[Speex-dev] Down Convertion from 32Khz to 16Khz

[nir elkayam]

thanks, but actualy this is not my problem.
changing sampling rate may have more problem because of aliasing which need
to be removed.

On Sat, Jun 26, 2010 at 6:18 PM, Clifton Craig <clifton.craig at gmail.com>wrote:

> I've done something similar in Groovy/Java using Wave files. In my case I
> was downsampling from 16bit to 8bit. Here's the core of my conversion logic.
>
> def convertData(def inputStream, def outputStream) {
>    boolean otherByte = false
>    inputStream.eachByte {
>        if(otherByte) {
>            //invert high order byte
>            int inverted = ((int)it) ^ 0x00000080
>            byte[] toWrite = new byte[1]; toWrite[0] = (byte)inverted
>            outputStream.write toWrite
>            otherByte = false
>        } else otherByte = true
>    }
> }
> Basically you need to write every other byte in thePCM sample stream.
>
>
>
> Clifton Craig
> Software Engineer
> http://codeforfun.wordpress.com
> clifton.craig at gmail.com
>
> On Jun 26, 2010, at 9:50 AM, nir elkayam wrote:
>
> > hi
> >
> > on my device i can sample only at 32khz and want to use speex at 16khz so
> i need to down-convert the input signal by factor of 2.
> > does anyone provide me a reference to some code that does that? are there
> any trick to do that?
> >
> > i tried to add to subsequent sample but the result was very bad.
> > what are the requrment from a decimation filter for audio?
> >
> > thanks,
> > nir
> > _______________________________________________
> > Speex-dev mailing list
> > Speex-dev at xiph.org
> > http://lists.xiph.org/mailman/listinfo/speex-dev
>
>


-- 
ניר אלקיים
טל: 050-3930056
nir.elkayam at gmail.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.xiph.org/pipermail/speex-dev/attachments/20100626/325ba918/attachment.htm