Abstract: The techniques and mechanisms described herein are directed at transmitting elementary streams in a broadcast environment. The mechanisms provide a buffer controller and packet scheduler that allow a media format to be transmitted through the broadcasting environment in a manner resulting in a low channel switch delay. A buffer-fullness indicator allows the operation with various types of decoders. A lower bound and an upper bound are calculated for each frame within the elementary stream. The lower bound corresponds to an earliest time for sending the frame without causing an overflow condition within a decoder buffer. The upper bound corresponds to a latest time for sending the frame without causing an underflow condition within the decoder buffer. A send time is then scheduled based on the lower bound and the upper bound that determines when a packet associated with the frame is transmitted over a channel in a broadcast environment.

Abstract: A device or method for video compression uses a technique in which changes in the image are encoded by motions of block of the image and signals indicating evolutions in the block. To determine the motions of the blocks of a each frame, a search is performed for a similar block of a previous frame based on points of the previous frame which are arranged in successive diamond shaped zones. The diamond shaped zones may be centred on the position of the block in previous frame, or one or more predicted motions of the block. The method terminates according to criteria defined using thresholds.

Abstract: Systems and methods are described for using peer-to-peer collaboration to enhance streaming of multimedia content. A peer-paired pyramid streaming (P3S) architecture is introduced that is a hybrid of a client/server structure and a peer-to-peer structure. Clients are hierarchically organized and those that are in the same level are coupled to form peer-pairs. The peers in a peer-pair cooperate by utilizing a connection between them. Streaming is enhanced by allowing each peer to download different portions of a stream and sharing portions not in possession of the other. Error recovery is enhanced by allowing a peer to retrieve a dropped packet from its corresponding peer. A colored overlay is used with a P3S structure to improve streaming throughput.

Abstract: An accelerated video decoding system utilizes a graphics processing unit to perform motion compensation, image reconstruction, and color space conversion processes, while utilizing a central processing unit to perform other decoding processes.

Abstract: A video encoding system performs packetization of FGS/PFGS encoded video bitstreams by selecting encoded bitstream segments for packetization based on an estimated total contribution to distortion reduction associated with each encoded bitstream segment. The selected bitstream segments are then packetized according to a packet-independence packetization strategy that minimizes inter-packet dependency.

Abstract: It is known to represent a square block of an image which has a maximum horizontal or vertical extension N as N vectors each representing one column or row, and encode it using an N×N discrete cosine transform matrix. We introduce a technique which transforms an input vector, or array, representing a portion of an arbitrarily-shaped object block in which the maximum horizontal or vertical extension is at most N, by adding to it additional padding elements, to produce a vector or array which can be encoded using an N×N discrete cosine transform. The padding maximises the number of transformed elements which are zero. We propose encoding arbitrarily-shaped objects based on this padding technique.