Abstract: A method of motion vector prediction for use in differential motion vector coding within a block motion-compensation-based video coder. The video coder employs a generalized multiple reference picture buffer which may contain multiple reference pictures in both the forward and backward temporal direction from the current picture. For the purpose of coding selections of reference pictures within the buffer, the pictures are organized into two, potentially overlapping, lists of reference pictures. The prediction of a motion vector that selects a reference picture using a given reference picture list is not dependent upon any motion vectors that select their reference pictures using the other reference picture list. The values of spatially neighboring motion vectors that use the same list of reference pictures as the motion vector being predicted are used for prediction, regardless of the relative temporal direction of the current and neighboring motion vectors.

Abstract: Systems, methods and apparatus are provided for computing quality scores for a media session delivered using an adaptive streaming protocol, where the quality score may be an estimate of a mean opinion score. The quality score reflects the impact of network delivery on a viewer's quality of experience (QoE). In particular, the quality score is generally based on the effects of stream switch events, as stream switches may be the result of impaired network delivery. Other network events, such as re-buffering events may also be incorporated in the score.

Abstract: Systems and methods of controlling access to a multimedia stream in a media streaming session from a multimedia server to a requesting device via a network. The systems and methods facilitate receiving a primary request for the multimedia stream from the requesting device; determining whether to allow access to the primary request from the requesting device in accordance with at least one media session policy; and if access is permitted, then generating a secondary request corresponding to the primary request; providing the secondary request to the multimedia server; receiving a first multimedia stream from the multimedia server in response to the secondary request; determining whether to transmit the first multimedia stream or a second multimedia stream based on the at least one media session policy; and transmitting either the first multimedia stream or the second multimedia stream to the requesting device as indicated by the at least one media session policy.

Abstract: Methods and systems for transcoding from an input media stream to an output media stream, wherein the input media stream and the output media stream are in an indexed file format. The methods and systems are capable of generating an efficiently coded media file where the movie box is generated and sent before transcoding is complete, while maintaining acceptable and consistent quality throughout and minimizing the total size of the file.

Abstract: A method of motion vector prediction for use in differential motion vector coding within a block motion-compensation-based video coder. The video coder employs a generalized multiple reference picture buffer which may contain multiple reference pictures in both the forward and backward temporal direction from the current picture. For the purpose of coding selections of reference pictures within the buffer, the pictures are organized into two, potentially overlapping, lists of reference pictures. The prediction of a motion vector that selects a reference picture using a given reference picture list is not dependent upon any motion vectors that select their reference pictures using the other reference picture list. The values of spatially neighbouring motion vectors that use the same list of reference pictures as the motion vector being predicted are used for prediction, regardless of the relative temporal direction of the current and neighbouring motion vectors.

Abstract: A method of motion vector prediction for use in differential motion vector coding within a block motion-compensation-based video coder. The video coder employs a generalized multiple reference picture buffer which may contain multiple reference pictures in both the forward and backward temporal direction from the current picture. For the purpose of coding selections of reference pictures within the buffer, the pictures are organized into two, potentially overlapping, lists of reference pictures. The prediction of a motion vector that selects a reference picture using a given reference picture list is not dependent upon any motion vectors that select their reference pictures using the other reference picture list. The values of spatially neighboring motion vectors that use the same list of reference pictures as the motion vector being predicted are used for prediction, regardless of the relative temporal direction of the current and neighboring motion vectors.

Abstract: Systems, methods and apparatus are provided for computing quality scores for a media session delivered using an adaptive streaming protocol, where the quality score may be an estimate of a mean opinion score. The quality score reflects the impact of network delivery on a viewer's quality of experience (QoE). In particular, the quality score is generally based on the effects of stream switch events, as stream switches may be the result of impaired network delivery. Other network events, such as re-buffering events may also be incorporated in the score.

Abstract: A method of filtering to remove coding artifacts introduced at block edges in a block-based video coder, the method having the steps of: checking the content activity on every line of samples belonging to a boundary to be filtered and where content activity is based on a set of adaptively selected thresholds determined using Variable-Shift Table Indexing (VSTI); determining whether the filtering process will modify the sample values on that particular line based on said content activity; and selecting a filtering mode between at least two filtering modes to apply on a block boundary basis, implying that there would be no switching between the two primary modes on a line by line basis along a given block boundary. The two filtering modes include a default mode based on a non-recursive filter, and a strong filtering mode which features two strong filtering sub-modes and a new selection criterion that is one-sided with respect to the block boundary to determine which of the two strong filtering sub-modes to use.

