/* * Copyright 1992 by Jutta Degener and Carsten Bormann, Technische * Universitaet Berlin.  See the accompanying file "COPYRIGHT" for * details.  THERE IS ABSOLUTELY NO WARRANTY FOR THIS SOFTWARE. */ GSM 06.10 13 kbit/s RPE/LTP speech compression available--------------------------------------------------------The Communications and Operating Systems Research Group (KBS) at theTechnische Universitaet Berlin is currently working on a set ofUNIX-based tools for computer-mediated telecooperation that will bemade freely available.As part of this effort we are publishing an implementation of theEuropean GSM 06.10 provisional standard for full-rate speechtranscoding, prI-ETS 300 036, which uses RPE/LTP (residual pulseexcitation/long term prediction) coding at 13 kbit/s.GSM 06.10 compresses frames of 160 13-bit samples (8 kHz samplingrate, i.e. a frame rate of 50 Hz) into 260 bits; for compatibilitywith typical UNIX applications, our implementation turns frames of 16016-bit linear samples into 33-byte frames (1650 Bytes/s).The quality of the algorithm is good enough for reliable speakerrecognition; even music often survives transcoding in recognizable form (given the bandwidth limitations of 8 kHz sampling rate).The interfaces offered are a front end modelled after compress(1), anda library API.  Compression and decompression run faster than realtimeon most SPARCstations.  The implementation has been verified against theETSI standard test patterns.Jutta Degener (jutta@cs.tu-berlin.de)Carsten Bormann (cabo@cs.tu-berlin.de)Communications and Operating Systems Research Group, TU BerlinFax: +49.30.31425156, Phone: +49.30.31424315