[SIPForum-discussion] SDP attribute codec definitions

[Sandeep Mohapatra]

Hi Malcom,

You can refer to RFC-1890..
The snippet of the codec definitions from RFC-1890 is as follows.

PT         encoding      audio/video    clock rate    channels
                 name          (A/V)          (Hz)          (audio)
      _______________________________________________________________
      0          PCMU          A              8000          1
      1          1016          A              8000          1
      2          G721          A              8000          1
      3          GSM           A              8000          1
      4          unassigned    A              8000          1
      5          DVI4          A              8000          1
      6          DVI4          A              16000         1
      7          LPC           A              8000          1
      8          PCMA          A              8000          1
      9          G722          A              8000          1
      10         L16           A              44100         2
      11         L16           A              44100         1
      12         unassigned    A
      13         unassigned    A
      14         MPA           A              90000        (see text)
      15         G728          A              8000          1
      16--23     unassigned    A
      24         unassigned    V
      25         CelB          V              90000
      26         JPEG          V              90000
      27         unassigned    V
      28         nv            V              90000
      29         unassigned    V
      30         unassigned    V
      31         H261          V              90000
      32         MPV           V              90000
      33         MP2T          AV             90000
      34--71     unassigned    ?
      72--76     reserved      N/A            N/A           N/A
      77--95     unassigned    ?
      96--127    dynamic       ?


--- On Mon, 16/6/08, Malcolm Howlett <malcolm at c3.co.uk> wrote:
From: Malcolm Howlett <malcolm at c3.co.uk>
Subject: [SIPForum-discussion] SDP attribute codec definitions
To: discussion at sipforum.com
Date: Monday, 16 June, 2008, 9:33 PM




 


 






Dear folks 

   

I understand the principle of media attributes in SDP as
specified in RFCs 4566, 2327 etc. I am less clear as to where to find
definitions of attributes for each type of codec. Even for the most common of
codecs such as G711, I must admit I struggle to find a definitive list of attributes,
and what textual form they might take, and to interpret them all for the
setting of the RTP packetisers.  

   

Is there a repository of definitions anywhere, please? 

   

Thanks 

   

Malcolm Howlett 






______________________________________________________________________

This email has been scanned by the MessageLabs Email Security System.

For more information please visit http://www.messagelabs.com/email



CONFIDENTIALITY NOTICE: The contents of this email and its attachments are confidential to persons to whom it is addressed. Its contents may also be legally privileged. If you have received this email in error you may not disseminate, distribute, copy, disclose or use the email or any part of it in any form whatsoever unless authorised by us to do so. If you have received this email in error please notify the sender by replying to this email.



SECURITY: You must understand and accept that communication by email is not a totally secure communications medium.



VIRUSES: Although we have taken steps to ensure this email and its attachments are free from any viruses, we advise that the recipient should ensure that they are virus free.



The company does not, to the extent permitted by law, accept any liability (whether in contract, negligence or otherwise) for any virus infection and/or breaches of security and/or confidentiality in relation to transmissions sent by email.



C3 is the trading name for Computer & Communications Co. Ltd.

Registered in England Number 2488641, VAT Number GB 538 5811 23 

Registered Office: The Jeffreys Building, St John's Innovation Centre, Cowley Road, Cambridge CB4 0WS

______________________________________________________________________

 

_______________________________________________
This is the SIP Forum discussion mailing list
TO UNSUBSCRIBE, or edit your delivery options, please visit
http://sipforum.org/mailman/listinfo/discussion
Post to the list at discussion at sipforum.org


      Best Jokes, Best Friends, Best Food and more. Go to http://in.promos.yahoo.com/groups/bestofyahoo/
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://sipforum.org/pipermail/discussion/attachments/20080617/910ea1b7/attachment-0002.html>