[Speex-dev] Speex Usage

Andras Kadinger bandit at surfnonstop.com
Sat Aug 6 12:39:37 PDT 2011

2011.08.03. 21:16 keltezéssel, John Henry írta:
> Would speex be a valid method for compressing/decompressing audio for
> live communications?
Audio can mean so many things.

Speex is optimized for encoding speech sampled at 8, 16 or 32 kHz (and 
at least 16 bit strongly recommended). It is a waveform codec, so it can 
cope with music (e.g. you can expect reasonable quality hold music 
during calls), but is not designed for it, so for heavy music 
applications you would be better off looking elsewhere; e.g. Vorbis is 
quite nice for everyday lossy music compression, or you could try FLAC 
for lossless, or for something new and low-latency try CELT 
http://www.celt-codec.org/ from Jean-Marc Valin, the author of Speex.
> Trying to find something that I can use that would decrease the
> bandwidth requirements tremendously, and still be able to be performed
> quick enough for live discussion over the air between two
> communications devices.
Speex is quite nice for conversations, especially the higher samplerate 
(16 kHz, 32 kHz) modes - these are rarely provided by other speech 
codecs (at least until recently) let alone free/open source codecs. It 
can scale in both bandwidth and CPU requirements (called "complexity") 
so can fit into a wide range of applications, but if you are thinking 
low-performance CPU embedded (although that is yet again a relative 
term), your mileage might vary.

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