Hi Qin,
Thanks for the review see inline
Roni
From: payload-bounces(_at_)ietf(_dot_)org
[mailto:payload-bounces(_at_)ietf(_dot_)org] On Behalf
Of Qin Wu
Sent: Tuesday, September 20, 2011 9:16 AM
To: ietf(_at_)ietf(_dot_)org
Cc: payload(_at_)ietf(_dot_)org
Subject: Re: [payload] [Payload] Last Call:
<draft-ietf-payload-rfc3189bis-02.txt> (RTP Payload Format for DV (IEC
61834) Video)) to Proposed Standard
Hi,
I have just read this document and have some minor comments, hope it is not
late to be taken into account.
1. Section 1:
[Qin]: It looks this version extends RFC3189 to support some new features.
However I can not see any dependency to RFC3189 in the introduction section
until
I read the last section in this document, is it more straigtforward and
clear to merge the section 7,8
to the introduction section and clarify how this document is different from
RFC3189.
Roni: This document does not extend but obsolete RFC3189, so it should not
reference it. As for the difference from RFC3189 I think it is better to
have a separate section.
2. Section 3.1.1
"
3.1.1. Media Type Registration for DV Video
Type name: video
Subtype name: DV
Required parameters:
encode: type of DV format. Permissible values for encode are
SD-VCR/525-60,
SD-VCR/625-50,
HD-VCR/1125-60,
HD-VCR/1250-50,
SDL-VCR/525-60,
SDL-VCR/625-50,
314M-25/525-60,
314M-25/625-50,
314M-50/525-60,
314M-50/625-50,
370M/1080-60i,
370M/1080-50i,
370M/720-60p,
370M/720-50p,
306M/525-60 (for backward compatibility),
and 306M/625-50 (for backward compatibility).
"
[Qin]: In section 7, you claim you have removed SMPTE 306M, since it is
covered by SMPTE 314M format.
However in section 3.1.2, the value for SMPTE 306M is still kept in the
encode list. So the question is
where do you remove SMPTE 306M in this document? Why SMPTE 306M in the media
type registration is still kept?
Does this conflict with what you said in the section 7?
The same comment applies in any place of this document where SMPTE 306M is
still kept.
Roni: Maybe change the first bullet of section 7
" Removed SMPTE 306M, since it is covered by SMPTE 314M format"
To
"support for SMPTE 306M is only for backward interoperability, since it is
covered by SMPTE 314M format"
3. Section 3.1.1
"
Optional parameters:
audio: whether the DV stream includes audio data or not.
Permissible values for audio are bundled and none. Defaults to
none.
Encoding considerations:
DV video can be transmitted with RTP as specified in RFCXXXX
(This document). Other transport methods are not specified.
Security considerations:
See Section 4 of RFCXXXX (This document).
Interoperability considerations: NONE
"
[Qin]: Is it real that there is no interoperability consideration since
Interoperability with Previous Implementations is discussed in the section 8
of this document?
Roni: Good, add a reference to section 8 of this RFC
4. Section 3.2.1
"
Note that the examples in RFC3189 (older version of this document)
provides incorrect SDP "a=fmtp" attribute usage.
"
[Qin]: I believe it is not appropriate to spell this note out when this
document is published but you may put
it as errata or in the section 7.
Roni: good point. Maybe discuss it in section 8, since this may be an
interoperability issue
Also not that the syntax " a=fmtp:<payload type> encode=<DV-video encoding>
audio=<audio
bundled>"
Does not have ";" before the audio while the examples have, I think that ";"
should separate between the parameters.
5. Section 3.2.1
"
The required parameter <DV-video encoding> specifies which type of DV
format is used. The DV format name will be one of the following:
SD-VCR/525-60
SD-VCR/625-50
HD-VCR/1125-60
HD-VCR/1250-50
SDL-VCR/525-60
SDL-VCR/625-50
314M-25/525-60
314M-25/625-50
314M-50/525-60
314M-50/625-50
370M/1080-60i
370M/1080-50i
370M/720-60p
370M/720-50p
306M/525-60 (for backward compatibility)
306M/625-50 (for backward compatibility)
"
[Qin]: Why you need to repeat the same text in the section 3.1, why not just
simply reference it described in the section 3.1.
