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							|  |  |  | GSM 06.10 13 kbit/s RPE/LTP speech compression available | 
					
						
							|  |  |  | -------------------------------------------------------- | 
					
						
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							|  |  |  | 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. | 
					
						
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							|  |  |  | 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. | 
					
						
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							|  |  |  | 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 | 
					
						
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										 |  |  | recognition; even music often survives transcoding in recognizable | 
					
						
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											1999-11-15 06:08:50 +00:00
										 |  |  | form (given the bandwidth limitations of 8 kHz sampling rate). | 
					
						
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							|  |  |  | 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. | 
					
						
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							|  |  |  | Jutta Degener (jutta@cs.tu-berlin.de) | 
					
						
							|  |  |  | Carsten Bormann (cabo@cs.tu-berlin.de) | 
					
						
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							|  |  |  | Communications and Operating Systems Research Group, TU Berlin | 
					
						
							|  |  |  | Fax: +49.30.31425156, Phone: +49.30.31424315 | 
					
						
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							|  |  |  | -- | 
					
						
							|  |  |  | 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. |