[whatwg] Video playback quality metric

Michael A. Puls II shadow2531 at gmail.com
Mon Feb 23 04:46:00 PST 2009

On Mon, 23 Feb 2009 05:57:01 -0500, Ian Hickson <ian at hixie.ch> wrote:

> On Tue, 10 Feb 2009, Michael A. Puls II wrote:
>> Flash has low, medium and high quality that the user can change
>> (although a lot of sites/players seem to rudely disable that option in
>> the menu for some reason). This helps out a lot and can allow a video to
>> play better. I could imagine an "Auto" option too that automatically
>> switched quality as necessary to get decent playback.
>> As an event, a site could use it like:
>> video.onplaybacktooslow = function() {
>>    this.quality = "low";
>>    this.setToNativeSize(); // stretched videos use more cpu
>> };
>> Or, something like that.
> I'd be interested in seeing what implementors would find easiest to
> expose, once we have more implementation experience.

O.K. Make great sense.

> Just an event along
> the lines of "well I can't keep up with this"? An arbitrary quality
> number where 0 is "this is the worst experience I've ever exposed the
> user to" and 1 is "I'm not even breaking a sweat playing this"? Frames  
> per
> second? Dropped frames per second?
> It should be noted that the spec already supports having the _browser_
> automatically fall back to another stream. The author can include  
> multiple
> streams like this:
>    <video>
>     <source src="hd.mov">
>     <source src="sd.mov">
>     <source src="postage-stamp.mov">
>    </video>
> ...and the browser is well within its rights to decide that it can't play
> hd.mov (having downloaded it and examined it) and that it will use sd.mov
> instead.

The question is, will the browser automatically switch to sd.mov in some situations where the user doesn't want it to? I think that's safe to say.

With that said, good defaults with a way for the user to override (and remember my answer etc.) would probably be the best of both worlds. (I realize that's getting into browser-specific UI/pref stuff, but just saying)


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