1*8ec969ceSTreehugger Robot 2*8ec969ceSTreehugger RobotGSM 06.10 13 kbit/s RPE/LTP speech compression available 3*8ec969ceSTreehugger Robot-------------------------------------------------------- 4*8ec969ceSTreehugger Robot 5*8ec969ceSTreehugger RobotThe Communications and Operating Systems Research Group (KBS) at the 6*8ec969ceSTreehugger RobotTechnische Universitaet Berlin is currently working on a set of 7*8ec969ceSTreehugger RobotUNIX-based tools for computer-mediated telecooperation that will be 8*8ec969ceSTreehugger Robotmade freely available. 9*8ec969ceSTreehugger Robot 10*8ec969ceSTreehugger RobotAs part of this effort we are publishing an implementation of the 11*8ec969ceSTreehugger RobotEuropean GSM 06.10 provisional standard for full-rate speech 12*8ec969ceSTreehugger Robottranscoding, prI-ETS 300 036, which uses RPE/LTP (residual pulse 13*8ec969ceSTreehugger Robotexcitation/long term prediction) coding at 13 kbit/s. 14*8ec969ceSTreehugger Robot 15*8ec969ceSTreehugger RobotGSM 06.10 compresses frames of 160 13-bit samples (8 kHz sampling 16*8ec969ceSTreehugger Robotrate, i.e. a frame rate of 50 Hz) into 260 bits; for compatibility 17*8ec969ceSTreehugger Robotwith typical UNIX applications, our implementation turns frames of 160 18*8ec969ceSTreehugger Robot16-bit linear samples into 33-byte frames (1650 Bytes/s). 19*8ec969ceSTreehugger RobotThe quality of the algorithm is good enough for reliable speaker 20*8ec969ceSTreehugger Robotrecognition; even music often survives transcoding in recognizable 21*8ec969ceSTreehugger Robotform (given the bandwidth limitations of 8 kHz sampling rate). 22*8ec969ceSTreehugger Robot 23*8ec969ceSTreehugger RobotThe interfaces offered are a front end modelled after compress(1), and 24*8ec969ceSTreehugger Robota library API. Compression and decompression run faster than realtime 25*8ec969ceSTreehugger Roboton most SPARCstations. The implementation has been verified against the 26*8ec969ceSTreehugger RobotETSI standard test patterns. 27*8ec969ceSTreehugger Robot 28*8ec969ceSTreehugger RobotJutta Degener (then [email protected], nowadays [email protected]) 29*8ec969ceSTreehugger RobotCarsten Bormann (then [email protected], nowadays [email protected]) 30*8ec969ceSTreehugger Robot 31*8ec969ceSTreehugger RobotCommunications and Operating Systems Research Group, TU Berlin 32*8ec969ceSTreehugger RobotFax: +49.30.31425156, Phone: +49.30.31424315 33*8ec969ceSTreehugger Robot 34*8ec969ceSTreehugger Robot-- 35*8ec969ceSTreehugger RobotCopyright 1992 by Jutta Degener and Carsten Bormann, Technische 36*8ec969ceSTreehugger RobotUniversitaet Berlin. See the accompanying file "COPYRIGHT" for 37*8ec969ceSTreehugger Robotdetails. THERE IS ABSOLUTELY NO WARRANTY FOR THIS SOFTWARE. 38