Abstract: A video coding method includes for each target image portion to be encoded, selecting a preferred one of a set of encoding modes by optimizing a function comprising an estimate of distortion and a measure of bit rate required to encode the target image portion, the encoding modes comprising at least an intra frame mode and an inter frame mode; and transmitting the encoded video stream over a lossy channel. The estimate of distortion is based on a contribution from possible new loss over the channel comprising possible loss of the target block, and on a contribution from possible past loss over the channel comprising possible loss in a history of the encoded video stream upon which decoding of the target portion depends. The method includes accumulating the contribution from past loss over time, such that the estimate of distortion grows irrespective of the contribution from new loss.

Abstract: A method of encoding an outgoing video stream comprising a plurality of frames, each frame comprising a plurality of image portions, the method including for each target image portion to be encoded, selecting a preferred one of a set of encoding modes by optimizing a function comprising an estimate of distortion and a measure of bit rate required to encode the target image portion; encoding the target image portion into the outgoing video stream using the selected encoding mode; and transmitting the encoded outgoing video stream over a lossy channel. The estimate of distortion comprises a first term representing source coding distortion, and a bias term representing an estimate of distortion that would be experienced due to loss over said channel. The bias term is determined based on a trained parameter trained based on a sample video stream.

Abstract: Methods and systems for controlling a computing-based device based on gestures made within a predetermined range of a camera wherein the predetermined range is a subset of the field of view of the camera. Any gestures made outside of the predetermined range are ignored and do not cause the computing-based device to perform any action. In some examples, the gestures are used to control a drawing canvas that is implemented in a video conference session. In these examples, a single camera may be used to generate an image of a video conference user which is used to detect gestures in the predetermined range and provide other parties to the video conference session a visual image of the user.

Abstract: A method of compressing a video signal. The method comprises: for each of a plurality of image portions, transforming from a spatial domain representation into a transform domain representation; and for each of a plurality of target image portions to be encoded, determining a respective reference portion, determining a prediction of the target image portion based on the reference portion, and encoding the target image portion based on the prediction. The prediction comprises predicting a non-lateral motion of the target image portion relative to the reference portion based on processing of their transform domain coefficients. The encoding comprises generating an encoded bitstream comprising information about the non-lateral motion for use by a decoder.

Abstract: There is disclosed a resource allocation module configured to: allocate a first set of communication event resources for receiving communication event data at the computer device; allocate a second set of communication event resources for transmitting communication event data from the computer device; and reallocate resources from one of said sets to the other of said sets in dependence on an indication of the relative importance of the received communication event data compared to the transmitted communication event data. There is also provided a method and a computer program product.

Abstract: The disclosure relates to a communication client application for running on a user terminal to conduct calls over a network. The client is configured to access a model which models quality of user experience for calls based on a set of technical parameters of each call. The model itself is based on user feedback indicating subjective quality of multiple past calls as experienced by multiple users, modeled with respect to the technical parameters collected from each of the past calls. The model generates a predicted call quality score predicting the quality of user experience for the call given its technical parameters. Based on this process, one or more of the technical parameters of the call can be adapted to try to increase the quality experienced by the user.

Abstract: A method of encoding a video stream comprising: for each of a plurality of first image portions to be encoded in an outgoing video stream, selecting a preferred one of a set of potential encoding modes using a first process comprising an estimation of distortion of the first image portion and a measure of bit rate required to encode the first image portion for each of the first image portion's potential encoding modes; encoding each of the first image portions of the outgoing stream using the respective selected encoding mode; for each of a plurality of second image portions of a video stream, applying a second process comprising at least an estimation of distortion of the second image portion; and using an output of the second process resulting from the second image portions to bias the first process in said selection of the encoding modes for the first portions.

Abstract: Methods, transmitter, receiver and computer program product for transmitting or receiving data of a real-time communication event, the data being transmitted from the transmitter to a jitter buffer of the receiver. At least one processing parameter describing how data is to be processed for transmission from the transmitter to the jitter buffer in the real-time communication event is determined at the transmitter. Data is processed for transmission from the transmitter to the jitter buffer in accordance with the determined at least one processing parameter. Control information based on the determined at least one processing parameter is transmitted from the transmitter to the receiver, wherein the control information is for use by the receiver to control a state of the jitter buffer. The processed data is transmitted from the transmitter to the jitter buffer of the receiver in the real-time communication event.

Abstract: A method comprising: encoding a video image at each of a plurality of frames, including by using inter frame encoding to encode at least portions of some of the frames, thereby generating an encoded video stream; transmitting the encoded video stream over a lossy channel to be decoded at a receiver to produce decoded video; and performing a recovery operation to refresh the encoding of the video image, cutting off error propagation that has occurred in the decoded video due to an effect of inter prediction in presence of loss over said channel; wherein said recovery operation is triggered by a report fed back from the receiver indicative of loss; and wherein the recovery operation is performed over a plural number of frames, refreshing the encoding of different partial frame regions at different respective frames.

Abstract: Apparatus comprising an encoder configured to encode a video signal captured from a camera, and a low-light enhancement module configured to apply a low-light enhancement to the video signal. The low-light enhancement is performed in a colour space comprising two colour channels representing colour, and an achromatic channel representing light level. The enhancement comprises: detecting at least a first classification indicative of disturbance in the video signal due to capture in low light; and in response to detecting this classification, applying a low-light processing operation to at least one of the colour channels to reduce a number of bits incurred by colour in the encoding, such that an increased number of bits is spent on the achromatic channel when encoded by the encoder.