Roni: I do not see this as a major issue. It can stay from my point of view.
6. Section 3.2.1
"
In order to show whether the audio data is bundled into the DV stream
or not, a format specific parameter is defined as below:
"
[Qin]: s/ a format specifc parameter/ a format of specific parameter
Roni: the current text is OK
7. Section 3.2.1
" The optional parameter <audio bundled> will be one of the following:
"
[Qin] s/one of the following/one of the following value.
One question is:
How do you distinguish between required parameter or optional parameter in
the a=fmtp line?
Roni: This is why a ";" should separate between parameters. If audio does
not exist the default is none
8. Section 3.2.2
"
3.2.2. Usage with the SDP Offer/Answer Model
The following considerations apply when using SDP offer-answer
procedures [RFC3264] to negotiate the use of DV payload in RTP:
o The "encode" parameter can be used for sendrecv, sendonly and
recvonly streams. Each encode type MUST use a separate payload
type number.
"
[Qin]: When you are talking about encode, you are using "encoding
type","DV-video encoding", "type of DV format" in the section 3.2,
and using "encode type" in section 3.2.2, should they be the same thing? why
not use the same terminology for consistency?
Roni: The only issue I see is in
"The required parameter <DV-video encoding>" which should be "The required
parameter "encode""
9. Section 3.2.2
"
In an offer for unbundled streams, in order to associate the related
audio and video, the group attribute as defined in the Session
Description Protocol (SDP) Grouping Framework [RFC5888] can be used.
"
[Qin]: Does it worth a exmaple to expain how SDP Grouping Framework can be
used to correlate audio with video data in the section 3.3.1?
Roni: I think that there is example in RFC 5888, so I will leave it to the
authors.
10. Section 3.3.1
"
When this is done, SDP carries several m=?? lines, one for each media
type of the session (see RFC 4566).
"
[Qin]: What do you mean "when this is done"? It is not clear to me from the
context.
Roni: to me it looks like if what is said in the previous sentence.
Regards!
-Qin
----- Original Message -----
From: "The IESG" <iesg-secretary(_at_)ietf(_dot_)org>
To: "IETF-Announce" <ietf-announce(_at_)ietf(_dot_)org>
Cc: payload(_at_)ietf(_dot_)org
Sent: Monday, September 12, 2011 12:24:16 -0700
Subject: [Payload] Last Call: <draft-ietf-payload-rfc3189bis-02.txt>
(DiameterBase Protocol) to Proposed Standard
The IESG has received a request from the Audio/Video Transport Payloads
WG (payload) to consider the following document:
- 'RTP Payload Format for DV (IEC 61834) Video'
<draft-ietf-payload-rfc3189bis-02.txt> as a Proposed Standard
The IESG plans to make a decision in the next few weeks, and solicits
final comments on this action. Please send substantive comments to the
ietf at ietf.org mailing lists by 2011-09-26. Exceptionally, comments may be
sent to iesg at ietf.org instead. In either case, please retain the
beginning of the Subject line to allow automated sorting.
Abstract
This document specifies the packetization scheme for encapsulating
the compressed digital video data streams commonly known as "DV" into
a payload format for the Real-Time Transport Protocol (RTP). This
document obsoletes RFC 3189.
The file can be obtained via
<http://datatracker.ietf.org/doc/draft-ietf-payload-rfc3189bis/>
http://datatracker.ietf.org/doc/draft-ietf-payload-rfc3189bis/
IESG discussion can be tracked via
<http://datatracker.ietf.org/doc/draft-ietf-payload-rfc3189bis/>
http://datatracker.ietf.org/doc/draft-ietf-payload-rfc3189bis/
No IPR declarations have been submitted directly on this I-D.
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