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G.711 Speech Coder TMS320C5000 DSP Code

Description: ITU G.711 coding implements the digitisation process on telephone signals used within digital telephone exchanges so representing standard telephone quality speech. The sample rate is 8kHz with the signal bandlimited to the range 300Hz to 3.4kHz. The compression by Pulse Code Modulation (PCM) is to a data rate of 64kb/s. Each input linear sample is assigned an 8-bit PCM code depending on its amplitude. Two coding methods are implemented that are similar but not compatible: A-law, as used in European telephone networks, and µ-law, as used in American and Japanese telephony circuits. G.711 is also a standard for video conferencing audio, and is often used for speech storage. The coding process can pass data modem signals up to V.34 ie 33.6kb/s.
         In the Algotron implementation, encoder and decoder are operated as separate items. With the assembler interface, each has an individual per-sample/PCM-code subroutine call. No permanent memory is used. A C-callable wrapper file can also be provided, allowing individual channels to be called from C for processing of multiple sample/code blocks. A comprehensive user's guide is provided with the code.

Processor Load:

- #figures for assembler interfaces with TMS320C54x operation

Availability: NOW - sale is under licence - integration support offered