[whatwg] several messages regarding Ogg in HTML5
singer at apple.com
Tue Dec 11 16:38:46 PST 2007
At 23:20 +0100 11/12/07, alex wrote:
>I have seen this argument pop up now and again, but I have failed to
>actually find the URL to this, could someone post it please?
Hi. It was a record of a discussion at the HTML WG meeting, but
since I wrote it, I guess I can re-post it here (and it doesn't
mention names either).
* * *
The HTML5 specification contains new elements to allow the embedding
of audio and video, similar to the way that images have historically
been embedded in HTML. In contrast to today's behavior, using
object, where the behavior can vary based on both the type of the
object and the browser, this allows for consistent attributes, DOM
behavior, accessibility management, and so on. It also can handle
the time-based nature of audio and video in a consistent way.
However, interoperability at the markup level does not ensure
interoperability for the user, unless there are commonly supported
formats for the video and audio encodings, and the file format
wrapper. For images there is no mandated format, but the widely
deployed solutions (PNG, JPEG/JFIF, GIF) mean that interoperability
is, in fact, achieved.
The problem is complicated by the IPR situation around audio and
video coding, combined with the W3C patent policy
<http://www.w3.org/Consortium/Patent-Policy-20040205/>. "W3C seeks to
issue Recommendations that can be implemented on a Royalty-Free (RF)
basis." Note that much of the rest of the policy may not apply (as
it concerns the specifications developed at the W3C, not those that
are normatively referenced). However, it's clear that at least
RF-decode is needed.
There are, of course, a number of codecs and formats that can be
considered. A non-exhaustive list might include a variety of
'public' codecs, as well, of course, as proprietary ones:
a) open-source projects: the ogg family (vorbis, theora), and the
BBC Dirac video codec project
b) Current ISO/IEC (MPEG) standard codecs, notably the MPEG-4 family:
AVC (14496-10, jointly published with the ITU as H.264), AAC (part of
c) Older MPEG codecs, notably MPEG-2 layer 3 (aka MP3), MPEG-2 layer
1 and 2 audio, and maybe MPEG-4 part 2 video (14496-2)
d) Current standard codecs from other bodies; SMPTE VC-1, for example
e) Older standards from other bodies: ITU recommendations H.263
(with or without its many enhancement annexes) or even H.261
f) Very old standard codecs, formats, or industry practices; notably
the common format for video from digital still cameras (Motion JPEG
with uncompressed audio in an AVI wrapper)
g) Proprietary codecs, such as Dolby AC-3 audio
There are concerns or issues with all of these:
a) a number of large companies are concerned about the possible
unintended entanglements of the open-source codecs; a 'deep pockets'
company deploying them may be subject to risk here;
b) the current MPEG codecs are currently licensed on a royalty-bearing basis;
c) this is also true of the older MPEG codecs; though their age
suggests examining the lifetime of the patents;
d) and also SMPTE VC-1
e) H.263 and H.261 both have patent declarations at the ITU. However,
it is probably worth examining the non-assert status of these, which
parts of the specifications they apply to (e.g. H.263 baseline or its
enhancement annexes), and the age of the patents and their potential
f) This probably doesn't have significant IPR risk, as its wide
deployment in systems should have exposed any risk by now; but it
hardly represents competitive compression.
g) Most proprietary codecs are licensed for payment, as that is the
business of the companies who develop them.
Other licensing concerns:
It's also possible that there are other issues around licensing:
a) variations in licensing depending on filed patents in various geographies
b) restrictions on usage, or fees on usage, other than the fees on
implementation (e.g. usage fees on content sold for remuneration).
It's not entirely clear, also, whether 'implementing' HTML means the
ability to decode and display, or whether encoding is also included.
Including encoding in the equation might significantly complicate
The members of the WG are engineers, not IPR experts. There is
general consensus that a solution is desirable, but also that
engineers are not well placed to find it:
a) they are not experts in the IPR and licensing field;
b) many of them are discouraged by their employers from reading
patents or discussing IPR.
It's clear that the December workshop cannot be silent on this
subject. There must be recognition of the issue and evidence of at
least efforts to solve it, and preferably signs of progress.
It is probable that this is best handled in parallel with the
technical work, and headed by someone 'technically neutral' and
qualified, such as W3C technical and legal staff. A good start would
a) examine the declaration, licensing, and patent expiry situation
for various codecs;
b) contact the licensing authorities for various codecs to determine
their level of interest and flexibility, and possibly invite them to
the December workshop.
c) analyze the open-source codecs for their risk level, and possibly
seek statements from patent owners if that is deemed prudent;
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