Subject: RE: [MMUSIC] a=mptime not needed ? FW: [Sip-implementors] Multipleptime attributes in the SDP

From: "Christer Holmberg (JO/LMF)" <[email-masked]>
Date: Sun, 11 Sep 2005 18:41:33 +0200

Hi,

I don't believe it is correct. Attributes can be in any order, within a media description, so each ptime would basically overwrite the previous value - or the parser would return an error.

There has, from time to time, been talk about a codec specific ptime attribute. Something like: a=cptime: 98 20

...or something like that.

Regards,

Christer

> -----Original Message-----
> From: [email-masked] 
> [mailto:[email-masked]]On Behalf
> Of Lyons, Terry
> Sent: 9. syyskuuta 2005 20:57
> To: [email-masked]
> Cc: [email-masked]
> Subject: [MMUSIC] a=mptime not needed ? FW: [Sip-implementors]
> Multipleptime attributes in the SDP
> 
> 
> Is this a valid concept, "codec specific attribute"?
> SDP says ptime "is a media attribute".
> 
> - [email-masked]
> 
> 
> -----Original Message-----
> From: [email-masked]
> [mailto:[email-masked]]On Behalf Of
> [email-masked]
> Sent: Wednesday, September 07, 2005 1:33 AM
> To: Kool Guy
> Cc: [email-masked];
> [email-masked]
> Subject: Re: [Sip-implementors] Multiple ptime attributes in the SDP
> 
> Hi,
> 
> ptime is a codec specific attribute. The ptime value 
> corresponds to the
> previous codec specified in the
> attribute list. The multiple ptime attribute can be 
> represented as follows:
> 
>               m=audio 49230 RTP/AVP 96 97 98
>               a=rtpmap:96 L8/8000
>               a=ptime:20
>               a=rtpmap:97 L16/8000
>               a=ptime:25
>               a=rtpmap:98 L16/11025/2
> 
> In the above, ptime=20 corresponds to L8 codec and ptime=25 
> corresponds to
> L16.
> 
> Regards
> Partha
> 
> ------------------------------------------------------------------
> R.Parthasarathi
> Flextronics Software Systems (FSS)- B'lore- India
> Off: +91-80-51069088  Mob: +91-9448383781
> ------------------------------------------------------------------
> 
> _______________________________________________
> mmusic mailing list
> [email-masked]
> https://www1.ietf.org/mailman/listinfo/mmusic
> 

_______________________________________________
mmusic mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/mmusic