Re: [AVT] Working group last call: draft-ietf-avt-rtp-uemclip-02.txt

Yusuke,

Thank you for your response. Some comments inline - I've deleted the  
points on which we seem to have reached agreement.

On 15 Jan 2008, at 16:21, yusuke hiwasaki wrote:
> At Sun, 13 Jan 2008 15:39:12 +0000, Colin Perkins wrote:
...
>> Section 3.3.1: What is the purpose of the ID field? It would seem to
>> be redundant with the RTP payload type, and so can be removed.
>
> This field is redundant, but it is inform the decoder that what it is
> actually trying to decode a UEMCLIP bitstream. Although it may seem
> redundant, authors prefer to have it as it is.

Why? It just wastes bits - the RTP payload type identifies the bit  
stream as being UEMCLIP.

>> Section 3.3.1.2: What is the purpose of the Check Bit? It would seem
>> that rather than setting a bit to indicate that the payload should be
>> ignored, an MCU should simply not send the packet. The resulting gap
>> in the RTP sequence number space will inform the receiver of the
>> missing data, and trigger packet loss concealment.
>
> There are cases where packet-loss may occur when arriving to an MCU,
> and if the MCU is a signal mixer, the MCU might send a packet
> generated by a best effort. However, this means that the packet sent
> out from MCU may try to convey information of this particular location
> where the packet is lost. This is why Check bits are required.
>
> It is also useful for upward-transcoding from G.711, where all the
> information is not calculated (however, as pointed out, this may be an
> unnecessary procedure, though).
>
> Regarding these fields, authors would like to keep those as it is.

Okay, but I think you need to explain the use case further.

>> Section 6.3.2: Please expand the examples to be complete, valid, SDP
>> files.
>
> Although it might have be incomplete examples, I am not sure if there
> were "invalid" examples (it would have been nice if you could point it
> out), but I will surely revise the examples and hope that the updated
> version is ok.

Sorry - I wasn't clear. The examples are valid fragments of SDP  
files, but it would be desirable to make them valid complete SDP files.

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

_______________________________________________
Audio/Video Transport Working Group
avt@ietf.org
https://www1.ietf.org/mailman/listinfo/avt