[Freeswitch-users] Audio clipping in mod_conference

[Roland Hänel]

Without exact knowledge, I would guess this is conference-specific, since
in normal one-to-one conversations, there is no such thing as energy-level
detection and audio mixing.

If you consider VAD (voice activity detection) performed by SIP endpoints
(aka phones), this is a similar thing but in this particular case, I have
verified that VAD is not an issue.

Roland


2011/11/3 Hynek Cihlar <hynek.cihlar at gmail.com>

> Is it only conference related or may it affect other apps?
>
> Hynek
>
>
>
> 2011/11/3 Roland Hänel <roland at haenel.me>
>
>> Hi,
>>
>> During thorough testing of our conference solution which is based on
>> FreeSwitch / mod_conference, we noticed some 'audio clipping' during the
>> conference. Typically, if a conference member didn't have audio for some
>> time and then begins to speak, the first syllable will be clipped and
>> cannot be heard by the other conference participants.
>>
>> We ruled out a number of possible causes, and finally discovered that the
>> energy level detection algorith seems to be the source of the problem.
>> Setting the energy level for all participants to "0" heals the problem (of
>> course now the noise might be higher since every participant's noise
>> contributes to the total noise), but this setting is not very useful since
>> the "talking detection" seems to rely on the same level, i.e. with energy
>> "0", all members are marked talking all the time (which effectively renders
>> the "talking" display useless).
>>
>> Is there any chance to tune the energy level detection time (!), or to
>> de-couple talking detection an energy level detection in FreeSwitch?
>>
>> Best regards,
>> Roland
>>
>>
>>
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>
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-- 
Gruß,
Roland
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