Inter-prediction concept using tile-independency constraints

A block-based video decoder supporting motion-compensated bi-directional prediction and comprising a bi-directional optical flow tool for improving the motion-compensated bi-directional prediction, wherein the block-based video decoder is configured to

• deactivate the bi-directional optical flow tool depending on whether at least one of first and second patches of a predetermined inter-predicted block of a current picture to be subject to motion-compensated bi-directional prediction, which are displaced relative to the predetermined inter-predicted block according to first and second motion vectors signaled in the data stream for the predetermined inter-predicted block, crosses boundaries of a tile of the current picture by which the predetermined inter-predicted block is comprised, or
• use boundary padding so as to fill a portion of first and second patches of a predetermined inter-predicted block of a current picture to be subject to the motion-compensated bi-directional prediction, which are displaced relative to the predetermined inter-predicted block according to first and second motion vectors signaled in the data stream for the predetermined inter-predicted block, which portion lies beyond boundaries of a tile of the current picture, by which the predetermined inter-predicted block is comprised.

A block-based video encoder for encoding a video into a data stream and supporting motion-compensated prediction configured to

• determine motion information for a predetermined inter-predicted block of a current picture of a video, which locates a patch in a reference picture, from which the predetermined inter-predicted block is to be predicted, in a manner so that the patch is within, and does not cross, boundaries of a tile by which the predetermined inter-predicted block is comprised,
• predict the predetermined inter-predicted block using the motion information from the patch of the reference picture,
• encode the motion information into the data stream, so that a signalization thereof into the data stream is to be performed depending on a position of boundaries between tiles, into which the video is spatially partitioned.

A block-based video encoder supporting motion-compensated bi-directional prediction and comprising a bi-directional optical flow tool for improving the motion-compensated bi-directional prediction, wherein the block-based video encoder is configured to

• deactivate the bi-directional optical flow tool depending on whether at least one of first and second patches of a predetermined inter-predicted block of a current picture to be subject to motion-compensated bi-directional prediction, which are displaced relative to the predetermined inter-predicted block according to first and second motion vectors signaled in the data stream for the predetermined inter-predicted block, crosses boundaries between tiles, into which the video is spatially partitioned, or
• use boundary padding so as to fill a portion of first and second patches of a predetermined inter-predicted block of a current picture to be subject to the motion-compensated bi-directional prediction, which are displaced relative to the predetermined inter-predicted block according to first and second motion vectors signaled in the data stream for the predetermined inter-predicted block, which portion lies beyond boundaries of a tile of the current picture, by which the predetermined inter-predicted block is comprised.

A method for block-based video decoding that supports motion-compensated prediction, comprising:

• deriving motion information for a predetermined inter-predicted block of a current picture of a video, which locates a patch in a reference picture, from which the predetermined inter-predicted block is to be predicted, from a data stream into which the video is coded, depending on a position of boundaries between tiles, into which the video is spatially partitioned, and
• predicting the predetermined inter-predicted block using the motion information from the patch of the reference picture.

A method for block-based video decoding that supports motion-compensated bi-directional prediction and comprising a bi-directional optical flow tool for improving the motion-compensated bi-directional prediction, the method comprising:

• deactivating the bi-directional optical flow tool depending on whether at least one of first and second patches of a predetermined inter-predicted block of a current picture to be subject to motion-compensated bi-directional prediction, which are displaced relative to the predetermined inter-predicted block according to first and second motion vectors signaled in the data stream for the predetermined inter-predicted block, crosses boundaries of a tile of the current picture by which the predetermined inter-predicted block is comprised, or
• using boundary padding so as to fill a portion of first and second patches of a predetermined inter-predicted block of a current picture to be subject to the motion-compensated bi-directional prediction, which are displaced relative to the predetermined inter-predicted block according to first and second motion vectors signaled in the data stream for the predetermined inter-predicted block, which portion lies beyond boundaries of a tile of the current picture, by which the predetermined inter-predicted block is comprised.

A method for block-based video encoding for encoding a video into a data stream and supporting motion-compensated prediction, comprising:

• determining motion information for a predetermined inter-predicted block of a current picture of a video, which locates a patch in a reference picture, from which the predetermined inter-predicted block is to be predicted, in a manner so that the patch is within, and does not cross, boundaries of a tile by which the predetermined inter-predicted block is comprised,
• predicting the predetermined inter-predicted block using the motion information from the patch of the reference picture,
• encoding the motion information into the data stream, so that a signalization thereof into the data stream is to be performed depending on a position of boundaries between tiles, into which the video is spatially partitioned.

A method for block-based video encoding that supports motion-compensated bi-directional prediction and comprising a bi-directional optical flow tool for improving the motion-compensated bi-directional prediction, the method comprising:

• deactivating the bi-directional optical flow tool depending on whether at least one of first and second patches of a predetermined inter-predicted block of a current picture to be subject to motion-compensated bi-directional prediction, which are displaced relative to the predetermined inter-predicted block according to first and second motion vectors signaled in the data stream for the predetermined inter-predicted block, crosses boundaries between tiles, into which the video is spatially partitioned, or
• using boundary padding so as to fill a portion of first and second patches of a predetermined inter-predicted block of a current picture to be subject to the motion-compensated bi-directional prediction, which are displaced relative to the predetermined inter-predicted block according to first and second motion vectors signaled in the data stream for the predetermined inter-predicted block, which portion lies beyond boundaries of a tile of the current picture, by which the predetermined inter-predicted block is comprised.