- From: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
- Date: Sat, 12 Sep 2009 17:31:57 +1000
- To: Glenn Adams <gadams@xfsi.com>
- Cc: Philippe Le Hegaret <plh@w3.org>, public-tt@w3.org, daniel.weck@gmail.com, werner.bailer@joanneum.at, Gur@captionsinc.com
- Message-ID: <2c0e02830909120031h4bcb9358t337fb4235365bd29@mail.gmail.com>
On Sat, Sep 12, 2009 at 4:53 PM, Glenn Adams <gadams@xfsi.com> wrote: > inline below ([GA]) > > On Sat, Sep 12, 2009 at 1:06 AM, Silvia Pfeiffer < > silviapfeiffer1@gmail.com> wrote: > >> Hi all, >> >> Most of my feedback has been addressed. >> >> Here is a short list of things that I think can still be improved. >> >> However, I do not think any of this should stand in the way of moving the >> specification to CR. >> >> >> 1. ttp:clockMode >> >> There is still no example on what a specification that uses gps, utc and >> local values would look like. >> >> I am particularly worreid about the GPS time coordinates, for which the >> format is not defined anywhere - not even in the given reference for GPS - >> only when I do a bit of a search, I find >> http://tycho.usno.navy.mil/usno_head.html , but that format seems not to >> fit with the rough description given in DFXP as: >> >> "The primary difference between GPS time and UTC time is that GPS time is >> not adjusted for leap seconds, while UTC time is adjusted as follows: UTC = >> TAI (*Temp Atomique International*) + *leap seconds accumulated since >> 1972*. TAI is maintained by the *Bureau International des Poids et >> Mesures* (BIPM) in Sevres, France. The GPS system time is steered to a >> Master Clock (MC) at the US Naval Observatory which is kept within a close >> but unspecified tolerance of TAI." >> >> Maybe it makes sense to remove the gps specification, since it's not >> expected to be substantially different to UTC and since not specifying the >> format properly will mean we won't get interoperable implementations of this >> feature. However, I am not too fussed about leaving it in - it just won't >> get used then. >> > > [GA] GPS based time codes are used in US DTV broadcasts for PSIP, which is > the format of transmitting program event (i.e., EPG) related data; the > normative reference to the US Navy Observatory site is sufficient for anyone > to ascertain the differences between UTC and GPS time codes; > > since most of the world's aviation and naval industry is satisfied with the > definition of GPS time codes, you should be as well, and I leave it to you > (the reader) to research yourself sufficiently the difference between the > two, which is well captured by the description given in DFXP; > I spent half an hour searching for it and I am still unclear what the actual *format* should look like. If it is so clear to you, why not add a simple one-line example? The Web world is what I am concerned about, not the aviation and naval industry and most of the Web world will not have seen a standard GPS timecode format. > 2. Other requested examples as per >> http://www.w3.org/2009/09/dfxp-lc-issues.html >> and >> http://lists.w3.org/Archives/Public/public-tt/2009Jun/0020.html >> would be helpful to add, but are not urgent, since they don't >> fundamentally change the spec. >> > > [GA] I agree it may be helpful, but it is strictly informative, so is not > strictly necessary. Furthermore, nobody is volunteering to create these > examples (are you?). > I would if I even knew for most of these things what an example would look like. I am asking for these examples because they would clarify the spec. > 3. Section ordering >> http://lists.w3.org/Archives/Public/public-tt/2009Jun/0028.html >> I am not overly fussed about, though I think the concrete suggestions I >> made would be trivial to execute and would improve the readability. >> >> > [GA] I'm afraid you underestimate the editorial work involved to do this > reordering, and it adds nothing to the technical content of the document. > Moving a section is not difficult. I have edited other W3C drafts and I know what's involved. > 4. Use of external metadata >> http://lists.w3.org/Archives/Public/public-tt/2009Jun/0034.html >> I may be blind, but I cannot see an example of foreign namespace metadata >> from Dublin Core added in 12.1.1 of http://www.w3.org/TR/ttaf1-dfxp/, see >> ISSUE-137. > > > [GA] You are looking at the wrong version of DFXP. Look at at the current > editor's update at: > > http://dev.w3.org/2008/tt/spec/ttaf1-dfxp.html#metadata-vocabulary-metadata > > look specifically at the last example in 12.1.1 "Example Fragment - Foreign > Element Metadata". > > Excellent - I thought that might be the case. That example clarifies a lot. Thanks for the link. Best Regards, Silvia.
Received on Saturday, 12 September 2009 07:33:04 UTC