Re: Default value of "preload" attribute

On Thu, 25 Mar 2010 16:41:20 +0800, Ian Hickson <> wrote:

> On Thu, 25 Mar 2010, Robert O'Callahan wrote:
>> On Thu, Mar 25, 2010 at 12:51 PM, Ian Hickson <> wrote:
>> > On Thu, 25 Mar 2010, Robert O'Callahan wrote:
>> > > The default value of "preload" is currently "auto".
>> >
>> > Actually the spec says the default is UA-defined. "auto" is only a
>> > suggestion.
>> I actually think that leaving the missing value default up to the UA is
>> a mistake. The difference between "auto" and "metadata" for user
>> experience is often going to be significant. I wonder if other
>> implementors actually want their missing value default to be "auto"?
> Given that pretty much the entire attribute's handling is UA-defined, I
> really don't see much point in making the default defined. Certainly I
> don't think it makes sense to make the default be something that
> explicitly cannot be to download everything, since if that's what the  
> user
> wants, that's what the user should get.
> However I don't mind changing the suggestion. What do browsers generally
> default to? If most browsers default to metadata, there's not much point
> suggesting auto. :-)

We haven't implemented preload yet, but I think we'll default to metadata  
(including decoding the first frame). However, this just means that we  
start out conservative, as soon as the the video starts playing (or we  
have some other reason to think it will be used soon) we'll download more  
aggressively. In other words, preload="metadata" just means "conservative"  
and preload="auto" means "aggressive"...

Philip Jägenstedt
Core Developer
Opera Software

Received on Monday, 29 March 2010 04:07:49 UTC