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[AVT] alignment of layers issue
Hi
Given the discussion around alignment of layers and the document
draft-perkins-avt-rapid-rtp-sync-00
I can't get rid of the feeling that there is a probablity that layers may not be aligned of RTCP-SR based suchronization is used.
I am not that worried about clock-skew. The problem I see is rather the update rate of clocks that are used for the NTP. If the update rate is 15msec you already have a relatively high probability that layers may slip (the slip may only be occasional and initial and can probably be fixed in the long run using some magic algo that irons out the 15msec update).
But that put aside. How does the multi-anything decoder know that one or more layers (or views) are misaligned ?.
I can't tell for SVC, MVC and the others but I fail to see how this verification is possible in G.718. The user will experience crap audio but how does the decoder know that one or more layers are misaligned ?.
Regards
Ingemar
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Hi
Given the discussion around alignment of layers and the document
draft-perkins-avt-rapid-rtp-sync-00
I can't get rid of the feeling that there is a probablity that layers may not be aligned of RTCP-SR based suchronization is used.
I am not that worried about clock-skew. The problem I see is rather the update rate of clocks that are used for the NTP. If the update rate is 15msec you already have a relatively high probability that layers may slip (the slip may only be occasional and initial and can probably be fixed in the long run using some magic algo that irons out the 15msec update).
But that put aside. How does the multi-anything decoder know that one or more layers (or views) are misaligned ?.
I can't tell for SVC, MVC and the others but I fail to see how this verification is possible in G.718. The user will experience crap audio but how does the decoder know that one or more layers are misaligned ?.
Regards
Ingemar
***************************************************
Ingemar Johansson
Senior Research Engineer, IETF "nethead"
EAB/TVP - Multimedia Technologies
Ericsson Research Ericsson AB
Box 920 S-971 28 Luleå, Sweden
Tel: +46 (0)8 4043042
ECN: 850-43042
Mobile: +46 (0)730 783289
*******************************************
_______________________________________________
Audio/Video Transport Working Group
avt at ietf.org
https://www.ietf.org/mailman/listinfo/avt
**********************
Ingemar Johansson
Senior Research Engineer, IETF "nethead"
EAB/TVP - Multimedia Technologies
Ericsson Research Ericsson AB
Box 920 S-971 28 Luleå, Sweden
Tel: +46 (0)8 4043042
ECN: 850-43042
Mobile: +46 (0)730 783289
*******************************************
_______________________________________________
Audio/Video Transport Working Group
avt at ietf.org
https://www.ietf.org/mailman/listinfo/avt