[Matroska-devel] Opus in Matroska

Steve Lhomme slhomme at matroska.org
Sat Sep 22 17:52:37 CEST 2012


On Fri, Sep 21, 2012 at 1:43 AM, Ralph Giles <giles at thaumas.net> wrote:
> On 12-09-20 4:21 PM, Joseph Ashwood wrote:
>
>> So I contend that from the actual usage standpoint, the addition of 80
>> ms where the codec seems to be just sitting around does not form a real
>> problem.
>
> 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?

>From what I remember of DirectShow and some other frameworks, the
pre-roll/rolling data are never rendered (played). It's just a very
common trick to get the data/timecode pump started.

As for your question, what timecodes do the codec output after a seek
? Whatever seek starting point it corresponds to, minus the internal
delay. For example, seeking at 0ms would output data starting at
-80ms. Or not output them at all if they are considered garbage. It's
up to the codec and transparent to the container.


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