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Re: [todo] Response to your LC Comment -2419 on Media API spec

From: Chris Poppe <Chris.Poppe@UGent.be>
Date: Mon, 01 Nov 2010 12:53:51 +0100
Message-ID: <20101101125351.331143hbeshuakwf@webmail.ugent.be>
To: "Daniel Park" <soohongp@gmail.com>
Cc: tmichel@w3.org, public-media-annotation@w3.org
Dear Daniel, all,

I have sent this mail to the mailinglist so I assume everybody  
can/could read it. I did not get any feedback on this (unless I missed  
something).

Kind regards,
Chris

Quoting "Daniel Park" <soohongp@gmail.com>:

> Chris,
>
> Please do let me know the current status of this comment resolution. Did you
> send this response out to Robin and get his response ? Otherwise, please
> recirculate this thread in the mailing list, and clean up all issues...
>
> Daniel
>
> On Mon, Oct 11, 2010 at 8:35 PM, Chris Poppe <Chris.Poppe@ugent.be> wrote:
>
>> Dear all,
>>
>> I started drafting some answers to Robin's comments on the API doc. It
>> includes a number of questions to the group. Please see my comments inline.
>>
>> Kind regards,
>> Chris
>>
>> -----Original Message-----
>> From: public-media-annotation-request@w3.org
>> [mailto:public-media-annotation-request@w3.org] On Behalf Of Thierry
>> MICHEL
>> Sent: Wednesday, September 29, 2010 6:17 PM
>> To: public-media-annotation@w3.org
>> Subject: [todo] Response to your LC Comment -2419 on Media API spec
>>
>> Robin is not fully satisfied with the following remaining issues.
>> We must respond to Robin on these issues.
>>
>>
>> >> 4 comments are not done yet (for 2 of them we need to contact other
>> WG's,
>> the other 2 require changes to the ontology document).
>> >
>> > Thanks! I would kindly request that you ping me again when these four
>> comments are resolved so that we may ensure alignment. For any response not
>> listed here please consider it assented to.
>>
>>
>> Issue 2419-A:
>> -------------
>> >> substantial: "Example on how to introduce this in HTML5 by making the
>> HTMLMediaElement inherit from the MediaResource interface:" This shouldn't
>> be an example. If a user agent is expected to expose this interface on
>> media
>> elements, then this has to be a MUST, possibly using an "implements"
>> statement.
>> >> [MA] We will coordinate with the HTML WG on this issue.
>> >
>> > I am not certain that you need to coordinate with the HTML WG. This is
>> mostly a Web IDL and testability issue. First, this can't be an example as
>> it is a normative requirement on browsers. You therefore need a statement
>> of
>> the order "User agents that support [HTML5] MUST expose the MediaResource
>> interface on objects that implement HTMLMediaElement." This can be further
>> captured in Web IDL with the simple statement:
>> >    HTMLMediaElement implements MediaResource;
>>
>>
>> [CP] I have added the proposed sentence to the API document: "User agents
>> that support [HTML5] MUST expose the MediaResource interface on objects
>> that
>> implement HTMLMediaElement." (The most recent version of the API document
>> can be found on:
>>
>> http://dev.w3.org/2008/video/mediaann/mediaont-api-1.0/mediaont-api-1.0.html
>> ). And included the proposed Web IDL statement.
>>
>>
>>
>> Issue 2419-B:
>> -------------
>> >> If that is not the case, the API *really* needs to be made asynchronous,
>> otherwise it won't be usable in a browser context at all (or in any kind of
>> performance-conscious environment, such as typically a web server).
>> >> [MA] We have added an asynchronous version of the getMediaProperty
>> method
>> as is used in the Geolocation API
>> (http://dev.w3.org/geo/api/spec-source.html#geolocation).
>> >
>> > It was a mistake in XMLHttpRequest to include both synchronous and
>> asynchronous variants for general consumption - it leads to bad practices,
>> which we should be discouraging by design. What the rest of the Web JS API
>> stack is doing now is to have asynchronous APIs in the regular browser
