METHOD AND DEVICE FOR DECODING CODED DIGITAL VIDEO SIGNALS

Conventional MPEG decoders require about 16 Mbits of external memory to contain the input buffer, the two usual reference frames, and the B-information. As proposed earlier, about 2,8 Mbit in memory capacity can be saved by omitting the storage of B-information. The system, provides a further exchange between memory capacity and internal processing, to effect MPEG decoding, with only one reference frame stored in memory. All B and P information required for the reconstruction of display information which cannot directly be retrieved from memory is decoded instantaneously. Three decoding sub-steps are provided, a first decoding sub-step for the macroblock parameters, a second decoding sub-step for the picture elements according to a decoding-on-the-fly principle, and a third decoding sub-step for updating of the earlier reference frame after decoding of a later reference frame.