FPGA Central

Hi all,

Currently, I am studying on how to get Hi Fidelity effects with ADPC
related compression methods. But it seems that the traditional IMA ADPC
and MS ADPCM will not get the satisfied results.
Any one can give me some suggestions? 16 bit PCM to 5 bit PCM will b
accepted by me.

Thanks in advance.

Jesse

Thanks a lot for your reply. Vladimir and Andor.

Please allow me to explain my problem a little more.

I want to transmit audio with wireless communication method. So data
rate and audio quality are two key points in my research. A month ago,
I found the audio result was not good. And I want to make it improved.

I know from someone that,
16-bit 48kHz to 5 bit 48kHz/interpolated will do the job.

Can you give me some suggestion and useful URL links?

Also thanks a lot.

Jessecw wrote:
> Thanks a lot for your reply. Vladimir and Andor.
>
> Please allow me to explain my problem a little more.
>
> I want to transmit audio with wireless communication method. So data
> rate and audio quality are two key points in my research. A month ago,
> I found the audio result was not good. And I want to make it improved.

Still I can't understand why can't you use the standard audio
compression schemes like mp3 and such. Those schemes were specifically
optimized for the best fidelity at a given bit rate. There are tons of
literature on that.

> I know from someone that,
> 16-bit 48kHz to 5 bit 48kHz/interpolated will do the job.

The direct application of the ADPCM will provide for the fair quality only.

> Can you give me some suggestion and useful URL links?

Take a look at G.722, G.726 and G.727 standards. Although those
algorithms are not directly applicable, you will find some insights there.


Vladimir Vassilevsky

DSP and Mixed Signal Design Consultant

http://www.abvolt.com