>> context, and (optionally) synchronous variant only available to Web
>> Workers.
>> See for instance the multiple File APIs. I suggest that you either go full
>> asynchronous, or likewise make the synchronous variant workers-only.
>> >
>> > Is there an updated draft where I can review the changes?
>>
>> [CP] The most recent version of the API document can be found on:
>>
>> http://dev.w3.org/2008/video/mediaann/mediaont-api-1.0/mediaont-api-1.0.html
>>  If needed I guess we can split the API in a synchronous and asynchronous
>> version. What is the opinion of the group on this?
>>
>>
>> >> If it is the case, then instead of specifying a complex filter in
>> getProperty's parameters, it would be a lot simpler to just expose the
>> property and leave it up to code to do the filtering. So instead of
>> >>
>> >> props = mr.getProperty("title");
>> >> props = mr.getProperty("title", "#subchapter");
>> >> props = mr.getProperty("title", null, "tva");
>> >> props = mr.getProperty("title", null, null, null, "fr");
>> >>
>> >> you would just have
>> >>
>> >> props = mr.title;
>> >>
>> >> and leave it up to code to perform any kind of filtering on its own
>> terms. This can then be abstracted into a library. It seems clearer, and
>> much more idiomatic.
>> >> [MA] In fact, when none of the filters are included in the
>> getMediaProperty parameters, the result array will hold all values. So if
>> wanted the code can allways call the property without specifying the
>> filters
>> and do the filtering by itself.
>> >
>> > That does not address the idiomaticity issues - I would need to see the
>> new draft to see if the asynchronous variant improves that.
>>
>> [CP] The asynchronous version does not solve the idiomaticity, it still
>> includes the filtering in the getProperty parameters. I do not see the big
>> advantage of shifting the complexity to the code that is calling the API.
>> In
>> this case the implementation of the API has to return all metadata
>> corresponding to a certain request every time. The filtering would allow to
>> avoid this. Do we need to optimize the ease of implementing the API or of
>> using the API?
>>
>>
>> Issue 2419-C:
>> -------------
>> >> substantial: I suggest exposing the properties directly on the object
>> and
>> removing getPropertyNamesWithValues.
>> >> [MA] We have changed the "getPropertyNamesWithValues" to
>> "getPropertyNamesHavingValues".
>> >
>> > I'm sorry, can you please clarify how this addresses my concern?
>>
>>
>> [CP]It was our opinion that the name getPropertyNamesWithValues might be
>> misleading. This method only returns the names of the properties that would
>> return values if they were requested for using the getMediaProperty method.
>> Therefore the name was renamed. We assumed that your suggestion on exposing
>> the properties directly is related to your previous comment.
>>
>>
>> Issue 2419-D:
>> -------------
>> >> ed.: "MAObject" is not a very descriptive name, 75% of it is dedicated
>> to
>> saying that it's an object, which one already knows from the fact that it
>> has been retrieved as such. "MediaAnnotation" would be clearer.
>> >> [MA] Agreed.
>> >
>> > Has the change been accepted?
>> [CP]Yes, we have renamed the MAObject interface to MediaAnnotation
>> interface.
>>
>>
>> Issue 2419-E:
>> -------------
>> >> substantial: It is not clear "plain text" is for unstructuredValue. Is
>> this the raw binary for binary formats? A piece of XML for XML formats?
>> >> [MA] The unstructuredValue holds the original metadata represented as a
>> string. This can hold binary values from binary formats, XML elements, or
>> anything else. The actual syntax is not defined and can be implementation
>> dependent.
>> >
>> > I would strongly suggest that you reference
>>
>> https://cvs.khronos.org/svn/repos/registry/trunk/public/webgl/doc/spec/Typed
>> Array-spec.html for this (as for instance
