Appendix – Code for implementation of the Audio Codec

All the code in this report is the part of the dissertation work (DCS 475 Dissertation) for the MSc in Digital Signal Processing and Intelligent Systems, School of Computing and Communication, Lancaster University, England.

A-1 Differential Feed-Forward CODEC

Figure A.1.1 Differential Feed-Forward Encoder

Figure A.1.2 Differential Feed-Forward Decoder

The above shown block diagram are the encoder and the decoder of the differential feed-forward coded and the implementation of the differential feed-forward codec is the m-file, as included above.

A-2 Differential Feed-Back CODEC

Figure A.2.1 Differential Feedback Encoder ^.

Figure A.2.2 Differential Feedback Decoder.

The above shown block diagram are the encoder and the decoder of the differential feed-back coded and the implementation of the differential feed-back codec is the m-file, as included above.

A-3 Adaptive Differential Feed-Back CODEC

Figure A.3.1 Multi-Channel Adaptive Differential Encoder.

Figure A.4.2 Multi-channels Adaptive Differential Decoder.

The above shown block diagram are the encoder and the decoder of the adaptive differential feed-back coded and the implementation of the adaptive differential feed-back codec is the m-file, as included above.

A-4 Functions used to implement the audio CODEC

A-4.1 Implementation of the Huffman Encoding.

A-4.2 Implementation of the IDCT with windowing.

A-4.3 Implementation of the adaptation for quantisation.

A-4.4 Implementation of the inter-channel redundancy removal.

A-4.5 Implementation of the Overlap-and-add technique.