RE: publish LCWD of "The app: URL Scheme"; deadline April 6

HI  Wonsuk et al.

I agree to move “The: App URL Scheme” [1] to LCWD since it is required for packaged web applications.  However, I have a suggestion to add some clarification for media playback.

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.

Thank you.


[1] App URL scheme http://www.w3.org/2012/sysapps/app-uri/


[2] MSE http://www.w3.org/TR/media-source/

[3] EME http://www.w3.org/TR/encrypted-media/

[4] MPEG DASH http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=57623

[5] HTTP http://www.ietf.org/rfc/rfc2616.txt


-------- begin of my proposed text  --------------------
This example shows an app: URL being resolved<http://www.whatwg.org/specs/web-apps/current-work/#resolve-a-url> in [HTML<http://www.w3.org/2012/sysapps/app-uri/#bib-HTML>]. Note that app: URL can be used for media elements and if seekable seeking works for video and audio resources.
Example 2
var img = document.createElement("img");

//the following setter triggers HTML's resolve algorithm
img.src = "example.gif";

//and the expected output:
console.log(img.src === "app://c13c6f30/example.gif") //true

//Append the image to the document
document.body.appendChild(img);
</script>
This example shows a resource within a packaged application being retrieved over [XHR<http://www.w3.org/2012/sysapps/app-uri/#bib-XHR>]. Note that XHR with the HTTP range header can be used for app URL in such case of playing video/audio resources with Media Source Extensions[MSE].
Example 3
function process() {
  // process the resulting data
}

var xhr = new XMLHttpRequest();
xhr.onload = () => process(this.responseText);
xhr.open( "GET", "playlist.json");
xhr.send();

----------- end --------------------

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Tatsuya Igarashi　(Tatsuya.Igarashi@jp.sony.com<mailto:Tatsuya.Igarashi@jp.sony.com>)
Innovative Technology Development Div, System R&D Group
Sony Corporation




From: Wonsuk Lee [mailto:wonsuk11.lee@samsung.com]
Sent: Monday, March 31, 2014 11:17 PM
To: public-sysapps@w3.org
Cc: Mounir Lamouri
Subject: CfC: publish LCWD of "The app: URL Scheme"; deadline April 6


Colleagues,

Marcos reported The app: URL Scheme spec and its tests are done. So it’s time to go CfC for LC in the group.

This is a Call for Consensus (CfC) to publish a Last Call Working Draft (LCWD) of the “The app: URL Scheme” spec using the following ED as the basis: <http://www.w3.org/2012/sysapps/app-uri/>.

This CfC satisfies the group's requirement to "record the group's decision to request advancement" for this LCWD. Note the Process Document states the following regarding the significance/meaning of a LCWD:



[[

http://www.w3.org/2005/10/Process-20051014/tr.html#last-call




Purpose: A Working Group's Last Call announcement is a signal that:



* the Working Group believes that it has satisfied its relevant technical requirements (e.g., of the charter or requirements document) in the Working Draft;



* the Working Group believes that it has satisfied significant dependencies with other groups;



* other groups SHOULD review the document to confirm that these dependencies have been satisfied. In general, a Last Call announcement is also a signal that the Working Group is planning to advance the technical report to later maturity levels.

]]

If you have any comments or concerns about this CfC, please send them to public-sysapps@w3.org<mailto:public-sysapps@w3.org> by April 6 at the latest. Positive response is preferred and encouraged and silence will be considered as agreement with the proposal.

The proposed review period for this LC is 4 weeks.



For the chairs,

Wonsuk.
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이 원 석 (Wonsuk, Lee) / Principal Engineer, Ph.D
SAMSUNG ELECTRONICS Co., LTD. (三星電子)
Mobile: +82-10-5800-3997
E-mail: wonsuk11.lee@samsung.com<mailto:wonsuk11.lee@samsung.com>
http://www.wonsuk73.com/, twitter: @wonsuk73
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