| |
| GSM 06.10 13 kbit/s RPE/LTP speech compression available |
| -------------------------------------------------------- |
| |
| The Communications and Operating Systems Research Group (KBS) at the |
| Technische Universitaet Berlin is currently working on a set of |
| UNIX-based tools for computer-mediated telecooperation that will be |
| made freely available. |
| |
| As part of this effort we are publishing an implementation of the |
| European GSM 06.10 provisional standard for full-rate speech |
| transcoding, prI-ETS 300 036, which uses RPE/LTP (residual pulse |
| excitation/long term prediction) coding at 13 kbit/s. |
| |
| GSM 06.10 compresses frames of 160 13-bit samples (8 kHz sampling |
| rate, i.e. a frame rate of 50 Hz) into 260 bits; for compatibility |
| with typical UNIX applications, our implementation turns frames of 160 |
| 16-bit linear samples into 33-byte frames (1650 Bytes/s). |
| The quality of the algorithm is good enough for reliable speaker |
| recognition; 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), and |
| a library API. Compression and decompression run faster than realtime |
| on most SPARCstations. The implementation has been verified against the |
| ETSI standard test patterns. |
| |
| Jutta Degener (then jutta@cs.tu-berlin.de, nowadays jutta@pobox.com) |
| Carsten Bormann (then cabo@cs.tu-berlin.de, nowadays cabo@tzi.org) |
| |
| Communications and Operating Systems Research Group, TU Berlin |
| Fax: +49.30.31425156, Phone: +49.30.31424315 |
| |
| -- |
| 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. |
