Alexandre Lision | 8af73cb | 2013-12-10 14:11:20 -0500 | [diff] [blame] | 1 | |
| 2 | GSM 06.10 13 kbit/s RPE/LTP speech compression available |
| 3 | -------------------------------------------------------- |
| 4 | |
| 5 | The Communications and Operating Systems Research Group (KBS) at the |
| 6 | Technische Universitaet Berlin is currently working on a set of |
| 7 | UNIX-based tools for computer-mediated telecooperation that will be |
| 8 | made freely available. |
| 9 | |
| 10 | As part of this effort we are publishing an implementation of the |
| 11 | European GSM 06.10 provisional standard for full-rate speech |
| 12 | transcoding, prI-ETS 300 036, which uses RPE/LTP (residual pulse |
| 13 | excitation/long term prediction) coding at 13 kbit/s. |
| 14 | |
| 15 | GSM 06.10 compresses frames of 160 13-bit samples (8 kHz sampling |
| 16 | rate, i.e. a frame rate of 50 Hz) into 260 bits; for compatibility |
| 17 | with typical UNIX applications, our implementation turns frames of 160 |
| 18 | 16-bit linear samples into 33-byte frames (1650 Bytes/s). |
| 19 | The quality of the algorithm is good enough for reliable speaker |
| 20 | recognition; even music often survives transcoding in recognizable |
| 21 | form (given the bandwidth limitations of 8 kHz sampling rate). |
| 22 | |
| 23 | The interfaces offered are a front end modelled after compress(1), and |
| 24 | a library API. Compression and decompression run faster than realtime |
| 25 | on most SPARCstations. The implementation has been verified against the |
| 26 | ETSI standard test patterns. |
| 27 | |
| 28 | Jutta Degener (jutta@cs.tu-berlin.de) |
| 29 | Carsten Bormann (cabo@cs.tu-berlin.de) |
| 30 | |
| 31 | Communications and Operating Systems Research Group, TU Berlin |
| 32 | Fax: +49.30.31425156, Phone: +49.30.31424315 |
| 33 | |
| 34 | -- |
| 35 | Copyright 1992 by Jutta Degener and Carsten Bormann, Technische |
| 36 | Universitaet Berlin. See the accompanying file "COPYRIGHT" for |
| 37 | details. THERE IS ABSOLUTELY NO WARRANTY FOR THIS SOFTWARE. |