[Speex-dev] Preprocessor denoise. Does it work?
andy at plausible.org
Tue Feb 27 15:52:38 PST 2007
Jean-Marc Valin wrote:
> The noise suppressor will only attempt to remove stationary noise,
> such as thermal noise, fans, ... The AGC can indeed do strange
> things in these cases, but it's been improved in svn (compared to
OK, then the problem is that I misunderstood the feature. I assumed
that dynamic squelch was part of it, but it's really something more
along the lines of active noise cancellation. That's fine, I'll work
on improving my own squelch code.
> Congratulations. If it works better on your data, then use it. It'll
> just fail miserably in other conditions, but you may not care about
Uh, production applications almost always require squelch, no? This
is no less true today than it was in the days of analog transmitters.
Note that mobile phones don't transmit low-value transients, even if
I'm typing right next to them. While it's certainly true that the
fixed-threshold static peak implementation I banged out isn't going to
work everywhere, some more elaborate variation would be really nice to
have in speex.
> Are you using a frame size in the 10-20 ms range?
I'm using the frame size returned from SPEEX_GET_FRAME_SIZE. It's 640
frames under this implementation, or 20ms.
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