[asterisk-users] Codec Conversion

Steve Underwood steveu at coppice.org
Thu Aug 5 19:24:04 CDT 2010


  On 08/06/2010 05:40 AM, Jeff Brower wrote:
> Miguel-
>
>> El 05/08/10 14:50, Tim Nelson escribió:
>>> ----- "michel freiha"<michofr at gmail.com>  wrote:
>>>> Dear Sir,
>>>>
>>>> I tried to convert ilbc to ulaw and get the same result...Bad Voice
>>> Quality
>>>> Regards
>>>>
>>> Again, iLBC is poor quality to begin with. You can't take a poor audio
>>> sample and make it better by converting it to a codec with better
>>> 'resolution'. An audio sample full of robot voice is going to sound
>>> like the same robot voice even if you transcode it to a better quality
>>> codec, whether that is G.729, G.711u, or the latest 'HD Voice' codecs.
>>>
>>> --Tim
>> This just made me remember some comment on the iax.conf sample file...
>>
>> disallow=lpc10            ; Icky sound quality...  Mr. Roboto.
> LPC10 is a very old codec, from early 1980s.  LPC10 doesn't do a good job with pitch detection so it tends to have a
> 'robotic' sound.  With advent of MELPe, anyone needing bitrates 2400 or less should not be using LPC10.
>
> -Jeff
MELPe is patent encumbered, so there is still a place for LPC10. LPC10 
should sound a lot better than the one in Asterisk. The Asterisk codec 
is broken.

Steve




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