Re: Possible simplification: Remove distinction between track "stop" and source "detach"

On 2015-04-15 15:11, Harald Alvestrand wrote:
> In the current specification, we have two concepts related to sources
> and tracks:
>
> - A track can be stop()ed, in which case it is ended.
> - A track can be detached from its source.
>
> The text says:
>
> A) in terminology for "source", we have:
>
> Sources are detached from a track when the track is ended for any reason.
>
> B) Under "Life-cycle and Media Flow", we have:
>
> A MediaStreamTrack can be detached from its source. It means that the
> track is no longer dependent on the source for media data. If no other
> MediaStreamTrack is using the same source, the source will be stopped.
> MediaStreamTrack attributes such as kind and label must not change
> values when the source is detached.
>
> C) Under the "enabled" attribute of a track, we have:
>
> On getting, the attribute must return the value to which it was last
> set. On setting, it must be set to the new value, regardless of whether
> the MediaStreamTrack object has been detached from its source or not.
>
> Under the "stop" function for a track, we have:
>
> 3. Set track's readyState attribute to ended.
>
> 4. Detach track's source.
>
> It seems to me that this is one concept more than we need.
> Whether there is a relationship between a stopped track and its source
> or not is an implementation detail, and we shouldn't be constraining it
> in our API description.
>
> So my suggestion:
>
> In A, C and D, simply remove the text that refers to "Detach".
>
> In B, instead say:
>
> If all MediaStreamTracks that are using the same source are ended, the
> source will be stopped.
>
> I think that simplifies the terminology, and doesn't change any
> observable property of the API.
>
> What do people think?
> (If others like it, I'll file a bug for it.)

I think this is a simplification worth doing.

This will let us refer to properties on the source without having to 
verify that the track has a source attached. A new thing, however, is 
that a track can have a stopped source (attached).

/Adam

Received on Wednesday, 22 April 2015 09:31:56 UTC