[Matroska-devel] Opus in Matroska

Joseph Ashwood ashwood at msn.com
Fri Sep 21 08:50:14 CEST 2012

-----Original Message----- 
From: Ralph Giles
Subject: Re: [Matroska-devel] Opus in Matroska

> That would work for opus, and is easier to implement than pre-roll
> support in the seek algorithm. But it relies on ~80ms fade-ins being
> acceptable. I'd buy that for Opus, but this same issue applies to
> rolling-intra video, except the delay is between one and ten seconds.

> Are you also arguing that displaying corrupt video for the first couple
> of seconds after a seek is the right thing for players to do?

Well the basic technique would be to hold black until fade-in, but (based on 
my personal observations) anything over about 300 ms is noticed, and 500 ms 
would be too much. For a multi-second delay, I don't think this would be a 
good solution. But it does answer my implied question of whether or not such 
preprocessing will be used in other codecs. Clearly, the stopgap of ignoring 
the problem won't solve the rolling-intra video problem, but we now have 
another another data point to find the correct solution.

It also occurred to me that there is a different problem. Its an unusual 
usage case, but when a muxer is used to append one file to another, the gap 
will be odd at least.

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