Abstract: A method of filtering a packet data stream as transmitted in a digital audiovisual transmission system characterized in that transport packet data is filtered at a first stage by a digital filter (42) according to the characteristics of the transport packet header, selected filtered data being then passed directly to a memory element (44) within the receiver/decoder. In a second aspect, the method comprises filtering a packet data stream characterized in that transport packet data is filtered at a first stage by a first digital filter (42) according to the characteristics of the transport packet header, selected filtered data from the payload corresponding to a continuous flux of data then being passed to a second digital filter (45) for a second stage of filtering.

Abstract: A method of filtering a packet data stream as transmitted in a digital audiovisual transmission system characterized in that transport packet data is filtered at a first stage by a digital filter according to the characteristics of the transport packet header, selected filtered data being then passed directly to a memory element within the receiver/decoder. In a second aspect, the method comprises filtering a packet data stream characterized in that transport packet data is filtered at a first stage by a first digital filter according to the characteristics of the transport packet header, selected filtered data from the paload corresponding to a continuous flux of data then being passed to a second digital filter for a second stage of filtering.

Abstract: A method of filtering a packet data stream as transmitted in a digital audiovisual transmission system characterized in that transport packet data is filtered at a first stage by a digital filter (42) according to the characteristics of the transport packet header, selected filtered data being then passed directly to a memory element (44) within the receiver/decoder. In a second aspect, the method comprises filtering a packet data stream characterized in that transport packet data is filtered at a first stage by a first digital filter (42) according to the characteristics of the transport packet header, selected filtered data from the payload corresponding to a continuous flux of data then being passed to a second digital filter (45) for a second stage of filtering.

Abstract: A device for coding a sequence of pictures divided into successive groups of N pictures arranged in picture blocks or macroblocks and including at least one channel for quantization and variable length coding of the blocks or macroblocks, and a bitrate control sub-assembly. The sub-assembly includes a buffer memory and a device for modifying the quantization step used in quantization of the blocks or macroblocks. The buffer memory and the device for modifying the quantization step are connected in series.

Abstract: Method and corresponding circuit for estimating motion between pictures composed of interlaced fields. Conventionally, such a circuit comprises a channel for searching for the optimum frame vector, which channel is autonomous with respect to that for searching for the optimum field vectors. In accordance with the invention, the channel for searching for the optimum field vectors is unchanged, but for searching for the optimum frame vector the channel comprises two branches which are no longer autonomous but are arranged at the respective output of each sub-stage for searching for the field vector of the channel with a view to determining an approximation of the motion vector which is sufficient for the searched estimation.