Subject: [Cellar] WGLC draft-ietf-cellar-matroska --- blocks in general and block structure

From: Martijn van Beurden <[email-masked]>
Date: Fri, 15 Apr 2022 22:48:42 +0200

Hi all,

Chapter 12 starts quite abruptly with 'Bit 0 is the most significant
bit', without explanation to what is meant. I assume that this covers
the bit positions in the table in for example section 12.2. Perhaps
this could be a little more verbose.

I also propose that a little bit of text is added to describe the
context, perhaps a short recap of what the function is of blocks and
where they fit in. I found it difficult to understand what a
BlockGroup actually groups (as it contains only a single block, not a
group of them?), and why a SimpleBlock is more complicated than a
Block. It took a few readings before I understood that a BlockGroup
holds a single Block with other elements providing context, and that
the SimpleBlock instead replaces this flexible context with a rigid,
simple one.

Similarly I also find this bit of text in chapter 7 confusing:

The Cluster Element helps to break up SimpleBlock or BlockGroup
Elements and helps with seeking and error protection.

It seems a little counterintuitive that an element of a higher level
helps to break up an element of a lower level? Perhaps this can be
rephrased to the following, when combined/swapped with the sentence
that follows it

It is RECOMMENDED that the size of each individual Cluster Element be
limited to store no more than 5 seconds or 5 megabytes. Using several
smaller Cluster Elements instead of a single large one helps with
seeking and makes error protection more robust.