Abstract: When a producer processing unit, such as a video decoder, of a media processing system is producing a data output for use by a consumer processing unit, such as a display processor, the producer processing unit also generates metadata for the data output that it is producing and provides that metadata for use by the consumer processing unit. The consumer processing unit then uses the metadata provided by the producer processing unit when processing the data output to which the metadata relates.

Abstract: A method for adapting a trained neural network is provided. Input data is input to the trained neural network and a plurality of filters are applied to generate a plurality of channels of activation data. Differences between corresponding activation values in the plurality of channels of activation data are calculated and an order of the plurality of channels is determined based on the calculated differences. The neural network is adapted so that it will output channels of activation data in the determined order. The ordering of the channels of activation data is subsequently used to compress activation data values by taking advantage of a correlation between activation data values in adjacent channels.

Abstract: When encoding a block of data elements in an array of data elements, the data values for data elements in the block are represented and stored in a data packet as truncated data values using a subset of one or more most significant bits of the respective bit sequences for the data values of the data elements. A rounding mode is selected from a plurality of available rounding modes that can be applied when decoding the block of data elements and an indication of the selected rounding mode is provided along with the encoded data packet. The rounding mode is associated with one or more rounding bit sequence(s) that can then be applied to the truncated data values when decoding the data packet to obtain decoded data values for the data elements in the block.

Abstract: Disclosed herein is a method of encoding an array of data elements comprising transforming the array from the spatial to the frequency domain, representing the frequency domain coefficients as a plurality of bit plane arrays, and encoding the set of frequency domain coefficients as a data packet having a fixed size by encoding the bit plane arrays in a bit plane sequence working from the bit plane array representing the most significant bit downwards until the data packet is full. Each bit plane array is encoded by recursively subdividing the bit plane array into respective sections and subsections down to the individual coefficients and including in the data packet, so long as there is available space, data indicating the locations of any (sub)sections in that bit plane array that for the first time in the bit plane sequence contain one or more coefficient(s) having a non-zero bit value.

Abstract: A producer processing unit of a data processing system that is producing a stream of data for use by one or more consumer processing units of the data processing system maintains a record that is accessible to the consumer processing units of a position in the data stream for which it has written data to memory. The consumer processing units then control their reading of the data stream from the memory in accordance with the write position record maintained by the producer processing unit.

Abstract: A method for adapting a trained neural network is provided. Input data is input to the trained neural network and a plurality of filters are applied to generate a plurality of channels of activation data. Differences between corresponding activation values in the plurality of channels of activation data are calculated and an order of the plurality of channels is determined based on the calculated differences. The neural network is adapted so that it will output channels of activation data in the determined order. The ordering of the channels of activation data is subsequently used to compress activation data values by taking advantage of a correlation between activation data values in adjacent channels.

Abstract: When encoding a block of data elements in an array of data elements, the data values for data elements in the block are represented and stored in a data packet as truncated data values using a subset of one or more most significant bits of the respective bit sequences for the data values of the data elements. A rounding mode is selected from a plurality of available rounding modes that can be applied when decoding the block of data elements and an indication of the selected rounding mode is provided along with the encoded data packet. The rounding mode is associated with one or more rounding bit sequence(s) that can then be applied to the truncated data values when decoding the data packet to obtain decoded data values for the data elements in the block.

Abstract: An apparatus for encoding frames of a sequence of source frames of video image data to be encoded. The apparatus includes encoding circuitry configured to encode the source frames using reference frames. The apparatus also includes monitoring circuitry configured to, when the encoding circuitry is encoding a source frame using one or more reference frames, monitor the memory bandwidth being used when using the one or more reference frames when encoding the source frame. The apparatus further includes encoding circuitry that is operable to, in response to the monitored memory bandwidth being greater than a threshold, to control the encoding circuitry to encode a subsequent part of the source frame using a modified video encoding process to restrict the memory bandwidth usage when using one or more reference frames when encoding a subsequent part of a source frame.

Abstract: A data processing system is provided including a processing element and a storage. The storage stores code portions that, when executed by the processing element, cause the data processing system to obtain a plurality of variable length codes. Each variable length code has a first portion of a variable length and a second portion. The variable length codes are separated into first portions of the variable length codes and second portions of the variable length codes. The data processing system forms a processed stream in chunks using a set of control rules so that, for each chunk of the processed stream containing data from the first portions of the variable length codes, the data from the first portions forms a sub-stream within the chunk of the processed stream that has a size that is determined in accordance with the control rules.

Abstract: When encoding an array of data elements, or a stream of such arrays, using an encoder comprising encoding circuitry operable to encode the array(s) of data elements as a plurality of independent segments, wherein each independent segment can be decoded independently; a header is generated for output with an encoded data stream including the plurality of independent segments wherein the header contains information indicative of the location of each of the plurality of independent segments within the encoded data stream. When an encoded data stream associated with such a header is to be decoded, a decoder may thus read the header to identify the location of the independent segment within the data stream and then read and decode the identified segments from the identified location(s) in the data stream.

