Research On Audio Compression Arithmetic Based On Voyage Data Recorder

Voyage Data Recorder is an equipment which can record ship navigation status and manipulation information and take an important role on navigation safety at sea and accident analysis. As the main data source of Voyage Data Recorder, audio data has a large scale. Therefore audio compression system has become a major part of Voyage Data Recorder. Based on it, the thesis introduces the study and design of the audio compression system which is the kernel technical part of Voyage Data Recorder.First of all, the thesis introduces the development history, system structure and key technique, and also tells the development history and general situation inside and outside. Second, the thesis introduces the fundamental principle of VxWorks which is the system platform of Voyage Data Recorder, and also introduces some developing experience of VxWorks system. Afterwards, the thesis introduces some study on fundamental principle of audio compression from the view of human hearing system and perceptual model, and also introduces some common audio coding technique: subband coding, transform coding and Huffman coding. Combined with system structure character, study out the audio compression system case of Voyage Data Recorder system. This thesis emphasis on the work of MPEG-â…  Layer â…¡ arithmetic standard, and bat around the whole flow of the arithmetic, including analysis subband filter bank, psychoacoustic model, uantization and coding, formatting. At last, in allusion to two modules of subband filter bank and psychoacoustic model which have more calculation, this thesis introduces a method of improvement and optimization. Through running the system, audio compression system reach the requirement of the Voyage Data Recorder system.This thesis is background with Voyage Data Recorder R&D, and introduces the particular research about audio compression principle. It can be useful for reference for national craft brother of audio compression.