W3C home > Mailing lists > Public > public-html@w3.org > March 2011

Re: Change Proposal for ISSUE-147

From: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
Date: Thu, 17 Mar 2011 15:49:53 +1100
Message-ID: <AANLkTi=UCyHA2DoudH_L1bUv2swkiu=jaj7FZtAg7SEu@mail.gmail.com>
To: Sam Ruby <rubys@intertwingly.net>
Cc: Ian Hickson <ian@hixie.ch>, "HTML WG (public-html@w3.org)" <public-html@w3.org>
On Thu, Mar 17, 2011 at 2:58 PM, Sam Ruby <rubys@intertwingly.net> wrote:
> On 03/16/2011 11:19 PM, Ian Hickson wrote:
>>
>> On Thu, 17 Mar 2011, Frank Olivier wrote:
>>>
>>>>> . Setting playbackRate larger than 1.0 for live video will not work.
>>>>
>>>> Sure it will, so long as the playhead is far enough back that there is
>>>> buffered content to play.
>>>
>>> Sure, but what happens when you play through the buffered content and
>>> get to (effectively) a live feed? The author should be able to determine
>>> that effective playback rate is now 1.0 in this outcome - and setting to
>>>>
>>>> 1.0 should not work.
>>
>> The spec already covers this -- it's the same as what happens if you're
>> playing at the rate of 1.0 but you're receiving only one second's worth of
>> media every two seconds.
>>
>> If we're agreed that the browsers _should_ support this, why would we make
>> it effectively optional? Shouldn't this be a quality-of-implementation
>> issue, where browsers try their best to approximate the requested rate and
>> some do a better job than others? It would be equivalent to how some
>> browsers can render canvas faster than others, or how some browsers render
>> text more beautifully than others. We don't say that browsers that don't
>> support rendering text well should simply refuse to add Text nodes to the
>> DOM, right? Why would we require that browsers decide whether or not they
>> can do a good enough job of going at the requested rate and force them to
>> change the playbackRate accordingly?
>>
>> Would reporting the playback quality (e.g. number of frames rendered over
>> the past second of playback as a fraction of the number of frames that
>> would ideally have been rendered during that same period) be an acceptable
>> alternative solution?
>
> If you have something concrete to propose, please do so in the form of a
> Change Proposal by the 18th.

I actually think the discussion is productive and wouldn't want to see
it shut down. It might result in a better change proposal that
everyone may be able to agree with.

Thanks,
Silvia.
Received on Thursday, 17 March 2011 04:50:45 UTC

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