Re: [rtcweb] H.264's high-low play (Was: H.264 IPR disclosures (or persistent lack thereof))

[Eric Rescorla <[e-mail]>]

Gili writes:
>  On 15/12/2013 11:04 PM, Eric Rescorla wrote:
> >  On Sun, Dec 15, 2013 at 7:38 PM, cowwoc <[e-mail]> wrote:
> > > I've seen multiple VP8 proponents rate the following options as Acceptable:
> > >
> > > H.261 as MTI
> > > Theora as MTI
> > > Implement two of [H.261, H.264, VP8] as MTI
> > >
> > > They might not love the option but they are willing to accept it as a
> > > compromise. On the flip side, I've seen multiple H.264 backers rate "H.264 s
> > > MTI" as "Yes" and all other options as "No". They did not include a single
> > > option as "Acceptable".
> > You might try taking a closer look at the survey results. I'm not a mind-reader
> > so I don't know what an "H.264 backer" is, but the following people voted
> > positively for H.264 and negatively for VP8. I've listed their votes below
> > (accreting Yes and Acceptable, since the difference doesn't seem relevant
> > here):
> >
> > Stefan Hakkansson   (264, None, 2/3 [VP8, H263, H.264], 263)
> > Bernard Aboba (264 only)
> > Sal Loreto (264, None, 263 only)
> >
> > Perhaps I missed some, since I just went by responses to the thread, but this
> > seems sufficient to demonstrate that your characterization of the data isn't
> > accurate.
>
> On second thought, I think you're right.

At the risk of pressing the point, this seems like it would be a good
time for you to explicitly retract your comments about the motives of
H.264 proponents.


> Based on the limited number of straw poll votes cast so far, people
> objected to codecs for one of two reasons:
>
> IPR concerns
> Video quality

Well, as I've said a number of times, there are people who are
in favor of H.264 because they care about interop with non-WebRTC
H.264 devices. I realize that that's not yet appeared in the
survey results, but it was in JDR's presentation at IETF and
we've only seen a very small number of results.


> Consider what will happen if we end up with "No MTI". Some devices
> will support VP8, others will support H.264. Do people realize that
> sticking a transcoder in the middle exposes you to the exact same IPR
> risks that they are complaining about? I mean, H.264 folks will be
> force to implement VP8 in the transcoder, and VP8 folks will be forced
> to implement H.264 in the transcoder. Doesn't this open you up to the
> same IPR risk as "Both H.264 and VP8 are MTI"?

No, because "you" is different people.

To take a simple example, consider the case of a browser which
implements VP8-only. Clearly, the browser has no H.264 IPR risk, at
the cost of not being able to talk to people who do H.264. However, If
someone else (say a conferencing system) decides to build a system
with a VP8-H.264 transcoder, then *they* are the person incurring the
IPR risk. That's really not the same thing at all.

I'm certainly not suggesting that no-MTI is a good thing, but it
isn't the same as MTI-X from the perspective of IPR exposure.

-Ekr