Abstract: Method, transmitter and computer program product for transmitting data of a real-time communication event from the transmitter to a jitter buffer of a receiver. The method comprises jointly determining (i) at least one processing parameter describing how data is to be processed for transmission from the transmitter to the jitter buffer, and (ii) jitter buffer control information for indicating to the receiver how to control a state of the jitter buffer. The jitter buffer control information is transmitted to the receiver. Data is processed for transmission from the transmitter to the jitter buffer in accordance with the determined at least one processing parameter. The processed data is transmitted from the transmitter to the jitter buffer of the receiver.

Abstract: Methods, transmitter, receiver and computer program product for transmitting or receiving data of a real-time communication event, the data being transmitted from the transmitter to a jitter buffer of the receiver. At least one processing parameter describing how data is to be processed for transmission from the transmitter to the jitter buffer in the real-time communication event is determined at the transmitter. Data is processed for transmission from the transmitter to the jitter buffer in accordance with the determined at least one processing parameter. Control information based on the determined at least one processing parameter is transmitted from the transmitter to the receiver, wherein the control information is for use by the receiver to control a state of the jitter buffer. The processed data is transmitted from the transmitter to the jitter buffer of the receiver in the real-time communication event.

Abstract: There is provided a method of controlling a rate at which content data is received at a receiver over a network, wherein the receiver has caused a first stream of real-time communication event data to be received at the receiver, and a second stream of content data to be received at the receiver, the method comprising steps of: dynamically measuring network conditions of the network based on the real-time communication event data; and limiting the rate at which the content data is received at the receiver based on the dynamically measured network conditions.

Abstract: A method of compressing video data, the method comprising: providing image data for each of a plurality of image portions; determining an index value for each of said image portions based on the respective image data; for a target image portion to be encoded, identifying a matching image portion having an index value within a search threshold of the index value of the target image portion; and generating difference data for the target image portion relative to the matching image portion, and including the difference data in an encoded video signal.

Abstract: A method comprising: encoding a video image at each of a plurality of frames, including by using inter frame encoding to encode at least portions of some of the frames, thereby generating an encoded video stream; transmitting the encoded video stream over a lossy channel to be decoded at a receiver to produce decoded video; and performing a recovery operation to refresh the encoding of the video image, cutting off error propagation that has occurred in the decoded video due to an effect of inter prediction in presence of loss over said channel; wherein the recovery operation is triggered by a report fed back from the receiver indicative of loss; and wherein the recovery operation is performed over a plural number of frames, refreshing the encoding of different partial frame regions at different respective frames.

Abstract: Method, transmitter and computer program product for transmitting data of a real-time communication event from the transmitter to a jitter buffer of a receiver. Jitter buffer state information is received at the transmitter from the receiver, the jitter buffer state information indicating a state of the jitter buffer. At least one processing parameter is controlled based on the received jitter buffer state information, the at least one processing parameter describing how data is to be processed for transmission from the transmitter to the jitter buffer in the real-time communication event. Data is processed for transmission from the transmitter to the jitter buffer in accordance with the determined at least one processing parameter. The processed data is transmitted from the transmitter to the jitter buffer of the receiver in the real-time communication event.

Abstract: A method comprising: for each target image portion to be encoded in a frame, selecting one of a set of encoding modes by optimizing a function comprising an estimate of distortion for the target image portion and a measure of bit rate required to encode the target image portion, encoding the target image portion into the encoded video stream using the selected mode. The encoded video stream is transmitted over a lossy channel. An error propagation distortion map is maintained, which comprises a plurality of error propagation distortion values mapping to respective frame partitions, the error propagation distortion values being based on previous encoding mode selections. The estimate of distortion used to select the encoding mode for each of the target image portions is based on a corresponding portion from the error propagation distortion map, and that corresponding portion is constrained to being co-located with the target image portion.

Abstract: A method of transmitting video data from a transmitter to a receiver, the method comprising: receiving data values of a video signal at a higher resolution; at the transmitter, combining groups of the data values into one or more first units of a first lower-resolution arrangement; encoding and transmitting the first lower-resolution arrangement to the receiver; at the transmitter, combining groups of the data values into one or more second units of a second lower-resolution arrangement, wherein the second units are offset from the first units by a fractional shift such that each second unit partially overlaps with at least one first unit; encoding and transmitting the second lower-resolution arrangement to the receiver; and transmitting an indication of said shift to the receiver; and at the receiver, combining the first and second lower-resolution arrangements based on the indication so as to reconstruct an image of at least a higher resolution than that of the first and second lower-resolution arrangements

Abstract: Correction data units for data packets of a data stream are generated. A correction data unit is based on a set of the data packets of the stream. The stream is transmitted over a lossy communication channel. A performance measure to be optimized is selected, which relates to the recovery of lost data packets of the stream. A coding requirement is determined. For the generation of the correction data units, it is determined, within the constraints of the coding requirement and based on previously generated correction data units, which of the data packets in the stream to include in the set on which the generation of the correction data unit is to be based to thereby optimize the selected performance measure. A generated correction data unit is generated based on a respective set of the data packets of the stream. The generated correction data units are included in the stream.

Abstract: A method and a system for estimating a road gradient ? by using a sensor fusion: Detect whether at least one dynamic process is affecting the vehicle. Estimate gradient ? by means of the sensor fusion by joint weighting of at least two input signals to the sensor fusion. The at least two input signals include a signal based on an accelerometer and an input signal based on at least one force equation. At least one of the input signals and/or at least one weighting parameter for the sensor fusion are determined on the basis of detecting whether the at least one dynamic process is affecting the vehicle.