Abstract: A video decoder configured to decode an encoded video bitstream comprises a first parsing unit and a second parsing unit, each configured to independently parse the encoded video bitstream to derive parsing state information therefrom on which subsequent parsing of the encoded video bitstream at least partially depends and to identify macroblock information for decoding. The encoded video bitstream comprises frame header information defining a sequence of frames and each frame is composed of macroblocks represented by macroblock information. A control unit of the video encoder allocates each frame of macroblock information to one of the two parsing units to parse. The two parsing units are both configured to parse frame header information to thereby each derive parsing state information for the encoded video bitstream, and the two parsing unit are each configured to parse macroblock information allocated to them, skipping macroblock information allocated to the other parsing unit.

Abstract: When encoding an array of data elements of a stream of arrays of data elements, a number of bits used in the output bitstream to encode a previous array of data elements in the stream of arrays of data elements is estimated based on an amount of intermediate data generated for that previous array of data elements by the encoding process. A value of an encoding parameter to use when encoding the array of data elements being encoded is then selected based on the estimated number of bits used in the output bitstream to encode the previous array of data elements and a target output bit rate for the output bitstream produced when encoding the stream of arrays of data elements.

Abstract: An apparatus for decoding a sequence of frames of encoded video data includes parsing circuitry configured to parse the encoded video image data for a frame to derive encoding information for each block of the frame. The apparatus also includes feedback circuitry configured to feed back, to the parsing circuitry, encoding information for a frame for use when parsing the encoded video image data of the next frame. The encoding information includes an encoding indicator for each block. When the encoding indicators were enabled when encoding the blocks of the frame, the encoding indicator fed back for a block is the encoding indicator that was used to encode that block. When the encoding indicators for the blocks of the frame were disabled when encoding the video image data for the frame, the encoding indicator fed back for a block is an encoding indicator derived from a previous frame.

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: 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, 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: 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 data elements of a stream of arrays of data elements, a number of bits used in the output bitstream to encode a previous array of data elements in the stream of arrays of data elements is estimated based on an amount of intermediate data generated for that previous array of data elements by the encoding process. A value of an encoding parameter to use when encoding the array of data elements being encoded is then selected based on the estimated number of bits used in the output bitstream to encode the previous array of data elements and a target output bit rate for the output bitstream produced when encoding the stream of arrays of data elements.

Abstract: A video decoder configured to decode an encoded video bitstream comprises a first parsing unit and a second parsing unit, each configured to independently parse the encoded video bitstream to derive parsing state information therefrom on which subsequent parsing of the encoded video bitstream at least partially depends and to identify macroblock information for decoding. The encoded video bitstream comprises frame header information defining a sequence of frames and each frame is composed of macroblocks represented by macroblock information. A control unit of the video encoder allocates each frame of macroblock information to one of the two parsing units to parse. The two parsing units are both configured to parse frame header information to thereby each derive parsing state information for the encoded video bitstream, and the two parsing unit are each configured to parse macroblock information allocated to them, skipping macroblock information allocated to the other parsing unit.

Abstract: A video decoder configured to decode an encoded video bitstream comprises a first parsing unit and a second parsing unit, each configured to independently parse the encoded video bitstream to derive parsing state information therefrom on which subsequent parsing of the encoded video bitstream at least partially depends and to identify macroblock information for decoding. The encoded video bitstream comprises frame header information defining a sequence of frames and each frame is composed of macroblocks represented by macroblock information. A control unit of the video encoder allocates each frame of macroblock information to one of the two parsing units to parse. The two parsing units are both configured to parse frame header information to thereby each derive parsing state information for the encoded video bitstream, and the two parsing unit are each configured to parse macroblock information allocated to them, skipping macroblock information allocated to the other parsing unit.

Abstract: A method of operating a data processing system is disclosed for a data processing system that comprises a display and a display controller operable to provide to the display data in respect of output surfaces to be displayed. The method comprises, when an output surface is to be displayed, the display controller providing to the display data in respect of the output surface in the form of image data and image modification data, and the display using the image data and the image modification data when producing an output surface for display.

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 video decoding apparatus for decoding an encoded video bitstream having a sequence of video pictures, wherein at least one video picture is encoded in a plurality of slices, wherein each slice comprises a sequence of raster scan order blocks which can be decoded independently of another slice.

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 video encoder and method of video encoding are provided. At an encoding stage a selected degree of quantization is applied to the encoding of macroblocks of the input video sequence and quantized part-encoded macroblocks are generated. Quantization circuitry in the encoding stage is configured to select the selected degree of quantization for each macroblock in a current slice in dependence on a complexity estimate indicative of the expected entropy encoding complexity of a predetermined set of the quantized part-encoded macroblocks defined for that macroblock.

Abstract: An apparatus for decoding a sequence of frames of encoded video data includes parsing circuitry configured to parse the encoded video image data for a frame to derive encoding information for each block of the frame. The apparatus also includes feedback circuitry configured to feed back, to the parsing circuitry, encoding information for a frame for use when parsing the encoded video image data of the next frame. The encoding information includes an encoding indicator for each block. When the encoding indicators were enabled when encoding the blocks of the frame, the encoding indicator fed back for a block is the encoding indicator that was used to encode that block. When the encoding indicators for the blocks of the frame were disabled when encoding the video image data for the frame, the encoding indicator fed back for a block is an encoding indicator derived from a previous frame.

Abstract: A data processing apparatus and method are provided for performing rearrangement operations. The data processing apparatus has a register data store with a plurality of registers, each register storing a plurality of data elements. Processing circuitry is responsive to control signals to perform processing operations on the data elements.

Abstract: A data processing apparatus and method are provided for performing a transform between spatial and frequency domains when processing video data. The data processing apparatus comprises transform circuitry configured to receive N input values and to perform a sequence of operations to generate N output values representing the transform of the N input values between the spatial and frequency domains. In doing this, the transform circuitry employs a base circuitry that is configured to receive M internal input values generated by the transform circuitry, where M is greater than or equal to 4, and to perform a base operation equivalent to matrix multiplication of the M internal input values by a Hankel matrix, which is a square matrix with constant skew diagonals, where each element of the array identifies a coefficient, performance of the base operation generating M internal output values for returning to the transform circuitry.

Abstract: A data processing apparatus is provided, comprising plural processing units configured to execute plural processes, a storage unit configured to store data required for the plural processes; and a protection unit configured to control access by the plural processes to the storage unit. The protection unit is configured to define an allocated access region of the storage unit for each process of the plural processes, wherein the protection unit is configured to deny access for each the process outside the allocated access region and wherein allocated access regions are defined to be non-overlapping. The protection unit is configured to define each allocated access region as a contiguous portion of the storage unit between a lower region limit and an upper region limit, and the protection unit is configured such that when the lower region limit is modified the lower region limit cannot be decreased and such that when the upper region limit is modified the upper region limit cannot be decreased.

Abstract: A video encoder and method of video encoding are provided. At an encoding stage a selected degree of quantization is applied to the encoding of macroblocks of the input video sequence and quantized part-encoded macroblocks are generated. Quantization circuitry in the encoding stage is configured to select the selected degree of quantization for each macroblock in a current slice in dependence on a complexity estimate indicative of the expected entropy encoding complexity of a predetermined set of the quantized part-encoded macroblocks defined for that macroblock.