[whatwg] HTML5 video: frame accuracy / SMPTE

Philip Jägenstedt philipj at opera.com
Fri Jan 21 13:04:02 PST 2011

On Fri, 21 Jan 2011 20:11:30 +0100, Gregory Maxwell <gmaxwell at gmail.com>  

> On Fri, Jan 21, 2011 at 1:38 PM, Rob Coenen <coenen.rob at gmail.com> wrote:
>> I still want the API to support seeks to exact frames.
>> eg when I build some GUI that allows the user to click on a button that  
>> says
>> "explosion shot 1 at 00:31:02.15" then I want the player to seek to
>> 00:31:02.15 exactly and not to say, 00:31:02.01 simply b/c that's where  
>> a
>> keyframe happens to be.
> It's unthinkable to me that it wouldn't at least offer exact seeking
> as an option. There are too many interesting programmatic things that
> you can't do without exact seeking.  Though I don't think that has
> anything to do with the default behavior. Since the default behavior
> is already inconsistent perhaps it should just be formally declared to
> be at the implementers whim.

Since, as you say, the behavior is currently inconsistent, there is still  
time to agree on something that makes sense and have everyone implement  
that. I think the best default is keyframe seeking and haven't seen any  
strong arguments for accurate seeking as the default yet.

Concretely: Add seek(time, flags) where flags defaults to nothing.  
Accurate seeking would be done via seek(time, "accurate") or some such.  
Setting currentTime is left as is and doesn't set any flags.

Most of the plumbing is already in the spec:  

Philip Jägenstedt
Core Developer
Opera Software

More information about the whatwg mailing list