>> http://dev.w3.org/2009/dap/file-system/file-writer.html does). Arbitrary
>> data is not really well captured by strings.
>> [CP] I can change the  "attribute DOMString unstructuredValue;"  to
>> "attribute ArrayBuffer unstructeredValue;" and refer to the TypedArray spec
>> like is done in the File API. However, using the ArrayBuffer seems not very
>> adequate for representing strings. So maybe we should have an attribute
>> DOMString unstructeredTextValue; and attribute ArrayBuffer
>> unstructeredBinaryValue;?
>>
>>
>> Issue 2419-F:
>> -------------
>> >> substantial: It is quite counter-intuitive to have:
>> >>
>> >> var lang = foo.getProperty("language").value;
>> >> when one could equally have:
>> >> var lang = foo.language;
>> >>
>> >> The same applies to other properties, such as description.
>> >> [MA] We consider the fact that requesting for one property can result in
>> several results, depending on sub types, source formats, languages and
>> fragments.
>> >> Additionally, the different properties typically have different
>> structure
>> (e.g., language versus rating). We agreed on using only one method to
>> access
>> these properties, consequently
>> >> the different results need to implement the same interface, hence the
>> "value" attribute.
>> >
>> > I am not entirely happy with this design but I guess that it can be
>> wrapped in a library.
>> [CP] So this issue is resolved?
>>
>>
>>
>> Issue 2419-G:
>> -------------
>> >> substantial: The section CreateDate has just "Date" in the interface
>> name. It should probably be "CreationDate" in both.
>> >> [MA] We changed "Date" interface to "CreateDate" interface.
>> >
>> > Shouldn't that be CreationDate?
>> [CP] This would be an ontology issue. I can change this to CreationDate if
>> wanted.
>>
>>
>> Issue 2419-H:
>> -------------
>> >> substantial: It's unclear what to return for Compression. Is JPEG a
>> compression? Something more specific? Is it case sensitive? Partially
>> controlled?
>> >> [MA] TODO This issue will be tackled in the ontology document.
>> >
>> > OK, please inform me of the resolution when it is ready.
>> [CP] This is still not done
>>
>> Issue 2419-I:
>> -------------
>> >> substantial: The relationship of section 5 to HTTP is unclear. Is this
>> needed?
>> >> [MA] Some of the status codes were re-used from HTTP. This section
>> merely
>> elaborates on the status codes and presents the system specific ones.
>> >
>> > It would be worth to indicate that this reuse is (presumably) just to
>> pick
>> something that developers are familiar with, and does not imply any
>> specific
>> link with HTTP.
>> [CP] I have added the latter to the document.
>>
>>
>> Issue 2419-J:
>> -------------
>>
>> >> substantial: Section 7 should be beefed up. Notably, if I can access
>> geographic information it could be used to access someone's location
>> without
>> them agreeing to it. Likewise for name and a number of other things. In
>> general, you probably need to think about privacy.
>> >> [MA] We have added a paragraph on this.
>> >
>> > Can I please see the paragraph? I would like the privacy experts in DAP
>> to
>> look over it.
>> [CP] The paragraph/sentence just holds what you proposed. It can be found
>> in
>>
>> http://dev.w3.org/2008/video/mediaann/mediaont-api-1.0/mediaont-api-1.0.html
>> #security-considerations
>>
>>
>> Issue 2419-K:
>> -------------
>>
>> >> note: integration with DAP's Media Capture is likely desirable.
>> >> [MA] TODO Communication with the Media Capture WG has been initialized.
>> >
>> > I think you mean DAP, but good!
>> >
>> [CP]Joakim, can you check this?
>>
>>
>>
>>
>>
>
>
> --
> Soohong Daniel Park
> Samsung Electronics, DMC R&D
> http://www.soohongp.com, twitter:@natpt
>



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e-mail: Chris.Poppe@ugent.be

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Received on Monday, 1 November 2010 11:54:28 UTC

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