[speex-dev] Introduction...

Andrew Baker Andrew at teledesign.co.uk
Wed Feb 19 09:55:48 PST 2003

I've been following this kist for a while now and I suppose I had better 
introduce myself. This is going to be rather a long message, but that 
can't be avoided.

My name is Andrew Baker and I work for a company called TeleDesign. We 
are based in the UK.


I have lots of experience with telecomms, a fair bit with VoIP, quite a 
bit (but rather less recent) with DSPs and some concerning codecs.

I am currently working on a project where I have "end to end" control - 
ie I know about both terminals and what connects them. The terminals at 
each end must be embedded devices. This project requires a codec which 
will compress speech down to around 8kbps.

Looking forward, I am also involved in other projects where a good codec 
is going to be required - especially in the area of embedded devices 
which handle Speex.

I looked around at codecs and the IP issues which surround codecs and 
was shocked. I knew it was all a bit messy - but the situation was far 
worse when examined closely. There is a very substantial barrier to 
innovation and getting products to market.

So I looked around a little further and discovered speex.

Having looked closely at speex, myself and my colleagues have made some 
decisions which I think the people here will find interesting.

A) We are going to do some porting work to Port Speex to the TI range of 
DSPs. Initially we are going to target a TI Floating point device. the 
device we have chosen is the TMS320C6711



B) We will then plan to do some porting work to the TI fixed-point 
range. Most likely TMS320VC5510 - basically because our project is 
battery powered the TI TMS320C55xx series is excellent as regards power 



C) TI within the UK are aware of what we are doing and are supporting us 
in various ways. In principle they seem happy with anything which 
reduces the barrier to entry for products which use their products.

D) We will be releasing our codec on the same licence terms that apply 
to the rest of the Speex project.

E) Our code will be written to all applicable TI recommendations - which 
means it should integrate well with other modules for the TI range of 
DSPs. You should be able to use the speex code in just the same way as 
you can use other codecs and TI DSP software components.

F) I am also trying to persuade a certain large maker of Central-Office 
type VoIP cards to impliment Speex on their products. I haven't 
succeeded yet, but they are showing significant interest and are 
examining the issues carefully. Getting some embedded devices working 
with Speex would also help with this.


So here's the relevant details of our plan. The following is subject to 
change - and any constructive suggestions for change will be seriously 

1) We're going to write a Codec using the DSP starter kit that will 
convert speech at 8/16 kbps 16 bits to/from an 8kbs serial stream.

2) We will some Linux utilities which will allow the TI developer kit to 
be connected to ethernet etc. This connection would require the use of 
one of the standard daughter cards for TI DSP kits - or you could build 
your own (I'm going to) using the adapter plugs and a couple of standard 
chips. I will include suitable schematics in the documentation.

3) We will then port the above codecs to the Integer DSPs

4) All the ports will be tested against the current Speex impliementation(s)

5) My first priority must be the project in hand. However I intend to do 
everything reasonably possible to get the fullest port of speex possible 
- or at least make it easy for others to build on the work I do.



We will be using

2 x TI DSP cards


2 x custom circuit board with UART and serial drivers.

Code will be built using standard TI software tools.

Code will be written with "C" and "C++"

We currently use CVS for source control.

We have the ability to temporarily host CVS on one of our Company 
servers - if there is any interest.

We also have access to Windows 2000 machines and will consider porting 
the Linux Utils to that platform.

Any tools and utilities we create as part of this project will be made 
available on the same terms as the codec proper.

Tools and utilities will be built for the Linux Platform. We currently 
use SUSE 8.1 for our Linux development machines.

I think that's it for now.

Advice, warnings, hints, help and questions - all welcome.

Andrew Baker

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