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Re: [MSE] Timestamp offset mechanism

From: Steven Robertson <strobe@google.com>
Date: Fri, 15 Jun 2012 22:12:28 -0700
Message-ID: <CAJtuSCsMRFa-=EzrkQcV7Wp2duBKxUO=0viU9i-UyOw4ukMF1g@mail.gmail.com>
To: Aaron Colwell <acolwell@google.com>
Cc: public-html-media@w3.org
On Fri, Jun 15, 2012 at 3:40 PM, Aaron Colwell <acolwell@google.com> wrote:
> Which do you prefer?

I prefer sourceTimestampOffset() for two reasons:

- Edit lists and non-rational timescale fractions can complicate the
process of matching the user-specified `segmentTimestamp` to the exact
timestamp parsed from a media segment when using BMFF.

- sourceTimestampMapping() requires a manifest with an entry for every
media segment in order to identify the right value of
`segmentTimestamp` before appending. Since pre-appending all of a
stream's values might leave landmines in the timeline when appending
future segments, this also encourages segments to be handed in
separately. sourceTimestampOffset() is more flexible, allowing data
(or, in the future, URLs) to be added in a less strictly
segment-oriented manner.

> Are you ok with the semantics outlined in the bug description?

Looks good to me, barring one ambiguity: what's the lifetime of this
setting? Does it get reset by an event/method call/initialization
segment, or does it stick around on a source until it is changed by
another call to sourceTimestampOffset()?

Thanks,
Steve
Received on Saturday, 16 June 2012 21:56:53 UTC

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