downsampling an audio file

[karthy]

hi,
i have an audio file(.wav) with sampling rate of 128kbps.
i want to downsample it to 8 kbps. i donno much abt downsampling.
where can i find the practical approach for downsampling?
this is very urgent.its part of my project.
plz help me out...

 

[Gunship]

hi,
i have an audio file(.wav) with sampling rate of 128kbps.
i want to downsample it to 8 kbps. i donno much abt downsampling.
where can i find the practical approach for downsampling?
this is very urgent.its part of my project.
plz help me out...

https://www.analog.com/UploadedFile...=sample&fterm=rate&fterm=convert&fterm=sample rate convert&la=en

The above link will show you the concept of how to do resampling.

I will try to explain this in a nutshell. When your sample rate is 128khz,
your maximum spectrum is 64khz. But when you have 8khz sample
rate, you only have 4khz bandwidth. As a result, you need to throw
away all the high frequency and filter the 128khz sampled data downto
4khz bandwidth. This can be done by using a FIR filter running at 128khz
and with a BW of 4khz. Then you can resample the output data with
8khz.

Read the above link carefully. That is where I first learn how to do
sample rate converter 10years ago.

Good luck

Gunship

 

[M!k]

if you're just looking for a program doing that job, take a look at this freeware:
https://www.voxengo.com/r8brain/
It also contains a programming API which enables you to use the converter DLL in your own program


Mik