Jim,
I think it is just a matter of compiler options.
We are using the OSS tools. If no options are set, there are many such warnings, and the resulting H.245 structure is about 32 Mbytes. This seems to be because by default all parts of the structure (except object IDs) are included, as specified, in a union.
To eliminate the warnings and reduce the structure size to something manageable we have used the options --<LINKED SET OF, SEQUENCE OF , OCTET STRING>--
This causes the compiler to create a structure with pointers to objects rather than a structure with the objects included directly.
Best regards
Mike
************************************************************************ * Mike Nilsson Tel: +44 1473 645413 * * Video Processing Unit Fax: +44 1473 643791 * * Centre for Human Communications Email: mike.nilsson@bt-sys.bt.co.uk * * BT Laboratories [MLB3/11] * * Martlesham Heath * * Ipswich IP5 7RE * * UK * ************************************************************************
From: Jim Toga[SMTP:jtoga@jf.intel.com] Sent: 17 February 1998 21:44 To: itu-sg16@mailbag.jf.intel.com Cc: mike.nilsson@BT-SYS.BT.CO.UK; dskran@ascend.com; mreid@videoserver.com Subject: H.245 OCTET STRINGs
It has come to my attention that there are a number of OCTET STRINGS defined in H.245 along the lines of
"h235Key OCTET STRING (SIZE(1..65535))" "value OCTET STRING (SIZE(1..65535))" "certificateResponse OCTET STRING (SIZE(1..65535))OPTIONAL"
The problem with these difinitions is that with the terminating NULL ( I think...) the lentgh goes over by one byte, a 64k block of data. The OSS compiler generates the following warning, which goes away if we change the lenth to '65534'....
"h245.asn", line 1941 (MULTIMEDIA-SYSTEM-CONTROL): C0470W: The size of the generated C structure for the SET OF or SEQUENCE OF exceeds 64K bytes and may adversely affect CPU and memory performance. Consider use of the LINKED or UNBOUNDED directive.
Comments?....fixes?......
jimt.
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