История изменений [назад]

Основной принцип - цифровая связь не дает эхо. эхо всегда на границе сред.

В 13-й версии есть функция софтварного буффера..

pro-sip.net *CLI> core show function JITTERBUFFER 

  -= Info about function 'JITTERBUFFER' =- 

[Synopsis]
Add a Jitterbuffer to the Read side of the channel. This dejitters the audio
stream before it reaches the Asterisk core. This is a write only function. 

[Description]
Jitterbuffers are constructed in two different ways. The first always take
three arguments: <max_size>, <resync_threshold>, and <target_extra>.
Alternatively, a single argument of 'default' can be provided, which will
construct the default jitterbuffer for the given <jitterbuffer type>.
The arguments are:
<max_size>: Length in milliseconds of the buffer. Defaults to 200 ms.
<resync_threshold>: The length in milliseconds over which a timestamp
difference will result in resyncing the jitterbuffer. Defaults to 1000ms.
target_extra: This option only affects the adaptive jitterbuffer. It represents
the amount time in milliseconds by which the new jitter buffer will pad its
size. Defaults to 40ms.
Example: Fixed with defaults

 exten => 1,1,Set(JITTERBUFFER(fixed)=default)

Example: Fixed with 200ms max size

 exten => 1,1,Set(JITTERBUFFER(fixed)=200)

Example: Fixed with 200ms max size, resync threshold 1500

 exten => 1,1,Set(JITTERBUFFER(fixed)=200,1500)

Example: Adaptive with defaults

 exten => 1,1,Set(JITTERBUFFER(adaptive)=default)

Example: Adaptive with 200ms max size, 60ms target extra

 exten => 1,1,Set(JITTERBUFFER(adaptive)=200,,60)

Example: Set a fixed jitterbuffer with defaults; then remove it

 exten => 1,1,Set(JITTERBUFFER(fixed)=default)
 exten => 1,n,Set(JITTERBUFFER(disabled)=)

NOTE: If a channel specifies a jitterbuffer due to channel driver configuration
and the JITTERBUFFER function has set a jitterbuffer for that channel, the
jitterbuffer set by the JITTERBUFFER function will take priority and the
jitterbuffer set by the channel configuration will not be applied.

[Syntax]
JITTERBUFFER(jitterbuffer type)

[Arguments]
jitterbuffer type
    fixed: Set a fixed jitterbuffer on the channel.

    adaptive: Set an adaptive jitterbuffer on the channel.

    disabled: Remove a previously set jitterbuffer from the channel.


[See Also]
Not available