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Re: MPEG2-TS activity in Bugzilla

From: Bob Lund <B.Lund@CableLabs.com>
Date: Thu, 7 Jun 2012 15:43:02 -0600
To: Mark Watson <watsonm@netflix.com>, Glenn Adams <glenn@skynav.com>, Henri Sivonen <hsivonen@iki.fi>, public-html WG <public-html@w3.org>
Message-ID: <CBF67C08.1A03C%b.lund@cablelabs.com>


From: Mark Watson <watsonm@netflix.com<mailto:watsonm@netflix.com>>
To: Glenn Adams <glenn@skynav.com<mailto:glenn@skynav.com>>, Henri Sivonen <hsivonen@iki.fi<mailto:hsivonen@iki.fi>>, public-html WG <public-html@w3.org<mailto:public-html@w3.org>>
Subject: Re: MPEG2-TS activity in Bugzilla


On Jun 7, 2012, at 8:13 AM, Glenn Adams wrote:

What sort of use case, concretely, does "commercial video" mean in the
above sentence? (I have my guesses, but I'd rather not proceed to
discuss strawmen without confirming first.)

to elaborate, the requirement is based on legacy usage, and not related to distribution agreements


I've made the following point a few times in other contexts, so I will try and restrict myself to making it a single time here.

Existing MPEG2 Transport Stream content will generally need to be re-packaged for use with the Media Source extension (or other adaptive streaming solutions). Specifically, it will need to be segmented at appropriate boundaries and you will need to create appropriate Initialization Segments or ensure that the Media Segments themselves contain the necessary information to initialize playback.

In many cases re-encoding - to create the various bitrates in the first place from original source material - is required.

Given the above, it would simplify things for everyone if the re-packaging were done to a common format that is simpler and more appropriate for this application. Specifically the ISO Base Media File format (or equally, WebM if you were re-encoding anyway). I'd cite the extended and convoluted discussions that were necessary to specify MPEG2 TS for DASH compared to the relative simplicity of the ISO Base Media File approach as evidence this assertion.

Said another way, I'm not convinced there is a massive library of "legacy" MPEG2 TS content out there that just happens to be already suitable for adaptive streaming using the Media Source extension.

While not disagreeing with the above statement, that is not to say that legacy MPEG-2 TS content (without adaptive streaming) won't be consumed by HTML5 user agent based clients.


ůMark
Received on Thursday, 7 June 2012 21:43:38 UTC

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