Subject: [AVT] RFC2429-bis-09: Usage of INTERLACE parameter

From: "Christer Holmberg \(JO/LMF\)" <[email-masked]>
Date: Tue, 8 Aug 2006 15:45:29 +0200

Hi,

I have a comment on draft-ietf-avt-rfc2429-bis-09.txt.

Chapter 8.1.2 defines the PROFILE, LEVEL and INTERLACE parameters.

The chapter also says: "The optional parameters PROFILE and LEVEL SHALL
NOT be used with any of the other optional parameters."

Now, I understand that one shall not use PROFILE and LEVEL together with
the QCIF, CIF parameters etc. But, as the text is written now you are
not allowed to use PROFILE and LEVEL with INTERLACE either. Isn't that
wrong?

Currently, if I remember correctly, interlacing is an option in profile
7, and you would need the INTERLACE parameter to indicate whether to use
it or not.

I also think the following text is a little confusing:

"This parameter, if supported SHALL have the values "1".  If not
supported, it should not be listed or SHALL have the value "0"

Shouldn't it say "This functionality" instead of "This parameter"?
Because, if you don't support a parameter it's quite obvious you are not
going to list it...

Regards,

Christer

_______________________________________________
Audio/Video Transport Working Group
[email-masked]
https://www1.ietf.org/mailman/listinfo/avt

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From: "Even, Roni" <[email-masked]>
Date: Tue, 8 Aug 2006 16:56:58 +0300

Christer,
The idea is that you can use either profile and level or use the other
optional parameters to specify your capabilities.
This is how it works in H.323 and we tried to make it similar. The other
optional parameters are used only in conversional video conferencing.
The interlace parameter without profile means that the this
functionality is supported without relationship to a specific profile.
The profiles are defined in H.263 annex X which came late for the video
conferencing manufacturer who prefer to list the capabilities as
separate optional parameters and not be the groups defined as profile in
H.323 annex X.
  
Roni Even

> -----Original Message-----
> From: Christer Holmberg (JO/LMF)
[mailto:[email-masked]]
> Sent: Tuesday, August 08, 2006 4:45 PM
> To: [email-masked]
> Subject: [AVT] RFC2429-bis-09: Usage of INTERLACE parameter
> 
> 
> Hi,
>

---

From: "Christer Holmberg \(JO/LMF\)" <[email-masked]>
Date: Wed, 9 Aug 2006 09:28:07 +0200

Hi,

Another issue. 

>The interlace parameter without profile means that the this
functionality is supported without relationship to a specific 
>profile.

The draft says that if no profile is specified, profile 0 is assumed.

Regards,

Christer

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From: "Christer Holmberg \(JO/LMF\)" <[email-masked]>
Date: Thu, 31 Aug 2006 07:49:09 +0200

Hi Roni (or someone else),

Do you have any comments on my previous mail? I still think the issue is
unclear.

Regards,

Christer

> Sent: 9. elokuuta 2006 10:28
> To: Even, Roni; [email-masked]
> Subject: RE: [AVT] RFC2429-bis-09: Usage of INTERLACE parameter
> 
> 
> Hi,
> 
> Another issue. 
>

---

From: "Even, Roni" <[email-masked]>
Date: Thu, 31 Aug 2006 09:03:24 +0300

Christer,
The text in profile is

PROFILE: H.263 profile number, in the range 0 through 10,
      specifying the supported H.263 annexes/subparts based on H.263
      annex X [H263X].  The annexes supported in each profile are listed
      in table X.1 of H.263 annex X.  If no profile or H.263 annex is
      specified than the stream is Baseline H.263 (profile 0 of H.263
      annex X).

So it says that if no profile or H.263 annex
Roni

> Sent: Thursday, August 31, 2006 8:49 AM
> To: Christer Holmberg (JO/LMF); Even, Roni; [email-masked]
> > > Now, I understand that one shall not use PROFILE and LEVEL
together
> > with
> > > 7, and you would need the INTERLACE parameter to indicate whether
to
> > use
> > > Because, if you don't support a parameter it's quite obvious you
are
> > not