Supervisors: Stefan Sandström (Axis), Mats Cedervall (IT/LTH)
Recently, algorithms that can compress audio-signals like music without perceptible loss up to ratios around 1:12 have emerged. This makes it possible and very feasible to store large amounts of music on comparatively small amounts of storage media. It also makes it possible to implement realtime playback of music over low-bandwidth computer networks. The goal of the thesis was to demonstrate this using dedicated, embedded hardware that performs the network accesses and audio decompression without the aid of an external computer. The chosen algorithm is MPEG-1/Layer-3, and it has been implemented using C and assembler on a Texas TMS320C31 DSP. The network access is done using an Axis NPS570 printerserver, using Axis embedded ethernet processor ETRAX. The unit accepts MPEG compressed audio over a network using the TCP/IP protocol suite, and feeds it into the DSP for decompression and playback.
Copyright 1997, Björn Wesén. All rights reserved.
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