RE: Clarification for EXI Options

Dear Rumen,



Your understanding is fully correct.



If the EXI Options are not present in the EXI stream, the EXI decoder must have a way to get the option values (using an out-of-band mechanism) or it will be unable to decode the stream and should disregard it.



The default option values kick in when the EXI options is present in the EXI stream.

As an example, an empty header element (which takes 3 bits to represent) will use only default values. The stream will be encoded in bit-packed mode, without any preservation, without self-contained… Note that in that case the schemaId element is not present. The decoder will need to have an out-of-band mechanism to retrieve the schema to use, if any.



Regards,

                Youenn


From: Rumen Kyusakov [mailto:kjussakov@gmail.com]
Sent: lundi 28 janvier 2013 11:10
To: public-exi@w3.org
Subject: Clarification for EXI Options

Dear all,

I would like to verify with you my interpretation of Section "5.4 EXI Options", EXI Format 1.0.
According to that section "There are no fallback option values provided by this specification for use in the absence of the whole EXI Options part."

This essentially mean that when EXI Options Presence Bit is not set and the decoder is not informed with out-of-band EXI Options it should disregard the EXI stream and not try to parse it using the default values.

In order for the decoder to use the default values the Options Presence Bit must be set and an empty EXI options document must be presented in the header.

A simple response confirming/contradict the statement would be very helpful to me and the EXI community I believe.

Thank you in advance!

Best Regards,
Rumen Kyusakov