Abstract: An antenna arrangement can produce omni-directional polarisations of two or more types and comprises a compact arrangement of a dipole with array comprising first and second conductors in parallel planes separated by a printed circuit board and laid on the printed circuit board for generating horizontally polarised signals. A monopole arrangement comprises a third conductor substantially orthogonal to the planes of the first and second conductors and arranged so that one of the first and second conductors acts as a ground plane for the third conductor.

Abstract: A video decoder has a transform mode and a transform skip mode and in the transform skip mode a residual prediction mode is selected. A compressed bit-stream is entropy-decoded to obtain a block of quantised values. An inverse quantiser operates in the transform mode to form transform coefficients and in the transform skip mode to form differential residual values. In the transform mode an inverse transform is performed to form residual values. In the transform skip mode residual prediction is used perform residual prediction using high accuracy locally decoded residual value. The residual value is then down-scaled to obtain the reconstructed residual. A block predictor is formed from decoded image values at the same precision at which video samples are stored in the frame memory.

Abstract: A graphical user interface for a computer program, the interface comprising an array of main panes each providing access to a particular aspect of the program, the panes being in register with one another at a vertex corresponding to the area in which all the panes meet, each of the panes being adapted to expand as a pointing device highlights a pane, the expansion of said pane relative to the other panes wherein the panes remain in register with one another at the vertex as a pane expands.

Abstract: In a method of video coding, in which a difference is formed between input picture values and picture prediction values and that difference is transforming with a DCT, the picture prediction is formed as: P=(1?c)Pc+CPo where Pc is a closed loop predictor which is restricted to prediction values capable of exact reconstruction in a downstream decoder and Po is a spatial predictor which is not restricted to prediction values capable of exact reconstruction. The factor can vary from zero to unity depending on a variety of parameters.

Abstract: This invention relates to a system (2000) for providing individual users access to audio/visual content which has been broadcast to a plurality of users on a scheduled basis. The system comprises means for storing the content, means for enabling a user to download the content in the form of a downloadable file, and means for enabling a user to view the content by opening and playing the downloaded file. The means for opening and playing the downloaded file preferably being adapted to open and/or play the downloaded file only within a fixed time period after the scheduled broadcast time of the content.

Abstract: An interleaver or deinterleaver comprises a memory having M logical memory units arranged in groups of N memory units such that accesses to memory units within a group are faster after a first access to a memory in that group using first access. An address generator is arranged to write consecutive data items a number of memory units apart that is less than the size of groups N of memory units so that two or more data items are written within groups. The arrangement provides fast interleaving without increasing memory size.

Abstract: Video is encoded by applying a vertically and horizontally separable transform to provide a block of transform coefficients; and quantizing the transform coefficients. Prior to quantization, a filtering operation is performed on the block of transform coefficients, the filtering operation applying a rotation to pairs of coefficients in the block. Each pair of coefficients may be symmetrically positioned with respect to the leading diagonal of the block.

Abstract: This invention relates to a system (2000) for providing individual users access to audio/visual content which has been broadcast to a plurality of users on a scheduled basis. The system comprises means for storing the content, means for enabling a user to download the content in the form of a downloadable file, and means for enabling a user to view the content by opening and playing the downloaded file. The means for opening and playing the downloaded file preferably being adapted to open and/or play the downloaded file only within a fixed time period after the scheduled broadcast time of the content.

Abstract: In the encoding of video data, a list of references pictures is constructed to be used in decoding. Prediction (direction) modes are defined by n-tuples (x0, x1, . . . , xM-1), where xm specifies prediction option of the m-th component of the motion vector field, m=0, . . . , M-1, where M components to the motion fields exist; where a coding option xm is an element from a set composed of all defined combinations of motion prediction modes and reference picture indices, with the addition of an option “/”, xm?{“/”, 0, 1, . . . , rm?1}; where option “/” specifies that the component is not used, and other options 0, 1, . . . , rm?1 specify one of rm combinations. A subset of all possible n-tuples is provided and a prediction mode used for predicting an inter-coded block is defined by reference to that subset.

Abstract: A method and transmitter and receiver for determining and transmitting or receiving a non-uniform QAM signal comprises selecting a signal to noise ratio for a channel and forward error corrector and then determining positions of constellation points that maximise a measure of channel capacity at the selected signal to noise ratio. The position of one constellation point and another constellation point within the constellation are constrained to be equal to one another prior to determining the positions of the constellation points. In doing so, a so called condensed QAM constellation arrangement may be derived having fewer than conventional number of constellation points for a given QAM scheme. The condensed QAM arrangement has improved performance at certain signal to noise ratios.

