VARIABLE LENGTH ENCODING AND DECODING METHOD

摘要

The invention discloses a new variable length encoding and decoding method that is directed to resolve the VLC sequence number errors that tend to happen in prior arts. In the invention, at least two types of VLCs are used alternatively for variable length encoding when performing the signal source encoding, and the bitstreams are decoded by different VLCs alternatively according to the encoding arrangement rules when performing the signal source decoding. When the sync bit of one of the VLCs is wrong, if decoding is directly performed without correcting errors, the rule of alternative VLCs will be destroyed. At this time, posterior probability can be used to judge the maximum error probability, and the maximum posterior probability can be outputted as the decoding result, so the rule of alternative VLCs will be kept. In the invention, the inserting or deleting errors will not happen, and every VLC sequence number will not change.