[asterisk-dev] Channel parameters regarding the codec

[David Vossel]

----- Original Message -----
> From: "Nikhil" nikhil at cem-solutions.net>
> To: asterisk-dev at lists.digium.com
> Sent: Monday, August 1, 2011 8:38:48 AM
> Subject: [asterisk-dev] Channel parameters regarding the codec
> Hi
> In asterisk channel ,I so number of variable regarding the Codec ,Can
> anyone explain what are those variable variable means.Below are the
> variables
> 
> 1. chan->readformat
> 

The current audio format that all audio being read from the channel will result in.

> 2. chan->writeformat

The current audio format all audio being written to a channel must be encoded as.

> 
> 3. chan ->rawreadformat

The actual read audio format the underlying channel tech is supplying the channel with.  This may or may not be the same as the readformat.  When the readformat and rawreadformat are different, a translation path is constructed.

> 
> 4. chan ->rawwriteformat

The actual write audio format the underlying channel tech is writing out to the network.  When the writeformat and rawwriteformat is different, a translation path is created.

> 
> 5. chan->nativeformats

A set of audio, video, and text media formats a channel's underlying technology is capable of handling without any translation paths.  raw read and raw write audio formats are picked from this field.

> 
> Thanks
> Nikhil
> 

The whole point of these structures is to allow channels to with differing audio formats to become compatible with one another. We can't change the audio formats a channel's technology private is capable of understanding, but we can build translation paths to get there.

Hope this helps.

~David

-- 
David Vossel
Digium, Inc. | Software Developer, Open Source Software
445 Jan Davis Drive NW - Huntsville, AL 35806 - USA
Check us out at: www.digium.com & www.asterisk.org
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