EBML specification component for review - Element ID
Erik Piil <[email protected]>
| Newsgroups | gmane.comp.multimedia.matroska.devel |
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| Message-ID | <CAKNa7H_rmaOYQ8JVx64AFcsXDVXGa2mtVHNW60oxZyrivNkYkA@mail.gmail.com> |
This discussion relates to the “Element ID” portion of the earlier EBML RFC Draft for revision/incorporation into the final EBML specification. From the RFC Draft: Element ID The EBML element ID is encoded as a variable size integer with, by default, widths up to 4. Another maximum width value can be set by setting another value to EBMLMaxIDWidth in the EBML header. See section 5.1. IDs are always encoded in their shortest form, e.g. 1 is always encoded as 0x81 and never as 0x4001. This limits the number of IDs in every class with the number of IDs in the previous classes. Furthermore, values with all data bits set to 1 and all data bits set to 0 are reserved, hence the effective number of IDs are as follows for different widths. Note that the shortest encoding form for 127 is 0x407f since 0x7f is reserved. Class Width Number of IDs A 1 2^7-2 = 126 B 2 2^14-2^7 = 16 256 C 3 2^21-2^14 = 2 080 768 D 4 2^28-2^21 = 266 338 304 Any thoughts are most appreciated. Best, Erik _______________________________________________ Matroska-devel mailing list [email protected] http://lists.matroska.org/cgi-bin/mailman/listinfo/matroska-devel Read Matroska-Devel on GMane: http://dir.gmane.org/gmane.comp.multimedia.matroska.devel