[asterisk-dev] default format for sounds

Tzafrir Cohen tzafrir.cohen at xorcom.com
Sun Sep 21 05:28:32 CDT 2008


Hi

The default format for sounds files is currently GSM. This is done in
the interest of backward-compatibility. However it maens that by default
we get sound of lower quality and with more work by the CPU.

I think it would be nice to switch to a different format (by default).

Switch to a different format rather than just enable a different format:
I suppose that the point of using GSM is to save space. If you suddenly
enable a new format, you lose that benefit.

* Except those who actually use GSM, and will now have to pay extra CPU.
  GSM encoding is more expensive than GSM decoding.
* But I suspect that those are generally a minority, and most will
  benefit.

Which will be the default format?

Possible contenders:
1. One of alaw/ulaw. A good balance of size and CPU load, assuming 8kHz
   sample rate. This is a raw format and hence can be easily
   concatenated.
2. slin. Does it actually give a better quality than alaw/ulaw? It takes
   more space.
3. wav - Unlike slin, this is not a raw format, and hence can be easily
   be played (tested) by other players.
4. slin16: If we don't want to assume 8kHz sample rate all over.

-- 
               Tzafrir Cohen
icq#16849755              jabber:tzafrir.cohen at xorcom.com
+972-50-7952406           mailto:tzafrir.cohen at xorcom.com
http://www.xorcom.com  iax:guest at local.xorcom.com/tzafrir



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