<HTML><BODY style="word-wrap: break-word; -khtml-nbsp-mode: space; -khtml-line-break: after-white-space; ">Folks,<DIV>MPEG (ISO/IEC JTC1 SC29) sent us an liaison statement asking us to review their draft for a MIME registration of the MPEG-21 file format. I know nothing about the subject matter, but hope some of you could give them a hand. Please direct any technical questions to Save Singer of Apple, <A href="mailto:singer@apple.com">singer@apple.com</A>. Below, please find what I believe they want to register. Their full liaison statement (in a bunch of word files) can be found here: <A href="https://datatracker.ietf.org/public/liaisons.cgi">https://datatracker.ietf.org/public/liaisons.cgi</A>, look for ISO/IEC JTC1 SC29, May 2007</DIV><DIV>Best regards,</DIV><DIV>Stephan</DIV><DIV><BR class="khtml-block-placeholder"></DIV><BLOCKQUOTE type="cite"><DIV class="Example"><SPAN lang="EN-GB" style=""><FONT class="Apple-style-span" face="Courier New">MIME media type name: application</FONT><O:P></O:P></SPAN></DIV><DIV class="Example"><SPAN lang="EN-GB" style=""><FONT class="Apple-style-span" face="Courier New">MIME subtype name: mp21</FONT><O:P></O:P></SPAN></DIV><DIV class="Example"><SPAN lang="EN-GB" style=""><FONT class="Apple-style-span" face="Courier New">Required parameters: none</FONT><O:P></O:P></SPAN></DIV><DIV class="Example"><SPAN lang="EN-GB" style=""><FONT class="Apple-style-span" face="Courier New">Optional parameters: none</FONT><O:P></O:P></SPAN></DIV><DIV class="Example"><SPAN lang="EN-GB" style=""><FONT class="Apple-style-span" face="Courier New">Encoding considerations: base64 IS generally preferred; files are binary and should be transmitted without CR/LF conversion, 7-bit stripping, etc.</FONT><O:P></O:P></SPAN></DIV><DIV class="Example"><SPAN lang="EN-GB" style=""><FONT class="Apple-style-span" face="Courier New">Security considerations: It is possible to inject non-compliant MPEG streams (Audio, Video, and Systems) in the MP21 file to overload the receiver/decoder's buffers. This might compromise the functionality of the receiver or even crash it.</FONT><O:P></O:P></SPAN></DIV><DIV class="Example"><SPAN lang="EN-GB" style=""><FONT class="Apple-style-span" face="Courier New">An MP21 file supports the storage of stream types, including commands that are executed on the terminal such as Digital Item Methods based on ECMASCRIPT for which also bindings to Java(TM) and C++ exists. It is possible to use one or more of the above in a manner non-compliant to MPEG to crash the receiver or temporarily make it unavailable.</FONT><O:P></O:P></SPAN></DIV><DIV class="Example"><SPAN lang="EN-GB" style=""><FONT class="Apple-style-span" face="Courier New">Authentication mechanisms can be used to validate of the sender and the data to prevent security problems due to non-compliant malignant MP21 files.</FONT><O:P></O:P></SPAN></DIV><DIV class="Example"><SPAN lang="EN-GB" style=""><FONT class="Apple-style-span" face="Courier New">Interoperability considerations: A number of interoperating implementations exist within the ISO/IEC 21000 community, and that community has reference software for reading and writing the file format.</FONT><O:P></O:P></SPAN></DIV><DIV class="Example"><SPAN lang="EN-GB" style=""><FONT class="Apple-style-span" face="Courier New">Published specification: ISO/IEC 21000-9:2005</FONT><O:P></O:P></SPAN></DIV><DIV class="Example"><SPAN lang="EN-GB" style=""><FONT class="Apple-style-span" face="Courier New">Applications which use this media type: Multimedia</FONT><O:P></O:P></SPAN></DIV><DIV class="Example"><SPAN lang="EN-GB" style=""><FONT class="Apple-style-span" face="Courier New">Additional information:</FONT><O:P></O:P></SPAN></DIV><P class="Example" style="margin-left:20.0pt"><SPAN lang="EN-GB" style=""><FONT class="Apple-style-span" face="Courier New">Magic number(s): none</FONT><O:P></O:P></SPAN></P><P class="Example" style="margin-left:20.0pt"><SPAN lang="EN-GB" style=""><FONT class="Apple-style-span" face="Courier New">File extension(s): mp21 and mpg21 are both declared at <A href="http://pitch.nist.gov/nics/">http://pitch.nist.gov/nics/</A> and <A href="http://filext.com">http://filext.com</A>/</FONT><O:P></O:P></SPAN></P><P class="Example" style="margin-left:20.0pt"><SPAN lang="EN-GB" style=""><FONT class="Apple-style-span" face="Courier New">Macintosh File Type Code(s): mp21 is registered with Apple.</FONT><O:P></O:P></SPAN></P><DIV class="Example"><SPAN lang="EN-GB" style=""><FONT class="Apple-style-span" face="Courier New">Person & email address to contact for further information: David Singer, <A href="mailto:singer@apple.com">singer@apple.com</A></FONT><O:P></O:P></SPAN></DIV><DIV class="Example"><SPAN lang="EN-GB" style=""><FONT class="Apple-style-span" face="Courier New">Intended usage: COMMON</FONT><O:P></O:P></SPAN></DIV><DIV class="Example"><SPAN lang="EN-GB" style=""><FONT class="Apple-style-span" face="Courier New">Author/Change controller: David Singer, ISO/IEC 21000 file format chair</FONT><O:P></O:P></SPAN></DIV></BLOCKQUOTE></BODY></HTML>