Media Types in 3GPP Timed text draft (was: RE: [AVT] RTP
andMediaTypes)
Colin Perkins
csp at csperkins.org
Tue Sep 7 14:58:31 CEST 2004
On 7 Sep 2004, at 13:54, Jose Rey wrote:
...
>> There are other text formats that include formatting modifiers, for
>> example "text/html". I don't understand why their presence would make
>> this a video format.
>
> Ok, I was guiding myself more by the what I understood as type of apps.
> However, just for my clarity: if we wouldn't use the "relaxed rules"
> could I still use text/? Is text/t140 conformat to the 'traditional
> rules'?
None of the RTP payload formats -- not text, audio or video -- can be
used with the 'traditional' rules. This is the reason why the MIME
registration rules are being updated.
>>>>> 2.- we are not clear on what exactly means to "relax rules for
>>>>> media
>>>>> registration under text/". I.e. is text/t140 an example of these
>>>>> "relaxed" rules or does it comply with the traditional rules as per
>>>>> rfc 2046? Does the relaxed rules just mean that besides text also
>>>>> payload headers of that media type are udnerstood?
>>>>
>>>> My understanding is that the new rules are intended to allow formats
>>>> such as 3GPP timed text to be registered under the text top-level
>>>> media
>>>> type, if appropriate, provided their domain of applicability is
>>>> clearly
>>>> specified (e.g. the domain of applicability might be that the type
>>>> is
>>>> defined for transfer via RTP only).
>>>
>>> The MIME subtype /3gpp-tt cannot be used for HTML download since for
>>> that
>>> purpose a 3gp file and therefore the video/3gp MIME type is used.
>>> So I
>>> think this is indeed restricted to RTP. However, what is the gain
>>> of
>>> doing that?
>>
>> My point was that, since this is restricted to transport via RTP, it
>> can be registered under the "text" top-level media type.
>
> What I mean is what would be the use of having two, not one or the
> other.
The media type for the file format may well be different than that for
the RTP payload format, if that's what you mean.
Colin
More information about the Ietf-types
mailing list