1 2GSM 06.10 13 kbit/s RPE/LTP speech compression available 3-------------------------------------------------------- 4 5The Communications and Operating Systems Research Group (KBS) at the 6Technische Universitaet Berlin is currently working on a set of 7UNIX-based tools for computer-mediated telecooperation that will be 8made freely available. 9 10As part of this effort we are publishing an implementation of the 11European GSM 06.10 provisional standard for full-rate speech 12transcoding, prI-ETS 300 036, which uses RPE/LTP (residual pulse 13excitation/long term prediction) coding at 13 kbit/s. 14 15GSM 06.10 compresses frames of 160 13-bit samples (8 kHz sampling 16rate, i.e. a frame rate of 50 Hz) into 260 bits; for compatibility 17with typical UNIX applications, our implementation turns frames of 160 1816-bit linear samples into 33-byte frames (1650 Bytes/s). 19The quality of the algorithm is good enough for reliable speaker 20recognition; even music often survives transcoding in recognizable 21form (given the bandwidth limitations of 8 kHz sampling rate). 22 23The interfaces offered are a front end modelled after compress(1), and 24a library API. Compression and decompression run faster than realtime 25on most SPARCstations. The implementation has been verified against the 26ETSI standard test patterns. 27 28Jutta Degener (then jutta@cs.tu-berlin.de, nowadays jutta@pobox.com) 29Carsten Bormann (then cabo@cs.tu-berlin.de, nowadays cabo@tzi.org) 30 31Communications and Operating Systems Research Group, TU Berlin 32Fax: +49.30.31425156, Phone: +49.30.31424315 33 34-- 35Copyright 1992 by Jutta Degener and Carsten Bormann, Technische 36Universitaet Berlin. See the accompanying file "COPYRIGHT" for 37details. THERE IS ABSOLUTELY NO WARRANTY FOR THIS SOFTWARE. 38