Ongoing research projects
Choice of the support
The computational complexity of the Celp coders asks powerful workstations or specialised board for run in real time.
We envisage two ways:
For the DSP Board, we have chosen the new TMS320C32 Digital Signal Processor from
Texas Intruments. If you want more information about this floating-point processor, you may consult :
- For the complex coders, we make the porting on a DSP board.
(Digital Signal Processor: TMS320C30, AD2100, ...).
- For the others coders, we use PC or Sun station after simplifications of few coder's block if necessary.
This is the example for the Low Delay Celp at 16 kbit/s (ITU G.728) which runs in real time on a Pentium 90MHz.
TMS320C3x Floating-point DSPs
All the coders that we develop are based on a Coding ToolKit (CTK).
This tool-kit includes the next functions:
- Speech processing functions.
- Filters functions.
- Statistic functions.
- Specialized functions as codebook search for the CELP, pitch determination, ...
- Special training functions of the codebooks (Stochastic codebooks, overlapped codebooks, ...)
This toolkit is written in C++ and follows the structure presented in
"Anals of telecommunications:
The OOBP programming paradigm: a VHDL-like object oriented approach toward developing efficient
DSP software libraries" (Thierry Dutoit, Vincent Fontaine).
Coders adapted to the Coding ToolKit
- The LD_CELP at 16 kbit/s.
- The LD_CELP at 8 kbit/s.
- The CELP at 8 kbit/s.
- The CELP at 4.3 kbit/s.
See Available products
The next coders that will be developed is:
Last updated December 17, 1999, send comments to firstname.lastname@example.org