An encoder for coding a digital signal comprises an encoder input for receiving the digital signal; a first data processor, having an input which is coupled to the encoder input, for generating a first coded digital signal at a first output of the first data processor; a first reduction device coupled to the encoder input, for reducing the received digital signal; a second data processor, having an input which is coupled to the first reduction device, for generating a second coded digital signal at a first output of the second data processor; a first encoder memory having an input which is coupled to a second output of the first data processor, and having an output which is coupled to the input of the first data processor; a second encoder memory having an input which is coupled to a second output of the second data processor, and having an output which is coupled to the input of the second data processor; and a first encoder prediction device having a first side which is coupled to the second output of the second data processor, and a second side which is coupled to both the input of the first encoder memory and the input of the first data processor. A decoder for decoding a digital signal which is encoded as described above, comprises a first data reprocessing device for processing a coded digital signal; and a decoder memory having an input which is coupled to an output of the first data reprocessing device.

This encoding arrangement has an input (12) for receiving a sequence of samples to be encoded, an output for supplying encoded samples, processing circuits, more specifically: a differential circuit (20) for producing differential samples between the samples to be encoded and prediction samples, a prediction circuit (22) to produce prediction samples from the encoded samples. It is characterized in that the processing circuits are separated into encoding units (E1, E2, E3 and E4) for each effecting a processing operation on each sample to be encoded and that an interleaving member (60) is provided to convert the sequence of samples to be encoded into a sequence of interleaved samples so as to ensure that all the processing operations to be effected on a sample are indeed effected.

A system for transmitting video pictures includes a hybrid encoder which encodes the incoming data of a video picture in blocks. Preferably, at the receiver end a hybrid decoder cancels the encoding steps of the hybrid encoder. The incoming blocks of a video picture are transformed inter alia by a transform unit (T) and quantized by a quantizer (Q). In order to adapt the system to transmission bit rates of between 64 kbit/s and 2 Mbit/s in an optimum manner, a structuring unit (SE) is provided which combines a plurality of blocks, which represent a coherent section of a video picture, to one macro-block. It assigns a macro-attribute to each macro-block from which attribute it can be derived which properties are identical for all sub-blocks of the macro-blocks and which are not. Such properties are, for example, records about the motion vector of each sub-block, which vector may be the same, for example, for all sub-blocks. When using a separate macro-attribute (NON), there is no property which can be considered to be the same for all sub-blocks of a macro-block, but the properties are assigned to each sub-block proper. If required, the macro-blocks themselves are again treated as sub-blocks, i.e. they are combined to still larger units. When transmitting stationary pictures, a very effective encoding is the result.

A motion compensated prediction interframe coding system which includes a first checking portion for judging whether a motion compensation of a coding block is effective and outputting a motion compensation control signal representing the result of the judgement, a storage portion for storing motion vectors of the coding block and adjacent blocks and the motion compensation control signal, a second checking portion for comparing the motion vector of the coding block, of which the motion compensation should be effected, with each of the motion vectors of the adjacent blocks, of which the motion compensation should be effected, and judging that the intra-loop filtering processing to be performed after the motion compensation is ineffective if the number of the adjacent blocks, of which the motion vectors are identical with that of the coding block, is equal to or more than a predetermined number and that the filtering processing performed after the motion compensation is effective in another case, a motion-compensated brightness calculating portion for calculating motion-compensated brightness of pixels of the blocks, of which the motion compensation is effected, and a predictive brightness calculating portion for calculating predictive brightness of the pixels of the blocks by performing the filtering processing of the motion-compensated brightness of the pixels only if the filtering processing is effective. Thereby, the amount of the generated prediction error signals are reduced, and the picture quality is improved.

A video coding technique having motion compensation for bi-directional predicted frames (B-frames) and predicted frames (P-frames). The video coding technique involves a single-loop prediction-based base layer which includes base layer B- and/or P-frames that are generated from "extended" or "enhanced" base layer reference frames during base layer coding.