Subject: Re: [AVT] FW: review of audio media types for G.719

From: Magnus Westerlund <[email-masked]>
Date: Wed, 01 Oct 2008 22:36:56 +0200

Hi,

I have responded the following on this:

> Thanks for the review Mark.
> 
> Mark Baker skrev:
>> The interoperability considerations section is empty.  Is that intentional?
> 
> Yes, there isn't much to discuss in this regards as this is a media type for a RTP payload format. You need some external signalling mechanism that either declare or negotiate the features to use. The only interoperability issue here is the support and usage of interleaving. Which is covered in the draft. So what could be done is to add a reference to the relative sections in the RTP payload format.
> 
>>
>> The additional information section is also empty.  You don't need a
>> file extension?
> 
> No, there are ongoing work to define file storage of the G.719 codec. However, that is as part of the ISO based media file format. Thus this media type is not going to be used as a file type at all. And if it is this media type will need an update. 

Cheers

Magnus Westerlund

IETF Transport Area Director & TSVWG Chair
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From: Magnus Westerlund <[email-masked]>
Date: Tue, 07 Oct 2008 13:20:34 +0200

Hi,

I have learned that the file format details for G.719 has been making
progress in ITU-T. Thus I think we can include an informative reference
in the media type about this. The suggested text is:

   Additional Information:

      File storage of G.719 encoded audio in ISO base media file format
      is specified in Annex A of [ITU-T-G719].  Thus media file formats
      such as MP4 (audio/mp4 or video/mp4) [RFC4337] and 3GP (audio/3GPP
      and video/3GPP) [RFC3839] can contain G.719 encoded audio.

I also proposing the following for the Interoperability part:

   Interoperability considerations:

      The support of the Interleaving mode is not mandatory and needs to
      be negotiated.  See Section 7.2 for how to that for SDP based
      protocols.

Comment?

Magnus

Magnus Westerlund skrev:
>> Yes, there isn't much to discuss in this regards as this is a media
>> type for a RTP payload format. You need some external signalling
>> mechanism that either declare or negotiate the features to use. The
>> only interoperability issue here is the support and usage of
>> interleaving. Which is covered in the draft. So what could be done is
>> to add a reference to the relative sections in the RTP payload format.
>>
>>>
>> No, there are ongoing work to define file storage of the G.719 codec.
>> However, that is as part of the ISO based media file format. Thus this
>> media type is not going to be used as a file type at all. And if it is
>> this media type will need an update. 
> 
> 
> Cheers
> 
> Magnus Westerlund
> 

-- 

Magnus Westerlund