Make scheme work with steaming media

[marcoscaceres]

Elsewhere, Tatsuya Igarashi proposed:

Sony has investigated a feasibility to playback media files within a packaged web application, especially by using Media Source Extensions(MSE) [2] and Encrypted Media Extensions(EME) [3] for offline playback. The App URL scheme is required to use to specify a media file in a package. In this time, we have tested the media playback with File URL of WebView instead of App URL. And we have encountered an issue that HTTP range header does not work correctly to access local file resources. It may be a bug of the web runtime implementation. But it is the background that we think of this clarification. Actually, it would not be noticed that HTTP Range has to be supported for MPEG DASH [4] On demand profile by using MSE.

I suppose that most working group members assume that XHR with “The App URL scheme” fully follows HTTP RFC-2616 [5] and there is no problem with media playback. But it would be nice to clarify that AppURL can be used for video/audio playback as well as other resources, e.g. images. Because media playback is crucial for packaged web applications.

I suggest to add the following notes to the two examples in the “The: App URL Scheme” spec. Also your suggest for this clarification is welcome.