[whatwg] Author control over media preloading/buffering
ian at hixie.ch
Mon Feb 23 03:16:14 PST 2009
On Wed, 11 Feb 2009, Robert O'Callahan wrote:
> When a media element loads, reaches the HAVE_CURRENT_DATA state, but is
> paused, and 'autoplay' is not set, we have to decide whether to keep
> downloading data or not. If we expect the user to play the stream, we
> should keep downloading and buffering data to minimize the chance that
> buffering will be needed during playback. But if we don't expect the
> user to play the stream, we should pause the download to conserve
> resources. The latter is especially important on pages with large
> numbers of media elements, only one or two of which the user will play.
> In general it's hard to see how to make a good guess automatically. If a
> page has one (non-autoplay) media element on it, it's hard to know
> whether the user is expected or not expected to play it. For example the
> user might be expected to play it, but only after they've read some text
> before the video (so autoplay is not appropriate). I think (but I'm not
> sure) that authors are likely to be able to make better guesses, so I
> think it would be useful to provide authors with control over this
> decision. I think that authors are likely to want this control in the
> same way they like to be able to preload images.
> So, how about adding an "autobuffer" attribute, which instructs the
> browser that the user will probably play the video and as much data as
> possible should be pre-downloaded? By default (when the attribute is not
> present) the browser would be expected to pause the download after
> reaching HAVE_CURRENT_DATA if the media element is paused and not
I've added this attribute.
On Thu, 12 Feb 2009, timeless wrote:
> if i'm a mobile browser vendor (and I am), and if I expect to use
> Bluetooth to talk to a cell phone which has high bandwidth costs (and if
> you're using an n800/n810 tethered to a phone in Canada, this is true),
> then, i'm not sure I really want web pages to specify things quite like
I've made it clear that the browser doesn't have to autobuffer even if the
attribute is present.
On Fri, 13 Feb 2009, timeless wrote:
> i've seen a lot of places of late which have multiple videos which are
> expected to play in some sort of sequence.
> just saying 'autobuffer' for all of them would kill my device, but a
> suggestion of which ones to buffer in order would be helpful.
On Sat, 14 Feb 2009, Robert O'Callahan wrote:
> Perhaps they should use script to add 'autobuffer' to the next video (or
> just play() it).
That seems to address this use case.
Ian Hickson U+1047E )\._.,--....,'``. fL
http://ln.hixie.ch/ U+263A /, _.. \ _\ ;`._ ,.
Things that are impossible just take longer. `._.-(,_..'--(,_..'`-.;.'
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