instruction indicating a constraint (94) on the maximum time sublayer of the buffer requirement set (84), The decoder requirements set (82) associated with the OLS (83) includes a time subset instruction indicating a constraint (92) on the maximum time sublayer of the decoder requirements set (82), The decoder (50) is, The decoder (50) is configured to determine whether to decode an image belonging to a time sublayer based on whether the time sublayer of the multilayer video bitstream (14) exceeds the maximum time sublayer of the multilayer video bitstream (14) being decoded when decoding a subset of the layers of the multilayer video bitstream (14) indicated by the OLS (83). The decoder (50) is When the decoder (50) receives the maximum time sublayer instruction (99) of the multilayer video bitstream (14), it determines the maximum time sublayer of the multilayer video bitstream (14) to be decoded based on the maximum time sublayer instruction (99) of the multilayer video bitstream (14), If the maximum time sublayer instruction (99) is unavailable, it is inferred that the maximum time sublayer of the multilayer video bitstream (14) to be decoded is equal to the maximum time sublayer indicated by the constraint (92) on the maximum time sublayer of the decoder requirements set (82) associated with the OLS (83). The decoder (50) is configured as described above.

2. From the bitstream compatibility set (86), the buffer requirements set (84), and the decoder requirements set (82) associated with the OLS, a set of parameters associated with the maximum time sublayer of the multilayer video bitstream (14) to be decoded is selected, and The set of parameters is used to adjust one or more of the encoded image buffer size, decoded image buffer size, and buffer scheduling. A decoder (50) according to claim 1, configured as described above.

3. An encoder (10) for providing a multilayer video bitstream (14) representing an encoded video sequence (20), wherein the multilayer video bitstream (14) includes an access unit (22), each access unit (22) includes one or more images of the encoded video sequence (20), each of the images belongs to one of the layers of the multilayer video bitstream (14), and each of the access units (22) includes a time sublayer (22) of the set of time sublayers of the encoded video sequence (20). １ , 22 ２ ) belongs to the category, and the encoder (10) is, In the multilayer video bitstream (14), A video parameter set (91) including one or more bitstream compatibility sets (86), one or more buffer requirement sets (84), and one or more decoder requirement sets (82), An OLS (83) of the multilayer video bitstream (14), wherein an OLS instruction (81) of the OLS indicates a subset of the layers of the multilayer video bitstream (14), and the OLS instruction (81) associates the OLS with a corresponding one of the bitstream compatibility set (86), the buffer requirements set (84), and the decoder requirements set (82), Configured to provide, The bitstream compatibility set (86) associated with the OLS (83) includes a time subset instruction indicating a constraint (96) on the maximum time sublayer of the bitstream compatibility set (86), The buffer requirement set (84) associated with the OLS (83) includes a time subset instruction indicating a constraint (94) on the maximum time sublayer of the buffer requirement set (84), The decoder requirements set (82) associated with the OLS (83) includes a time subset instruction indicating a constraint (92) on the maximum time sublayer of the decoder requirements set (82), The encoder (10) is, The encoder (10) selects the maximum time sublayer of the multilayer video bitstream (14) to be decoded by the decoder (50), and if the maximum time sublayer to be decoded is equal to the maximum time sublayer indicated by the constraint (92) for the maximum time sublayer in the decoder requirements set (82) associated with the OLS, the encoder (10) omits signaling of the instruction (99) for the maximum time sublayer to be decoded in the multilayer video bitstream (14). The encoder (10) is configured as described above.

4. The encoder (10) according to claim 3, configured to provide the instruction (99) for the maximum time sublayer of the multilayer video bitstream (14) if the maximum time sublayer to be decoded is not equal to the maximum time sublayer indicated by the constraint (92) for the maximum time sublayer of the decoder requirements set (82) associated with the OLS (83).

