- From: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
- Date: Wed, 23 Jun 2010 18:47:45 +1000
- To: Raphaël Troncy <raphael.troncy@eurecom.fr>
- Cc: Media Fragments Working Group WG <public-media-fragment@w3.org>
2010/6/23 Raphaël Troncy <raphael.troncy@eurecom.fr>: > >> 1. RTSP >> We had at some places mentioned that we support RTSP as well as HTTP >> in this specification, but in particular section 5 (media frag >> processing) we are completely focused on HTTP and do not mention how >> the frag resolution could work over RTSP. We should either remove it >> or add a section in 5 that explains how it is done with RTSP. >> mention in: >> * section 1 >> * section 2.2.2 >> * section 5.1 > > I agree with Jack's opinion here. We have one one side the URL syntax which > is common (Section 4) and on the other side the processing which is protocol > dependent, nicely described for HTTP (Section 5). We could certainly add a > section 5.3 (boiler plate to be filled) for processing media fragments on > RTSP. I would actually prefer to put a short section on RTSP in here rather than ignoring the protocol processing part of HTTP. Section 5 is generic enough to allow for any protocol to be described how it works with the URIs we standardise. >> 2. Caching >> Section 3.4 states that in order to get the existing web proxy >> infrastructure to cache media fragment resources, we need to use byte >> ranges. In view of our recent changes - is that actually still true? >> And what happened to section 7.4 - it's completely empty! > > Intentionally left blank :-) "Intentionally left blank" is a blow in the face of everybody who sees this section and thinks they can find out anything about how cached media fragments work. It is not a sentence that should ever appear in a specification that is supposed to be a standard. >> 3. Requirements >> Section 4 has an editorial note from Jack with a list of requirements. >> I wonder if this list should go into the requirements document rather >> than here? Or what part of it should indeed be kept here? > > I like this bulleted points but it should refer back to the UC & > Requirements document. I suggest to add a note here. These are done. >> 4. ABNF unclear >> Section 4.1 has the following bit of ABNF: >> namevalues = namevalue *( "&" namevalue ) >> namevalue = name [ "=" value ] >> name = fragment - "&" - "=" >> value = fragment - "&" >> I am curious what the role of the dashes and the ampersands is in the >> name and value dimensions and why "fragment" is repeated there - >> wouldn't it make a lot more sense to list the different names of the >> dimensions? Also, these bits do not turn up in the summary ABNF at the >> end - that is rather confusing! > > Has the clarification you wrote bee included? This was a misunderstanding by myself. I haven't included a clarification yet, but can do so. >> 5. Clarify "track" dimension >> I am rather confused right now: how did we decide to do multiple >> tracks? In some places we talk about several tracks being able to be >> defined, but only a single track per spec (see 4.3.3 and the >> examples), and in other places we talk about there only being one >> track dimension allowed (D.2 3c and 5.1.2, 5.1.2.1). Can somebody >> clarify? > > We can have multiple tracks, see > http://www.w3.org/2008/WebVideo/Fragments/wiki/WG_Resolutions#Media_Fragment_URI_Syntax, > resolution on 09/03/2010. All the places where we say we can have *only* one > track should be fixed! See other emails - we need to make sure it's consistent and described in the spec. >> 6. Clarify "id" dimension >> I am again confused about "id". I was somehow under the impression >> that we only allowed its use for the time dimension, but section 4.3.4 >> and 7.2 state that it can also be applied to tracks and regions. Also, >> section 5.1.2 contains a editorial note by Davy about the same topic. >> Did we actually clarify this and how it gets resolved? > > We purposely want to say that "id" can be anything (not only temporal) and > CANNOT be combined with another dimension. An "id" refer to a part that an > author has delimited in the media file, it could be spatio-temporal, it > could be track for a period of time, etc. > >> I think because track names are already names, "id" will actually best >> fit for temporal and spatial regions, but it would be cleanest to >> simply allow them only for one dimension - otherwise, how are you >> going to resolve it? > > No, we define the "id" as a convenient and human readable way of addressing > fragment. Theoretically, there is nothing you cannot do if you remove this > dimension. This is just a shortcut to a dimension or a combination of > dimension that you might use so often that you want to give it a name. Hmm... combination of dimensions. Interesting thought.... OK, I think I can let this one go.... but I'm sure it will come back to haunt us. ;-) >> 7. Error cases >> Section 6 is incomplete. We need to discuss Raphael's note on 6.2.1 >> and my paragraph. We need to work on 6.3, 6.4, 6.5 for the >> non-temporal dimensions. > > Agree. We will need to work on this in the coming weeks. During the Sophia > Antipolis F2F meeting, we have even anticipate we might need a dedicated f2f > meeting to progress on this in September/October. OVC @New York might be the > good occasion! Yup, a good idea. Shouldn't hold up the LC! Cheers, Silvia.
Received on Wednesday, 23 June 2010 08:48:37 UTC