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: [MSE] Timestamp offset mechanism

From: Sunyang (Eric) <eric.sun@huawei.com>
Date: Sun, 17 Jun 2012 13:12:14 +0000
To: Aaron Colwell <acolwell@google.com>
CC: "public-html-media@w3.org" <public-html-media@w3.org>
Message-ID: <9254B5E6361B1648AFC00BA447E6E8C32AEA91B7@szxeml545-mbx.china.huawei.com>

Prefer option2, it seems simple and without maintain a mapping table.

One question, this proposal you make is :
Shift the current media segment A to later (ie. 10 seconds later), so I can insert a AD media segment in this 10 seconds before the shifted media segment?
But how about the adjacent media segment after A? Overlapped by A? Or just continuously shift to 10 seconds later too?



: Aaron Colwell [mailto:acolwell@google.com]
ʱ: 2012616 6:41
ռ: public-html-media@w3.org
: [MSE] Timestamp offset mechanism

Hi,

Bug 17004<https://www.w3.org/Bugs/Public/show_bug.cgi?id=17004> proposes a mechanism for adjusting timestamps inside media segments. This enables seamlessly splicing content together that doesn't originally exist on a common presentation timeline. Inserting advertisements into content is the most straight forward use case. There has been some useful discussion in the bug comments, but we haven't decided on which method signature to use for specifying the timestamp adjustments.

Here are the proposed signatures at this point:

void sourceTimestampMapping(in double presentationTimestamp, in double segmentTimestamp)
 -- or --
void sourceTimestampOffset(in double timestampOffset)

sourceTimestampMapping() just provides a way to say, "I want this timestamp in the segment to map to this presentation time."
sourceTimestampOffset() is basically just saying, "Add this offset to any timestamp in the segment to get the desired presentation time."

Fundamentally they do the exact same thing, but I'm looking for input on which option people feel more comfortable with.

Which do you prefer?
Are you ok with the semantics outlined in the bug description<https://www.w3.org/Bugs/Public/show_bug.cgi?id=17004#c0>?

Aaron

Received on Sunday, 17 June 2012 13:19:27 UTC

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