README
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2GSM 06.10 13 kbit/s RPE/LTP speech compression available
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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.
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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.
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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).
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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.
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28Jutta Degener (then jutta@cs.tu-berlin.de, nowadays jutta@pobox.com)
29Carsten Bormann (then cabo@cs.tu-berlin.de, nowadays cabo@tzi.org)
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31Communications and Operating Systems Research Group, TU Berlin
32Fax: +49.30.31425156, Phone: +49.30.31424315
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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.
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README.version