[Spice-devel] Thoughts about improving streaming video

[Yaniv Kaul]

On 06/28/2011 11:14 AM, John A. Sullivan III wrote:
> On Tue, 2011-06-28 at 09:30 +0200, David Jaša wrote:
>> Dne 28.6.2011 00:39, John A. Sullivan III napsal(a):
>>> On Tue, 2011-06-28 at 00:14 +0200, David Jaša wrote:
>>>> Dne 27.6.2011 20:45, John A. Sullivan III napsal(a):
>>>>> On Mon, 2011-06-27 at 08:32 +0300, Yaniv Kaul wrote:
>>>>>> Licensing and patent concerns of x264 aside (see
>>>>>> http://mailman.videolan.org/pipermail/x264-devel/2010-July/007508.html),
>>>>>> the more I think about it, the more it makes sense to me to have H.264
>>>>>> offload feature in QXL:
>>>>> This sounds great (gaming on SPICE!) but that's a pretty big aside.  How
>>>>> would we handle the patent issues? - John
>>>>>
>>>> Gaming needs 3D acceleration, video needs video acceleration. That's two
>>>> distinct features despite being implemented by the same transistors. :)
>>>>
>>>> Patent issues can be solved pretty easily in an ugly way - make it
>>>> possible to pass any video stream to client if the client claims it
>>>> supports the container + codec, but do not include any patented stuff in
>>>> client by default. Users could observe the U.S. patent law and buy
>>>> codecs from e.g. Fluendo, who will pay the royalties for them, or if
>>>> they don't mind crossing it, they can add support of patented codecs
>>>> themselves.
>>>>
>>> <snip>
>>> <grin>   I was making a reference to the X264 dev in they hyperlink who
>>> exclaimed, "ideoconferencing?  Pah!  I’m playing Call of Duty 4 over a
>>> live video stream!".  Interesting idea though!
>>>
>>> However, more seriously, that is ugly.  Is it really something we would
>>> expect our users to do? Would it completely torpedo most commercial
>>> installation in the contract legal review stage?
>>>
>> It's exactly what Fedora does:
>>
>> ===========================
>>
>> Patent licenses usually require the licensee to pay royalties based on the number of users. Since Fedora is free and open source software, the effective number of users is essentially unrestricted. Patent holders are generally unwilling to give a blanket patent license for unlimited use; moreover, the royalty payments would be too high for it to be practical for the Fedora Project, or its sponsors, to pay them. Proprietary operating systems like Microsoft Windows include the costs of third-party patent licenses paid by Microsoft in the pricing of the product as sold to end users. Fedora is not sold commercially, so there is no way to recoup these substantial expenses.
>>
>> ...
>>
>> Note that Fluendo offers a MP3 plugin for the Gstreamer multimedia framework (used by Totem, Rhythmbox and other multimedia applications) for free and other codecs and DVD player for a price that includes patent licenses. Fedora does not include or endorse these options but you can choose to use them with Fedora if you want to.
>>
>> ==========================
>>
>> (from http://fedoraproject.org/wiki/Software_Patents#Can.27t_you_pay_the_patent_license_fees_for_patent_encumbered_codecs.3F )
>>
>>>    From reading the referenced hyperlink about x264
>>> (http://x264dev.multimedia.cx/archives/249) it sounds like an excellent
>>> solution but only if we can practically surmount the patent issues.
>>> Thoughts?
> <snip>
> Thanks for the reference,  Having read it, I wonder if we should follow
> its advice and focus on VP8 or Theora.  What does RedHat do to deal with
> the issue in large commercial accounts as opposed to Fedora? I suppose
> the big question is if VP8 or Theora has implemented a similar
> on-the-fly encoding scheme as outlined in the referenced x264dev page.

- I cannot and should not speak on behalf of Red Hat regarding patents, 
but the whole idea (or at least my idea) of using x264 was to offload 
H.264 decoding entirely - from the guest all the way to the client. 
Using VP8 or any other decoder would just replace MJPEG's functionality 
today - the guest decompresses (in software) and spice re-compresses (in 
software). I don't think it's good enough.
- Doesn't seem like the other video scheme are prevalent enough nor have 
hardware acceleration support (yet - VP8 has something in the works - 
http://blog.webmproject.org/2011/06/expanding-vp8-hardware-decoder-for-full.html 
. I highly doubt it'll ever get as popular as H.264 HW support is).

Y.

> If no one knows off hand, I wonder if that would be a good place for
> Andrea's project to start - evaluating if those codecs have similar
> implementations to see if they could be used in SPICE as an MJPEG
> alternative - John
>
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