Audio decoding method and associated apparatus

摘要

An audio decoding method is provided. In the audio decoding method, a synchronization word and a corresponding packet header are inserted at the beginning of each packet data. A position of the packet data is confirmed according to the synchronization word, and the packet data is then decoded according to information in the packet header. Accordingly, when an error occurs during the decoding process, the decoding process skips to a next packet data for decoding to avoid noise. In addition, a packet header can be directly accessed in the situation of a fast-forward operation to obtain decoding information of the packet data to perform audio decoding.

主权项

1. An audio decoding method, the method comprising:
dividing, in an audio decoding apparatus of a windows media audio (WMA) file playback apparatus, an audio data into a header part and a data part; determining a first packet data from the data part according to the header part, wherein the first packet data is a part of the data part and a data size of the first packet is smaller than a data size of the data part; generating a first packet header corresponding to the first packet data according to the header part, a data size of the first packet header is smaller than a data size of the header part, and the first packet header is different from the header part; inserting a predefined synchronization word and the first packet header at a beginning of the first packet data to generate a first intermediate data; detecting the synchronization word in the first intermediate data to confirm a position of the first packet data, and decoding the first packet data according to the first packet header; detecting whether a fast-forward command is received during decoding process, and generating a fast-forward message when the fast-forward command is received; determining a third packet data from the data part according to the information in the header part and the fast-forward message; generating a third packet header corresponding to the third packet data according to the information in the header part; generating a third intermediate data according to the synchronization word, the third packet header and the third packet data; and detecting the synchronization word in the third intermediate data, and decoding the third packet data according to the third packet header, wherein steps subsequent to receiving, and executing, the fast-forward command are all performed without re-reading the header part.