Abstract: Video encoding or decoding utilizing a spatial transform operating on rows and columns of a block, with a set of transform skip modes including: transform on rows and columns; transform on rows only; transform on columns only; no transform. An indication of the selected mode is provided to the decoder. Coefficients are scaled by a factor dependent upon the norm of the transform vector of the skipped transform to bring the untransformed image values to the same level as transformed coefficients.

Abstract: Video encoding or decoding utilising a spatial transform operating on rows and columns of a block, with a set of transform skip modes including: transform on rows and columns; transform on rows only; transform on columns only; no transform. An indication of the selected mode is provided to the decoder. Coefficients are scaled by a factor dependent upon the norm of the transform vector of the skipped transform to bring the untransformed image values to the same level as transformed coefficients.

Abstract: In video coding, where differences between input picture values and picture prediction values are transformed in a block based transform, the differences are formed in a series of parallel steps. A first step conducted in parallel upon a first subset of pixels uses prediction values based wholly on previously processed blocks. This first subset can include anchor pixels which are not contiguous with any previously processed block. A second step conducted in parallel upon a second subset includes pixels which are predicted from pixels of the first subset.

Abstract: This present invention relates to a system for providing users access to audio/visual content. The system comprises means for enabling a plurality of users to connect to the system, means for enabling users to browse available content items; means for receiving a message from at least one user connected to the system, and means for transmitting said message to at least one further user connected to the system. The system also provides means for enabling connected users to synchronise consumption of available content items.

Abstract: An image encoder utilising a transformation operating between a spatial domain and a DCT or other transform domain, employs the steps of forming a prediction; subtracting the prediction to form a difference; and quantising the difference in a transform domain, where the prediction is formed in the transform domain and the transform domain prediction is weighted.

Abstract: A system for processing audio-video data to produce metadata, has an input for receiving audio video data. A characteristic extraction unit is arranged to extract n multiple distinct characteristics from the received audio-video data. A data comparison unit is arranged to compare the n multiple distinct characteristics with data extracted from example audio-video data by comparing in n dimensional space to produce a value for each of f features of the audio-video data where f<n. A multi-dimensional metadata unit is arranged to receive the values for each feature and to produce a complex continuous metadata value of M dimensions for the audio-video data where M<f.

Abstract: An interleaver or deinterleaver comprises a memory having M logical memory units arranged in groups of N memory units such that accesses to memory units within a group are faster after a first access to a memory in that group using first access. An address generator is arranged to write consecutive data items a number of memory units apart that is less than the size of groups N of memory units so that two or more data items are written within groups. The arrangement provides fast interleaving without increasing memory size.

Abstract: In the encoding of video data, a list of references pictures is constructed to be used in decoding. Prediction (direction) modes are defined by n-tuples (x0, x1, . . . , xM-1), where xm specifies prediction option of the m-th component of the motion vector field, m=0, . . . , M-1, where M components to the motion fields exist; where a coding option xm is an element from a set composed of all defined combinations of motion prediction modes and reference picture indices, with the addition of an option “/”, xm?{“/”, 0, 1, . . . , rm?1}; where option “/” specifies that the component is not used, and other options 0, 1, . . . , rm?1 specify one of rm combinations. A subset of all possible n-tuples is provided and a prediction mode used for predicting an inter-coded block is defined by reference to that subset.

Abstract: A mechanism for dynamically resolving polymorphic type dependencies between parallel heterogenous run-time environments is provided. The mechanism comprises a registry of class types for software objects, in which each class type is linked to a hierarchy of bindings rooted at the binding for that class type with descendent bindings in the hierarchy relating to more specific sub-classes. At run-time a pointer to an object is received, and the received static type of that pointer can be looked up in the registry to determine the location in the hierarchy of bindings at which to make an initial query for the most specific sub-class compatible with the dynamic type of the object. Subsequently, beginning at the determined location in the hierarchy of bindings, the most specific sub-class compatible with the dynamic type of the object is determined, and a run-time binding based on the most specific sub-class identified can be selected.

Abstract: In a method of video coding, in which a difference is formed between input picture values and picture prediction values and that difference is transforming with a DCT, the picture prediction is formed as: P=(1?c)Pc+CPo where Pc is a closed loop predictor which is restricted to prediction values capable of exact reconstruction in a downstream decoder and Po is a spatial predictor which is not restricted to prediction values capable of exact reconstruction. The factor can vary from zero to unity depending on a variety of parameters.