An apparatus for facilitating reception of multiple representations of a video signal. In one embodiment, the apparatus includes a mechanism for receiving plural representations of the video signal corresponding to plural decimated versions of the video signal, associating pictures of the received plural representations of the video signal, and outputting pictures corresponding to information from associated pictures in accordance with a relative temporal order.

An apparatus for facilitating reception of multiple representations of a video signal. In one embodiment, the apparatus includes a mechanism for receiving plural representations of the video signal corresponding to plural decimated versions of the video signal, associating pictures of the received plural representations of the video signal, and outputting pictures corresponding to information from associated pictures in accordance with a relative temporal order.

A method and apparatus for error detection. The method includes decoding slice header when a unit is a NAL unit, decoding a macroblock unit and detecting an end of slice flag setting indicating end of slice, decoding RBSP (Raw Byte Sequence Payload) trailing bits and determining if it is end of slice, and determining an error occurred when it is not end of slice. The apparatus configured to decoding via a digital processor a slice header when a unit is a NAL unit, decoding a macroblock unit and detecting an end of slice flag setting indicating an end of slice, decoding RBSP trailing bits and determining if it is the end of slice, and determining an error occurred when it is not end of slice.

A method and apparatus for error detection. The method includes decoding slice header when a unit is a NAL unit, decoding a macroblock unit and detecting an end of slice flag setting indicating end of slice, decoding RBSP (Raw Byte Sequence Payload) trailing bits and determining if it is end of slice, and determining an error occurred when it is not end of slice. The apparatus configured to decoding via a digital processor a slice header when a unit is a NAL unit, decoding a macroblock unit and detecting an end of slice flag setting indicating an end of slice, decoding RBSP trailing bits and determining if it is the end of slice, and determining an error occurred when it is not end of slice.

A macroblock in a video sequence may be undecodable because the corresponding compressed data is lost or the syntax is out of synchronization. An undecodable macroblock may be concealed using error concealment technique. The level of initial visible artifacts caused by undecodable macroblocks may be estimated as a function of motion magnitude, error concealment distance, and/or residual energy. The initial visible artifacts may propagate spatially or temporally to other macroblocks through prediction. Considering both initial visible artifacts and propagated artifacts, levels of overall artifacts may be estimated for individual macroblocks. The visual quality for the video sequence can then be estimated by pooling the macroblock level artifact levels.

A macroblock in a video sequence may be undecodable because the corresponding compressed data is lost or the syntax is out of synchronization. An undecodable macroblock may be concealed using error concealment technique. The level of initial visible artifacts caused by undecodable macroblocks may be estimated as a function of motion magnitude, error concealment distance, and/or residual energy. The initial visible artifacts may propagate spatially or temporally to other macroblocks through prediction. Considering both initial visible artifacts and propagated artifacts, levels of overall artifacts may be estimated for individual macroblocks. The visual quality for the video sequence can then be estimated by pooling the macroblock level artifact levels.

Methods and encoders for tracing an error in a frame of a video to a subsequent frame of the video. In response to receiving an error notification message indicating an error has occurred in an encoded frame during decode, an encoder obtains: (a) the minimum and maximum horizontal motion vector components for each column of blocks of the frame immediately following the error frame; and (b) the minimum and maximum vertical motion vector components for each row of blocks of the frame immediately following the error frame. A rectangular region of blocks of the frame immediately following the error frame that the error is likely to have propagated to is identified using the minimum and maximum horizontal and vertical motion vector components.

Methods and encoders for tracing an error in a frame of a video to a subsequent frame of the video. In response to receiving an error notification message indicating an error has occurred in an encoded frame during decode, an encoder obtains: (a) the minimum and maximum horizontal motion vector components for each column of blocks of the frame immediately following the error frame; and (b) the minimum and maximum vertical motion vector components for each row of blocks of the frame immediately following the error frame. A rectangular region of blocks of the frame immediately following the error frame that the error is likely to have propagated to is identified using the minimum and maximum horizontal and vertical motion vector components.

In some embodiments, techniques for computer security comprise receiving an email message; determining a sender of the email message; determining whether the sender of the email message is trusted, wherein determining whether the sender of the email message is trusted includes determining whether the sender of the email message is associated with a whitelist; retrieving domain-related information by performing a DNS query on a domain associated with the sender; based at least in part on the domain-related information, determining whether the sender of the email message is verified; determining whether the sender is both trusted and verified; and when it is determined that the sender is both trusted and verified, treating the email message as trustworthy, wherein treating the email message as trustworthy includes bypassing a classifier.

The present disclosure discloses an image frame error concealment method including the following steps: determining whether an nth image frame has a packet loss error, and if so, not performing error concealment on the nth image frame; and performing error concealment on an (n+1)th image frame, wherein the error concealment operation is performed with reference to one or more image frames before the nth image frame, wherein n is an integer greater than or equal to 2.