# Help with Asterisk Transcoding Please

**URL:** <https://community.asterisk.org/t/help-with-asterisk-transcoding-please/13550>\
**Category:** Asterisk Support\
**Created:** [April 4, 2007, 8:22am UTC](https://community.asterisk.org/t/help-with-asterisk-transcoding-please/13550 "2007-04-04T08:22:52Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![virulence](https://avatars.discourse-cdn.com/v4/letter/v/e56c9b/32.png) [@virulence](https://community.asterisk.org/u/virulence)\
**Post date:** [April 4, 2007, 8:22am UTC](https://community.asterisk.org/t/help-with-asterisk-transcoding-please/13550/1 "2007-04-04T08:22:52Z")

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Anyone know how to enable asterisk to transcode. I’m unable to find a guide for it. Currently, I’m trying to see whether the different codecs such as g711a/g711u/g723/g726-32 are able to communicate with each other. Anyone able to guide me thru? or post me a list of configuration.

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**Author:** ![ianplain](https://sea1.discourse-cdn.com/asterisk/user_avatar/community.asterisk.org/ianplain/32/1776_2.png) [@ianplain](https://community.asterisk.org/u/ianplain)\
**Post date:** [April 4, 2007, 9:20am UTC](https://community.asterisk.org/t/help-with-asterisk-transcoding-please/13550/2 "2007-04-04T09:20:06Z")

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Heres what a vanilla system supports. Add g729 codec to include that and relevent hardware will add g723

` g723 gsm ulaw alaw g726 adpcm slin lpc10 g729 speex ilbc
   g723 - - - - - - - - - - -
    gsm - - 3 3 6 3 2 7 - - 32
   ulaw - 6 - 1 5 2 1 6 - - 31
   alaw - 6 1 - 5 2 1 6 - - 31
   g726 - 8 4 4 - 4 3 8 - - 33
  adpcm - 6 2 2 5 - 1 6 - - 31
   slin - 5 1 1 4 1 - 5 - - 30
  lpc10 - 10 6 6 9 6 5 - - - 35
   g729 - - - - - - - - - - -
  speex - - - - - - - - - - -
   ilbc - 11 7 7 10 7 6 11 - - -
`

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**Author:** ![baconbuttie](https://sea1.discourse-cdn.com/asterisk/user_avatar/community.asterisk.org/baconbuttie/32/916_2.png) [@baconbuttie](https://community.asterisk.org/u/baconbuttie)\
**Post date:** [April 4, 2007, 9:21am UTC](https://community.asterisk.org/t/help-with-asterisk-transcoding-please/13550/3 "2007-04-04T09:21:21Z")

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Asterisk needs a format\_.so and codec\_.so module (/usr/lib/asterisk/modules) to provide transcoding.

to see what codecs Asterisk knows about use “show codecs” at the CLI, and “show translation” to see which it can transcode between.

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<div class="post-metadata">

**Author:** ![virulence](https://avatars.discourse-cdn.com/v4/letter/v/e56c9b/32.png) [@virulence](https://community.asterisk.org/u/virulence)\
**Post date:** [April 5, 2007, 3:21am UTC](https://community.asterisk.org/t/help-with-asterisk-transcoding-please/13550/4 "2007-04-05T03:21:25Z")

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My show core translation:  
Translation times between formats (in milliseconds) for one second of data  
Source Format (Rows) Destination Format (Columns)

```
      g723 gsm ulaw alaw g726aal2 adpcm slin lpc10 g729 speex ilbc g726 g722
 g723 - - - - - - - - - - - - -
  gsm - - 2 2 3 2 1 9 - - 26 3 -
 ulaw - 6 - 1 3 2 1 9 - - 26 3 -
 alaw - 6 1 - 3 2 1 9 - - 26 3 -

```

g726aal2 - 7 3 3 - 3 2 10 - - 27 1 -  
adpcm - 6 2 2 3 - 1 9 - - 26 3 -  
slin - 5 1 1 2 1 - 8 - - 25 2 -  
lpc10 - 8 4 4 5 4 3 - - - 28 5 -  
g729 - - - - - - - - - - - - -  
speex - - - - - - - - - - - - -  
ilbc - 10 6 6 7 6 5 13 - - - 7 -  
g726 - 7 3 3 1 3 2 10 - - 27 - -  
g722 - - -

My show core codecs

## Disclaimer: this command is for informational purposes only. It does not indicate anything about your configuration. INT BINARY HEX TYPE NAME DESC

```
      1 (1 << 0) (0x1) audio g723 (G.723.1)
      2 (1 << 1) (0x2) audio gsm (GSM)
      4 (1 << 2) (0x4) audio ulaw (G.711 u-law)
      8 (1 << 3) (0x8) audio alaw (G.711 A-law)
     16 (1 << 4) (0x10) audio g726aal2 (G.726 AAL2)
     32 (1 << 5) (0x20) audio adpcm (ADPCM)
     64 (1 << 6) (0x40) audio slin (16 bit Signed Linear PCM)
    128 (1 << 7) (0x80) audio lpc10 (LPC10)
    256 (1 << 8) (0x100) audio g729 (G.729A)
    512 (1 << 9) (0x200) audio speex (SpeeX)
   1024 (1 << 10) (0x400) audio ilbc (iLBC)
   2048 (1 << 11) (0x800) audio g726 (G.726 RFC3551)
   4096 (1 << 12) (0x1000) audio g722 (G722)
  65536 (1 << 16) (0x10000) image jpeg (JPEG image)
 131072 (1 << 17) (0x20000) image png (PNG image)
 262144 (1 << 18) (0x40000) video h261 (H.261 Video)
 524288 (1 << 19) (0x80000) video h263 (H.263 Video)
1048576 (1 << 20) (0x100000) video h263p (H.263+ Video)
2097152 (1 << 21) (0x200000) video h264 (H.264 Video)

```

Sorry I’m not very good in reading this … so does it mean that my asterisk server supports all these and why am I still not able to translate if this is so

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<div class="post-metadata">

**Author:** ![pseudoz](https://avatars.discourse-cdn.com/v4/letter/p/8edcca/32.png) [@pseudoz](https://community.asterisk.org/u/pseudoz)\
**Post date:** [April 5, 2007, 12:29pm UTC](https://community.asterisk.org/t/help-with-asterisk-transcoding-please/13550/5 "2007-04-05T12:29:18Z")

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Perhaps, you didn’t add:  
allow=all  
to the configure file of the channel you use (iax2.conf, sip.conf, whatever).  
Also check that translations are alloweded to the peers.