Abstract: When encoding an array of data elements of a stream of arrays of data elements, a set of sample adaptive offset options to be used for encoding the array are selecting on the basis of a distortion value that is determined for a particular set of sample adaptive offset options. The distortion value is determined by generating one or more filtered reconstructed source blocks by applying a sample adaptive offset filter in accordance with the particular set of sample adaptive offset options to one or more reconstructed source blocks corresponding to a source block, and by then determining a distortion value for the particular set of sample adaptive offset options by comparing the one or more filtered reconstructed source blocks with the source block. When the particular set of sample adaptive offset options comprises an edge offset type, the distortion value is determined using a set of error values comprising fewer data elements than the source block of data elements.

Abstract: A video processing system includes a host processor, a video encoder and a memory. The host processor sends a configuration message to the video encoder that indicates to the video encoder how to encode a video frame and that includes information indicating the location of encoding configuration data that is stored in the memory. The video encoder receives the configuration message, uses the location indicating information to read the encoding configuration data from the memory, and encodes the video frame in accordance with the encoding configuration data read from the memory.

Abstract: A set of encoding options to use when encoding an array of data elements is selected based on a bit count value and a distortion value for that set of encoding options. The distortion value is determined from a set of error values that represents the difference between a set of frequency domain coefficients and a set of de-quantised coefficients. The set of frequency domain coefficients are generated by applying only a subset of row transformations or only a subset of column transformations. A set of quantised coefficients are generated by quantising only a subset of the set of frequency domain coefficients. This arrangement provides a more efficient way of selecting encoding options, but without a detrimental reduction in the efficacy of the selection process.

Abstract: When a producer processing unit, such as a video decoder, of a media processing system is producing a data output for use by a consumer processing unit, such as a display processor, the producer processing unit also generates metadata for the data output that it is producing and provides that metadata for use by the consumer processing unit. The consumer processing unit then uses the metadata provided by the producer processing unit when processing the data output to which the metadata relates.

Abstract: When encoding an array of data elements of a stream of arrays of data elements, a set of sample adaptive offset options to be used for encoding the array are selecting on the basis of a distortion value that is determined for a particular set of sample adaptive offset options. The distortion value is determined by generating one or more filtered reconstructed source blocks by applying a sample adaptive offset filter in accordance with the particular set of sample adaptive offset options to one or more reconstructed source blocks corresponding to a source block, and by then determining a distortion value for the particular set of sample adaptive offset options by comparing the one or more filtered reconstructed source blocks with the source block. When the particular set of sample adaptive offset options comprises an edge offset type, the distortion value is determined using a set of error values comprising fewer data elements than the source block of data elements.

Abstract: When encoding an array of data elements, or a stream of such arrays, using an encoder comprising encoding circuitry operable to encode the array(s) of data elements as a plurality of independent segments, wherein each independent segment can be decoded independently; a header is generated for output with an encoded data stream including the plurality of independent segments wherein the header contains information indicative of the location of each of the plurality of independent segments within the encoded data stream. When an encoded data stream associated with such a header is to be decoded, a decoder may thus read the header to identify the location of the independent segment within the data stream and then read and decode the identified segments from the identified location(s) in the data stream.

Abstract: When encoding an array of quantized frequency domain coefficients for the chrominance data values for a block of data elements being encoded, it is determined whether the encoding of the frequency domain coefficients for the luminance data for the block being considered was indicated as to be omitted. If so, it is then determined whether the non-zero coefficients in the array of quantized chrominance data value frequency domain coefficients for the block are few in number and/or small in size. If the number and/or size of the non-zero quantized chrominance value frequency domain coefficients is determined to be sufficiently few and/or small, then the encoding of the quantized frequency domain coefficients for the chrominance data for the block is omitted.

Abstract: A producer processing unit of a data processing system that is producing a stream of data for use by one or more consumer processing units of the data processing system maintains a record that is accessible to the consumer processing units of a position in the data stream for which it has written data to memory. The consumer processing units then control their reading of the data stream from the memory in accordance with the write position record maintained by the producer processing unit.

Abstract: When encoding an array of quantized frequency domain coefficients for the chrominance data values for a block of data elements being encoded, it is determined whether the encoding of the frequency domain coefficients for the luminance data for the block being considered was indicated as to be omitted. If so, it is then determined whether the non-zero coefficients in the array of quantized chrominance data value frequency domain coefficients for the block are few in number and/or small in size. If the number and/or size of the non-zero quantized chrominance value frequency domain coefficients is determined to be sufficiently few and/or small, then the encoding of the quantized frequency domain coefficients for the chrominance data for the block is omitted.

Abstract: An apparatus for encoding frames of a sequence of source frames of video image data to be encoded. The apparatus includes encoding circuitry configured to encode the source frames using reference frames. The apparatus also includes monitoring circuitry configured to, when the encoding circuitry is encoding a source frame using one or more reference frames, monitor the memory bandwidth being used when using the one or more reference frames when encoding the source frame. The apparatus further includes encoding circuitry that is operable to, in response to the monitored memory bandwidth being greater than a threshold, to control the encoding circuitry to encode a subsequent part of the source frame using a modified video encoding process to restrict the memory bandwidth usage when using one or more reference frames when encoding a subsequent part of a source frame.