Abstract: A method of filtering to remove coding artifacts introduced at block edges in a block-based video coder, the method having the steps of: checking the content activity on every line of samples belonging to a boundary to be filtered and where content activity is based on a set of adaptively selected thresholds determined using Variable-Shift Table Indexing (VSTI); determining whether the filtering process will modify the sample values on that particular line based on said content activity; and selecting a filtering mode between at least two filtering modes to apply on a block boundary basis, implying that there would be no switching between the two primary modes on a line by line basis along a given block boundary. The two filtering modes include a default mode based on a non-recursive filter, and a strong filtering mode which features two strong filtering sub-modes and a new selection criterion that is one-sided with respect to the block boundary to determine which of the two strong filtering sub-modes to use.

Abstract: A method of filtering to remove coding artifacts introduced at block edges in a block-based video coder, the method having the steps of: checking the content activity on every line of samples belonging to a boundary to be filtered and where content activity is based on a set of adaptively selected thresholds determined using Variable-Shift Table Indexing (VSTI); determining whether the filtering process will modify the sample values on that particular line based on said content activity; and selecting a filtering mode between at least two filtering modes to apply on a block boundary basis, implying that there would be no switching between the two primary modes on a line by line basis along a given block boundary. The two filtering modes include a default mode based on a non-recursive filter, and a strong filtering mode which features two strong filtering sub-modes and a new selection criterion that is one-sided with respect to the block boundary to determine which of the two strong filtering sub-modes to use.

Abstract: A method of motion vector prediction for use in differential motion vector coding within a block motion-compensation-based video coder. The video coder employs a generalized multiple reference picture buffer which may contain multiple reference pictures in both the forward and backward temporal direction from the current picture. For the purpose of coding selections of reference pictures within the buffer, the pictures are organized into two, potentially overlapping, lists of reference pictures. The prediction of a motion vector that selects a reference picture using a given reference picture list is not dependent upon any motion vectors that select their reference pictures using the other reference picture list. The values of spatially neighbouring motion vectors that use the same list of reference pictures as the motion vector being predicted are used for prediction, regardless of the relative temporal direction of the current and neighbouring motion vectors.

Abstract: A method of motion vector prediction for use in differential motion vector coding within a block motion-compensation-based video coder. The video coder employs a generalized multiple reference picture buffer which may contain multiple reference pictures in both the forward and backward temporal direction from the current picture. For the purpose of coding selections of reference pictures within the buffer, the pictures are organized into two, potentially overlapping, lists of reference pictures. The prediction of a motion vector that selects a reference picture using a given reference picture list is not dependent upon any motion vectors that select their reference pictures using the other reference picture list. The values of spatially neighbouring motion vectors that use the same list of reference pictures as the notion vector being predicted are used for prediction, regardless of the relative temporal direction of the current and neighbouring motion vectors.

Abstract: A method of filtering to remove coding artifacts introduced at block edges in a block-based video coder, the method having the steps of: checking the content activity on every line of samples belonging to a boundary to be filtered and where content activity is based on a set of adaptively selected thresholds determined using Variable-Shift Table Indexing (VSTI); determining whether the filtering process will modify the sample values on that particular line based on said content activity; and selecting a filtering mode between at least two filtering modes to apply on a block boundary basis, implying that there would be no switching between the two primary modes on a line by line basis along a given block boundary. The two filtering modes include a default mode based on a non-recursive filter, and a strong filtering mode which features two strong filtering sub-modes and a new selection criterion that is one-sided with respect to the block boundary to determine which of the two strong filtering sub-modes to use.

