Re: [linux-audio-dev] fast linear resampling on ARM - suggestions?

Tobias Scharnberg wrote:

> Hello List,
> I'm trying to find a library or code-snippet in order to do audio
> resampling from 8khz to 44,1khz and from 44,1khz to 8khz. I need to
> resample the data in realtime - resampling a buffer of data, not a
> soundfile. The quality doesn't need to be good so I guess the best
> solution might be linear audio resampling. The device to do the
> resampling on is an ARM CM-X255 running at 400MHz.
>
> I tried out libsamplerate so far but when I tested it with the
> soundfile conversion test program it needed 3,5 secs to sample from
> 8kHz to 44,1 khz for a 1,7 secs audiofile - which is too slow for me.

libsamplerate uses floating point calculations and most ARM CPUs
don't have an FPU.

Julius O. Smith's original resample program used integer arithmetic
and would therefore be a better choice.

However, please do not use linear resampling; its just too crappy.

Erik

-- 
+-----------------------------------------------------------+
  Erik de Castro Lopo
+-----------------------------------------------------------+
"I have never met anyone who can do Scheme, Haskell, and C pointers 
who can't pick up Java in two days, and create better Java code than
people with five years of experience in Java." --
http://www.joelonsoftware.com/articles/ThePerilsofJavaSchools.html