There is a need in voice-messaging systems for a feature that allows the user to control the speed of message playback. This capability is generically called “time-scale modification” or TSM within the speech-processing industry. There are many methods of implementing TSM, but the best of them allow the subscriber to stop and start playback as well as to slow down or speed up the message playback by a factor of from 0.5 (half speed) to 1.5 (1.5 times normal speed) while maintaining the fidelity of the original recording played at the original real-time speed (normal speed). The user usually controls the speed by pressing DTMF digits on a telephone handset, ASR (Automatic Speech Recognition) voice commands, or pointing devices on computer-based terminals.
Timescale Modification MST
Features
- Timescale modification from 0.5 to 1.5
- Constant pitch
- Less than three MCPS on the TI TMS320C6000 DSP
- Commetrex OpenMedia and TI XDAIS interfaces
- Portable ANSI C
Benefits
- Enhanced customer experience
- Ease of interfacing
- Easily ported to your environment
License Options
- Limited-use paid-up source code
- Corporate paid-up source code
- Source with runtime license
- Paid-up object code
- Object Code with Runtime Licenses
| COMMAND | PARAMETERS | VALUES |
| Start | None, Speed factor 5-15 | Move the state machine from IDLE to run. The speed factor is set to normal if no parameter is given, otherwise the speed factor of 5-15 is mapped internally to the values 0.5 to 1.5 |
| Pause | None | Suspend operations. Either no output is produced or 0’s depending on the build time parameter. |
| Stop | None | Same as Pause. |
| Resume | None, Speed factor 5-15 | Restarts operations with the last values of last-speed and toggle state. If a speed factor is given the new speed factor is used and the toggle state is set to not-normal |
| Increase | None, Speed factor 5-15 | If no parameter is given, the current speed factor is increased by one unit. If the state is IDLE as a result of a pause, stop or the system having just been started, the current state is moved from IDLE to processing, and the toggle state is set to not-normal. If a parameter is given then the new factor is used, the state is moved from IDLE, and toggle is set to not-normal. |
| Decrease | None, Speed factor 5-15 | If no parameter is given, the current speed factor is decreased by one unit. If the state is IDLE as a result of a pause, stop or the system having just been started, the current state is moved from IDLE to processing, and the toggle state is set to not-normal. If a parameter is given the new factor is used, the state is moved form IDLE, and toggle is set to not-normal. |
| Configure |
Null terminted paramter/value pairs
|
Used to configure run-time operation such as speed factor limits, fill or not-fill output buffers in IDLE, current speed factor and toggle state. |
