[CELT-dev] A few build problems

Chris Weiland
Sun, 14 Aug 2011 15:07:24 -0000

I'm developing a VoIP application and I would like to use CELT as the
audio codec.  However, I'm running into a few issues.

First, this application is cross platform, and my primary development
environment is Windows.  However, there is no config.h included with
CELT, so I seem to have to make my own.  I managed to get it to build
after a lot of trial and error, but I'm not positive if I've
configured everything exactly properly.  I guess this is more of a
complaint/request that an "official" config.h for Windows be included
in future releases.

Second, I started this project using Speex.  I don't see any reason to
get rid of Speex support (at least for now), so I'd like to keep that
option.  However, I can't link both Speex and CELT at the same time
because the kiss_fft function is defined in both libraries, which
causes the linker to be confused.  I thought that I could simply
remove one, but it looks like each implementation is very different
and each library depends on its own implementation.  Is there any way
around this?

Lastly, documentation is quite sparse for some of the parameters that
I'd like to play around with.  The biggest one is latency.  The demo
page shows a comparison of different latencies that CELT can run at,
but I don't see anything in the API that has anything to do with that.
 Do I simply adjust the frame size?  Also, what is input clipping?
And what exactly does "complexity" control?  Does it have any effect
on latency or bit rate?  How much effect on CPU usage does varying the
complexity make?

Thanks!
Chris