5. A method for decoding (50) a multilayer video bitstream (14) representing an encoded video sequence (20), wherein the multilayer video bitstream (14) includes an access unit (22), each access unit (22) includes one or more images of the encoded video sequence (20), each of the images belongs to one of the layers of the multilayer video bitstream (14), and each of the access units (22) is a time sublayer (22) of the set of time sublayers of the encoded video sequence (20). １ , 22 ２ ) belongs to the category, and the method described above is From the aforementioned multilayer video bitstream (14), A video parameter set (91) including one or more bitstream compatibility sets (86), one or more buffer requirement sets (84), and one or more decoder requirement sets (82), An OLS (83) of the multilayer video bitstream (14), wherein an OLS instruction (81) of the OLS indicates a subset of the layers of the multilayer video bitstream (14), and the OLS instruction (81) associates the OLS with a corresponding one of the bitstream compatibility set (86), the buffer requirements set (84), and the decoder requirements set (82), The purpose is to derive the following: The bitstream compatibility set (86) associated with the OLS includes a time subset instruction indicating a constraint (96) on the maximum time sublayer of the bitstream compatibility set (86), The buffer requirement set (84) associated with the OLS includes a time subset instruction indicating a constraint (94) on the maximum time sublayer of the buffer requirement set (84), The decoder requirements set (82) associated with the OLS includes a time subset instruction indicating a constraint (92) on the maximum time sublayer of the decoder requirements set (82), Including the derivation described above, The method, when decoding a subset of the layers of the multilayer video bitstream (14) shown by the OLS, includes determining whether to decode an image belonging to a time sublayer based on whether the time sublayer of the multilayer video bitstream (14) exceeds the maximum time sublayer of the multilayer video bitstream (14) being decoded, and the method When a maximum time sublayer instruction (99) is received for the multilayer video bitstream (14), the maximum time sublayer of the multilayer video bitstream (14) to be decoded is determined based on the maximum time sublayer instruction (99) received for the multilayer video bitstream (14), If the maximum time sublayer instruction (99) is unavailable, it is inferred that the maximum time sublayer of the multilayer video bitstream (14) to be decoded is equal to the maximum time sublayer indicated by the constraint (92) on the maximum time sublayer of the decoder requirements set (82) associated with the OLS (83), The method, including the method described above.

6. A method (10) for providing a multilayer video bitstream (14) representing an encoded video sequence (20), wherein the multilayer video bitstream (14) includes an access unit (22), each access unit (22) includes one or more images of the encoded video sequence (20), each of the images belongs to one of the layers of the multilayer video bitstream (14), and each of the access units (22) includes a time sublayer (22) of the set of time sublayers of the encoded video sequence (20). １ , 22 ２ ) belongs to the category, and the method described above is In the multilayer video bitstream (14), A video parameter set (91) including one or more bitstream compatibility sets (86), one or more buffer requirement sets (84), and one or more decoder requirement sets (82), An OLS (83) of the multilayer video bitstream (14), wherein an OLS instruction (81) of the OLS indicates a subset of the layers of the multilayer video bitstream (14), and the OLS instruction (81) associates the OLS with a corresponding one of the bitstream compatibility set (86), the buffer requirements set (84), and the decoder requirements set (82), To provide, The bitstream compatibility set (86) associated with the OLS includes a time subset instruction indicating a constraint (96) on the maximum time sublayer of the bitstream compatibility set (86), The buffer requirement set (84) associated with the OLS includes a time subset instruction indicating a constraint (94) on the maximum time sublayer of the buffer requirement set (84), The decoder requirements set (82) associated with the OLS includes a time subset instruction indicating a constraint (92) on the maximum time sublayer of the decoder requirements set (82), Including the provision described above, The method includes selecting the maximum time sublayer of the multilayer video bitstream (14) to be decoded by the decoder (50), and omitting the signaling of the instruction (99) for the maximum time sublayer to be decoded in the multilayer video bitstream (14) if the maximum time sublayer to be decoded is equal to the maximum time sublayer indicated by the constraint (92) for the maximum time sublayer of the decoder requirements set (82) associated with the OLS. The method, including the method described above.

7. A computer program for implementing any of the methods described in claim 5 or 6 when executed on a computer or signal processor.

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