Subject: Re: [AVT] Fw: I-D Action:draft-wu-avt-rtcp-xr-quality-monitoring-03.txt

From: Colin Perkins <[email-masked]>
Date: Thu, 7 Oct 2010 12:56:47 +0100

Qin,

These changes generally look good, but I do still have some comments:

- Section 4.2 has been rewritten as a General Synchronisation Offset  
Metrics Block. This is a good direction, but the resulting text still  
assumes that only two streams exist. In an RTP multimedia session  
there can be an arbitrary number of streams, with the same RTCP CNAME,  
not just two. I would suggest that this block be written such that one  
stream reports a General Synchronisation Offset of zero, and other  
streams with the same RTCP CNAME report their offset relative to that.  
Note that the streams being synchronised are not necessarily audio and  
video streams.

- Section 5.1 updates the definition of the Frame Type Indicator to be  
a Picture Type Indicator. The intent of the new definition is okay,  
but the text is very unclear. Can you clarify? (same issue later)

- Unlike the other metrics, the TR 101 290 decodability metrics report  
block is entirely MPEG-2 specific. I suggest splitting this into a  
separate draft, since it doesn’t really relate to the other metrics  
defined in this draft.

Colin

On 28 Sep 2010, at 07:53, Qin Wu wrote:
> Hi,
> The new version of draft-wu-avt-rtcp-xr-quality-monitoring-03 is  
> available at:
> http://www.ietf.org/internet-drafts/draft-wu-avt-rtcp-xr-quality-monitoring-03.txt
> which probably address the comments early received on the list.
> Your further comments and suggestions are welcome!
>
> Regards!
> -Qin
> ----- Original Message -----
> From: <[email-masked]>
> To: <[email-masked]>
> Sent: Tuesday, September 28, 2010 2:15 PM
> Subject: I-D Action:draft-wu-avt-rtcp-xr-quality-monitoring-03.txt
>
>
>> A New Internet-Draft is available from the on-line Internet-Drafts  
>> directories.
>>
>> Title           : RTP Control Protocol Extended Reports (RTCP XR)  
>> Report Blocks for Real- time Video Quality Monitoring
>> Author(s)       : W. Wu, et al.
>> Filename        : draft-wu-avt-rtcp-xr-quality-monitoring-03.txt
>> Pages           : 26
>> Date            : 2010-09-27
>>
>> This document defines a set of RTP Control Protocol Extended Reports
>> (RTCP XR) Report Blocks and associated SDP parameters allowing the
>> report of video quality metrics, primarily for video applications of
>> RTP.
>>
>> A URL for this Internet-Draft is:
>> http://www.ietf.org/internet-drafts/draft-wu-avt-rtcp-xr-quality-monitoring-03.txt

-- 
Colin Perkins
http://csperkins.org/

---

From: Qin Wu <[email-masked]>
Date: Wed, 13 Oct 2010 19:39:02 +0800

Hi,:
----- Original Message ----- 
From: "Colin Perkins" <[email-masked]>
To: "Qin Wu" <[email-masked]>
Cc: <[email-masked]>; <[email-masked]>
Sent: Thursday, October 07, 2010 7:56 PM
Subject: Re: [AVT] Fw: I-D Action:draft-wu-avt-rtcp-xr-quality-monitoring-03.txt

Qin,

[Qin]: Good point, I will add some text to the document to fix this issue.

[Qin]: Yes, I will fix this by adding one new defintion of Picture Type.
Instead of distinguishing frame as I, P, B frame, I will classify the picture
type used in the different video algorithm into key frames and derivation frame.
key frame will be used as a reference for predicting other pictures while derivation frame
will derived from Key-frame. Does it make sense?

[Qin]: Okay.

Colin

-- 
Colin Perkins
http://csperkins.org/