[Matroska-devel] Several (minor) issues or underspecified areas in the MKV spec

Steve Lhomme slhomme at matroska.org
Sun Oct 4 15:45:52 CEST 2015

2015-09-29 18:05 GMT+02:00 Michael Bradshaw <mjbshaw at google.com>:
> On Mon, Sep 28, 2015 at 6:35 PM, Dave Rice <dave at dericed.com> wrote:
>> On Sep 28, 2015, at 9:03 PM, Michael Bradshaw <mjbshaw at google.com> wrote:
>> How can the EBMLMaxIDLength be less than 4, when the EBML and Segment IDs
>> are 4 bytes? Shouldn’t the EBML spec require the range to be > 4 and the MKV
>> speck require it be exactly 4?
>> As you note the EBMLMaxIDLength can not be less than 4 because of the
>> 4-byte EBML Element ID. You’ll see the description for EBMLMaxIDLength is
>> clarified here:
>> https://github.com/Matroska-Org/ebml-specification/blob/master/specification.markdown
>> so that it doesn’t hint of less than 4 which is not possible. I think the
>> understanding is that the Matroska spec can constrain the EBMLMaxIDLength to
>> 4 (which means that 4 is the only valid EBMLMaxIDLength for the Matroska
>> docType but another doctype of EBML could use a higher value.
> The reason I ask this question is because the MKV spec says EBMLMaxIDLength
> is "4 or less in Matroska". It's that "or less" that I'm unsure of. I think
> it should probably read "4 in Matroska".

It should read "IDs in Matroska are 4 octets of less". Fixed.

> --Michael Bradshaw
> _______________________________________________
> Matroska-devel mailing list
> Matroska-devel at lists.matroska.org
> http://lists.matroska.org/cgi-bin/mailman/listinfo/matroska-devel
> Read Matroska-Devel on GMane:
> http://dir.gmane.org/gmane.comp.multimedia.matroska.devel

Steve Lhomme
Matroska association Chairman

More information about the Matroska-devel mailing list