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Re: Aligning NPT syntax with RTSP

From: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
Date: Fri, 29 Jan 2010 11:21:48 +1100
Message-ID: <2c0e02831001281621m7da0b020p2dcf0357c302ba60@mail.gmail.com>
To: Philip Jägenstedt <philipj@opera.com>
Cc: public-media-fragment@w3.org
On Fri, Jan 29, 2010 at 10:05 AM, Philip Jägenstedt <philipj@opera.com> wrote:
> On Wed, 27 Jan 2010 23:28:05 +0100, Silvia Pfeiffer
> <silviapfeiffer1@gmail.com> wrote:
>
>> On Wed, Jan 27, 2010 at 11:45 PM, Philip Jägenstedt <philipj@opera.com>
>> wrote:
>>>
>>> On Wed, 27 Jan 2010 13:32:11 +0100, Silvia Pfeiffer
>>> <silviapfeiffer1@gmail.com> wrote:
>>>
>>>> On Wed, Jan 27, 2010 at 10:33 PM, Philip Jägenstedt <philipj@opera.com>
>>>> wrote:
>>>>>
>>>>> On Wed, 27 Jan 2010 12:23:25 +0100, Silvia Pfeiffer
>>>>> <silviapfeiffer1@gmail.com> wrote:
>>>>>
>>>>>> On Wed, Jan 27, 2010 at 10:09 PM, Philip Jägenstedt
>>>>>> <philipj@opera.com>
>>>>>> wrote:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> http://www.w3.org/2008/WebVideo/Fragments/WD-media-fragments-spec/#npttime
>>>>>>>
>>>>>>> This is what I mentioned in the teleconf. As it is, '0.' would not be
>>>>>>> a
>>>>>>> valid production of npttime but it is a valid production of npt-sec
>>>>>>> from
>>>>>>> RTSP [1]. The same is true of '00:00:00.'. The difference is in
>>>>>>> digits
>>>>>>> after
>>>>>>> the decimal point.
>>>>>>
>>>>>> We currently have:
>>>>>>
>>>>>> npttime    ::=          ( 1*DIGIT [ "." 1*DIGIT ] [ timeunit ] ) |
>>>>>>                      ( 1*DIGIT ":" 2DIGIT ":" 2DIGIT [ "." 1*DIGIT] )
>>>>>>
>>>>>> which I think you are proposing to change to
>>>>>>
>>>>>> npttime    ::=          ( 1*DIGIT [ "." *DIGIT ] [ timeunit ] ) |
>>>>>>                      ( 1*DIGIT ":" 2DIGIT ":" 2DIGIT [ "." *DIGIT] )
>>>>>>
>>>>>> Correct?
>>>>>
>>>>> To be precise, I'm suggesting referring to the definition in RFC2326,
>>>>> noy
>>>>> copying it. The effect is the same of course.
>>>>
>>>> Could do ...  otoh if the RTP spec changes this, we are not
>>>> dependent... and it's really short.
>>>
>>> RFCs can never change, but I have no objections to copying as long as
>>> there
>>> is a (normative?) reference to RFC2326 for readers to follow.
>>
>> Yeah, that's right. I guess the only reason then is not to have to go
>> and read another document.
>> I'm happy to add a normative reference to RFC2326 and still leaven the
>> two-liner in there.
>
> I tried making the edit and it turns out RFC2326 is a bit quirky on the
> HHMMSS format:
>
>   npt-hhmmss   =   npt-hh ":" npt-mm ":" npt-ss [ "." *DIGIT ]
>   npt-hh       =   1*DIGIT     ; any positive number
>   npt-mm       =   1*2DIGIT    ; 0-59
>   npt-ss       =   1*2DIGIT    ; 0-59
>
> It allows 1-digit minute or second, which we currently do not. Do we really
> want this?

I think you may be misreading this. npt-mm and npt-ss say "use one
2DIGIT", i.e. there are two digits always, IMO.

Cheers,
Silvia.
Received on Friday, 29 January 2010 00:22:40 GMT

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