Subject: [AVT] RE: Question regarding draft-ietf-avt-rfc2429-bis-09.txt Offer/Answer Mechanism

From: "Osher Hmelnizky" <[email-masked]>
Date: Sun, 4 Jun 2006 16:35:34 +0300

Hi Roni, another question is regarding RFC3016 for MPEG4. 

Is specific profile-level-id requires to support all lower
profile-level-ids?

If we receive an offer of specific profile-level-id, but we support a
larger profile-level-id, can we assume that we also support lower
profile-level-ids?

Regards

Osher

________________________________

From: Even, Roni [mailto:[email-masked]] 
Sent: Sunday, June 04, 2006 4:13 PM
To: Osher Hmelnizky; avt mailing list
Cc: [email-masked]; [email-masked];
[email-masked]; [email-masked]; Oren Kudovitzky; Shahaf Rozanski
Subject: RE: Question regarding draft-ietf-avt-rfc2429-bis-09.txt
Offer/Answer Mechanism

Osher,

1.	If the answerer supports QCIF=2 in sendrecv, then this is the
common mode. It is implied that the offerer can receive QCIF=2 even if
it will not send the re-invite with QCIF=2. The offerer may send the
re-invite to fix the mode so that the answerer will not send him CIF. 
2.	On the Custom - the implied supported resolution is the closest
lowest defined resolution (QCIF, CIF,....)

Roni Even

 

________________________________

From: Osher Hmelnizky [mailto:[email-masked]] 
Sent: Sunday, June 04, 2006 4:04 PM
To: avt mailing list
Cc: Even, Roni; [email-masked];
[email-masked]; [email-masked]; [email-masked]; Oren
Kudovitzky; Shahaf Rozanski; Osher Hmelnizky
Subject: Question regarding draft-ietf-avt-rfc2429-bis-09.txt
Offer/Answer Mechanism

Hi,

According to the draft : " A system that declares support of a specific
MPI for one of the resolutions SHALL also implicitly support a lower
resolution with the same MPI."

If the Answering side supports lower resolution is the following example
is allowed?

For example, if we send an SDP offer:

m=video 6002 RTP/AVP 96

a=rtpmap:96 H263-1998/90000

a=fmtp:96 CIF=2

a=sendrecv

It means that we want to receive CIF with MPI = 2.

If we receive the following answer:

m=video 6002 RTP/AVP 96

a=rtpmap:96 H263-1998/90000

a=fmtp:96 QCIF=2

a=sendrecv

According to H.263 draft: If we receive an offer with a specific MPI for
one of the resolutions, it means that the remote UA also supports a
lower resolution with the same MPI.

Can we negotiate although the parties support different resolutions?

Are these scenarios valid?

What about CUSTOM? How should we negotiate if the parties don't support
the same resolution?

Kind regards

Osher

Hi Roni, another question is regarding RFC3016 for MPEG4. 

Is specific profile-level-id requires to support all lower
profile-level-ids?

If we receive an offer of specific profile-level-id, but we support a
larger profile-level-id, can we assume that we also support lower
profile-level-ids?

Regards

Osher

________________________________

From: Even, Roni [mailto:[email-masked]] 
Sent: Sunday, June 04, 2006 4:13 PM
To: Osher Hmelnizky; avt mailing list
Cc: [email-masked]; [email-masked];
[email-masked]; [email-masked]; Oren Kudovitzky; Shahaf Rozanski
Subject: RE: Question regarding draft-ietf-avt-rfc2429-bis-09.txt
Offer/Answer Mechanism

Osher,

1.	If the answerer supports QCIF=2 in sendrecv, then this is the
common mode. It is implied that the offerer can receive QCIF=2 even if
it will not send the re-invite with QCIF=2. The offerer may send the
re-invite to fix the mode so that the answerer will not send him CIF. 
2.	On the Custom - the implied supported resolution is the closest
lowest defined resolution (QCIF, CIF,....)

Roni Even

 

________________________________

From: Osher Hmelnizky [mailto:[email-masked]] 
Sent: Sunday, June 04, 2006 4:04 PM
To: avt mailing list
Cc: Even, Roni; [email-masked]
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<div class=Section1>

<p class=MsoNormal><font size=2 color="#3366ff" face=Arial><span
style='font-size:10.0pt;font-family:Arial;color:#3366FF'>Hi Roni, another
question is regarding RFC3016 for MPEG4. <o:p></o:p></span></font></p>

<p class=MsoNormal><font size=3 color="#3366ff" face="Times New Roman"><span
style='font-size:12.0pt;color:#3366FF'><o:p>&nbsp;</o:p></span></font></p>

<p class=MsoNormal><font size=3 color="#3366ff" face="Times New Roman"><span
style='font-size:12.0pt;color:#3366FF'>Is specific profile-level-id requires to
support all lower profile-level-ids?<o:p></o:p></span></font></p>

<p class=MsoNormal><font size=3 color="#3366ff" face="Times New Roman"><span
style='font-size:12.0pt;color:#3366FF'>If we receive an offer of specific
profile-level-id, but we support a larger profile-level-id, can we assume that
we also support lower profile-level-ids?<o:p></o:p></span></font></p>

<p class=MsoNormal><font size=3 color="#3366ff" face="Times New Roman"><span
style='font-size:12.0pt;color:#3366FF'><o:p>&nbsp;</o:p></span></font></p>

<p class=MsoNormal><font size=2 color="#3366ff" face=Arial><span
style='font-size:10.0pt;font-family:Arial;color:#3366FF'>Regards<o:p></o:p></span></font></p>

<p class=MsoNormal><font size=2 color="#3366ff" face=Arial><span
style='font-size:10.0pt;font-family:Arial;color:#3366FF'><o:p>&nbsp;</o:p></span></font></p>

<p class=MsoNormal><font size=2 color="#3366ff" face=Arial><span
style='font-size:10.0pt;font-family:Arial;color:#3366FF'>Osher<o:p></o:p></span></font></p>

<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p>&nbsp;</o:p></span></font></p>

<div>

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face="Times New Roman"><span style='font-size:12.0pt'>

<hr size=2 width="100%" align=center tabindex=-1>

</span></font></div>

<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> Even, Roni
[mailto:<st1:PersonName w:st="on">[email-masked]</st1:PersonName>] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Sunday, June 04, 2006 4:13
PM<br>
<b><span style='font-weight:bold'>To:</span></b> <st1:PersonName w:st="on">Osher
 Hmelnizky</st1:Persom;
[email-masked]; [email-masked]; [email-masked]; Oren
Kudovitzky; Shahaf Rozanski; Osher Hmelnizky
Subject: Question regarding draft-ietf-avt-rfc2429-bis-09.txt
Offer/Answer Mechanism

Hi,

According to the draft : " A system that declares support of a specific
MPI for one of the resolutions SHALL also implicitly support a lower
resolution with the same MPI."

If the Answering side supports lower resolution is the following example
is allowed?

For example, if we send an SDP offer:

m=video 6002 RTP/AVP 96

a=rtpmap:96 H263-1998/90000

a=fmtp:96 CIF=2

a=sendrecv

It means that we want to receive CIF with MPI = 2.

If we receive the following answer:

m=video 6002 RTP/AVP 96

a=rtpmap:96 H263-1998/90000

a=fmtp:96 QCIF=2

a=sendrecv

According to H.263 draft: If we receive an offer with a specific MPI for
one of the resolutions, it means that the remote UA also supports a
lower resolution with the same MPI.

Can we negotiate although the parties support different resolutions?

Are these scenarios valid?

What about CUSTOM? How should we negotiate if the parties don't support
the same resolution?

Kind regards

Osher

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