Abstract: A method of filtering to remove coding artifacts introduced at block edges in a block-based video coder, the method having the steps of: checking the content activity on every line of samples belonging to a boundary to be filtered and where content activity is based on a set of adaptively selected thresholds determined using Variable-Shift Table Indexing (VSTI); determining whether the filtering process will modify the sample values on that particular line based on said content activity; and selecting a filtering mode between at least two filtering modes to apply on a block boundary basis, implying that there would be no switching between the two primary modes on a line by line basis along a given block boundary. The two filtering modes include a default mode based on a non-recursive filter, and a strong filtering mode which features two strong filtering sub-modes and a new selection criterion that is one-sided with respect to the block boundary to determine which of the two strong filtering sub-modes to use.

Abstract: A method for transcoding from a VC-1 format to an MPEG-2 format is disclosed. The method generally comprises the steps of (A) decoding an input video stream in the VC-1 format to generate a picture; (B) determining a first mode indicator for the picture; and (C) coding the picture into an output video stream in the MPEG-2 format using one of (i) an MPEG-2 field mode coding and (ii) an MPEG-2 frame mode coding as determined from the first mode indicator.

Abstract: A method for transcoding from an H.264 format to a VC-1 format. The method generally comprises the steps of (A) decoding an input video stream in the H.264 format to generate a picture having a plurality of macroblock pairs that used an H.264 macroblock adaptive field/frame coding; (B) determining a mode indicator for each of the macroblock pairs; and (C) coding the macroblock pairs into an output video stream in the VC-1 format using one of (i) a VC-1 field motion compensation mode coding and (ii) a VC-1 frame motion compensation mode coding as determined from the mode indicator.

Abstract: A method of filtering to remove coding artifacts introduced at block edges in a block-based video coder, the method having the steps of: checking the content activity on every line of samples belonging to a boundary to be filtered and where content activity is based on a set of adaptively selected thresholds determined using Variable-Shift Table Indexing (VSTI); determining whether the filtering process will modify the sample values on that particular line based on said content activity; and selecting a filtering mode between at least two filtering modes to apply on a block boundary basis, implying that there would be no switching between the two primary modes on a line by line basis along a given block boundary. The two filtering modes include a default mode based on a non-recursive filter, and a strong filtering mode which features two strong filtering sub-modes and a new selection criterion that is one-sided with respect to the block boundary to determine which of the two strong filtering sub-modes to use.

Abstract: A method of filtering to remove coding artifacts introduced at block edges in a block-based video coder, the method having the steps of: checking the content activity on every line of samples belonging to a boundary to be filtered and where content activity is based on a set of adaptively selected thresholds determined using Variable-Shift Table Indexing (VSTI); determining whether the filtering process will modify the sample values on that particular line based on said content activity; and selecting a filtering mode between at least two filtering modes to apply on a block boundary basis, implying that there would be no switching between the two primary modes on a line by line basis along a given block boundary. The two filtering modes include a default mode based on a non-recursive filter, and a strong filtering mode which features two strong filtering sub-modes and a new selection criterion that is one-sided with respect to the block boundary to determine which of the two strong filtering sub-modes to use.

Abstract: A method of filtering to remove coding artifacts introduced at block edges in a block-based video coder, the method having the steps of: checking the content activity on every line of samples belonging to a boundary to be filtered and where content activity is based on a set of adaptively selected thresholds determined using Variable-Shift Table Indexing (VSTI); determining whether the filtering process will modify the sample values on that particular line based on said content activity, and selecting a filtering mode between at least two filtering modes to apply on a block boundary basis, implying that there would be no switching between the two primary modes on a line by line basis along a given block boundary. The two filtering modes include a default mode based on a non-recursive filter, and a strong filtering mode which features two strong filtering sub-modes and a new selection criterion that is one-sided with respect to the block boundary to determine which of the two strong filtering sub-modes to use.

Abstract: A method of filtering to remove coding artifacts introduced at block edges in a block-based video coder, the method having the steps of: checking the content activity on every line of samples belonging to a boundary to be filtered and where content activity is based on a set of adaptively selected thresholds determined using Variable-Shift Table Indexing (VSTI); determining whether the filtering process will modify the sample values on that particular line based on said content activity; and selecting a filtering mode between at least two filtering modes to apply on a block boundary basis, implying that there would be no switching between the two primary modes on a line by line basis along a given block boundary. The two filtering modes include a default mode based on a non-recursive filter, and a strong filtering mode which features two strong filtering sub-modes and a new selection criterion that is one-sided with respect to the block boundary to determine which of the two strong filtering sub-modes to use.