23 Oct
2007
23 Oct
'07
1:58 p.m.
Fons,
Thanks for the response.
What you suggested is what I did but I only use one 'silence byte'. That
is definable to match the 'silence byte' for different devices. It seems
to work OK.
Do you think that a range of 'silence bytes' would work better?
William Estrada
MrUmunhum(a)popdial.com
Mt-Umunhum-Wireless.net ( http://Mt-Umunhum-Wireless.net )
Ymessenger: MrUmunhum
Fons Adriaensen wrote:
On Mon, Oct 22, 2007 at 10:17:50AM -0700, william
estrada wrote:
Yes, the format is U8, it is a simple recording
program to make '.wav'
files. The filtering does work when adjusting the 'silence byte'. It
appears that the device drivers are not consistent with this value?
So I will be adding an option to change the value of the 'silence byte'.
How do I use the RMS value to remove noise? A URL that I could read?
It's probably not worth the effort for 8 bits. What you see is a simple
DC offset. Probably the easy approach is to consider a range of values
e.g. 0x7E...0x82 as silence. Any value outside the range starts the
recording, until you find a long series of samples within the silence
range.
So the algo would be:
If you find a value in the silence range, increment a counter.
If the counter reaches a certain value, stop.
If you find a value outside the range, start and reset the
counter.
You could also use a counter to avoid too many false starts.
Ciao