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Re: The problem of having multiple Content-Range headers in HTTP response

From: Yves Lafon <ylafon@w3.org>
Date: Fri, 5 Mar 2010 10:43:59 -0500 (EST)
To: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
cc: raphael.troncy@eurecom.fr, Media Fragment <public-media-fragment@w3.org>
Message-ID: <alpine.DEB.1.10.1003051043370.21692@wnl.j3.bet>
On Thu, 4 Mar 2010, Silvia Pfeiffer wrote:

> On Thu, Mar 4, 2010 at 12:00 AM, Silvia Pfeiffer
> <silviapfeiffer1@gmail.com> wrote:
>> 2010/3/3 Raphaël Troncy <raphael.troncy@cwi.nl>:
>>
>>> Another problem is how should we express that when 2 tracks have been
>>> requested?
>>
>> The background here is that using a comma as in track=audio,subtitle
>> will not work in the HTTP headers, since the comma is used to separate
>> headers from each other. As such, something like:
>>    Content-Range: track audio,subtitle/653.791
>> would be parsed to
>>    Content-Range: track audio
>>    Content-Range: subtitle/653.791
>> which is obviously incorrect.
>
> Incidentally, I just checked on the idea of the "comma" being a header
> separator.
>
> I found this implementation by Microsoft of a Content-Range with a
> different unit range:
> http://msdn.microsoft.com/en-us/library/ee159574%28EXCHG.80%29.aspx
> It uses the comma to separate multiple ranges.
>
> Also, I checked the HTTP specification and wasn't able to find
> anywhere that the comma is indeed used for such header separation.
>
> According to http://www.cs.columbia.edu/sip/syntax/rfc2068.html the
> characters in tspecials are explicitly allowed as field-content.
>
> Yves, can you provide a link to where that use of comma in HTTP header
> fields is forbidden?

<<
Multiple header fields with the same field name MUST NOT be sent in a
    message unless the entire field value for that header field is
    defined as a comma-separated list [i.e., #(values)].  Multiple header
    fields with the same field name can be combined into one "field-name:
    field-value" pair, without changing the semantics of the message, by
    appending each subsequent field value to the combined field value in
    order, separated by a comma.
>>
http://tools.ietf.org/html/draft-ietf-httpbis-p1-messaging-08#section-3.2


-- 
Baroula que barouleras, au tiéu toujou t'entourneras.

         ~~Yves
Received on Friday, 5 March 2010 15:44:03 GMT

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