can you guys clarify some of the frame header fields in vp9 and maybe remove some duplicates in vp10?

[GoogleCodeExporter]

This has always been one of these minor annoyances for me, some fields are 
essentially duplicates, or very confusing.

I'll give some examples that I could find:

- the inter frame header has this field called reset_frame_context, and it used 
to be utterly unclear to me what it did (until recently). According to the 
docs, it can have a value [0-3], but 0 and 1 mean the same thing, 3 is a 
duplicate of error_resilient_mode; only 2 seems to have some utility (was this 
measured? is it used in a real encoder?). It feels to me this 4-value thing 
could be a simple boolean at the very least (just 0 or 2), and possibly be 
removed altogether.

- another example is refresh_frame_context and frame_parallel_decoding_mode. 
They both accomplish an inverse of each other: whether to apply backwards 
adaptivity to frame context probabilities or not. One of the two could probably 
be removed.

- the last two are display_width and display_height; I have no idea what they 
are for, and no other codec has such values. Are they to set pixel aspect 
ratio? (Their purpose is undocumented.)

Original issue reported on code.google.com by rsbul...@gmail.com on 22 Jun 2015 at 9:00

[GoogleCodeExporter]

Original comment by ya...@google.com on 10 Jul 2015 at 11:13

• Added labels: Hotlist-VP10-must-fix

[GoogleCodeExporter]

Original comment by ya...@google.com on 10 Jul 2015 at 11:26

• Changed state: Available

[GoogleCodeExporter]

Original comment by ya...@google.com on 14 Jul 2015 at 4:42

• Added labels: Component-libvpx, Type-Enhancement

[GoogleCodeExporter]

Original comment by ya...@google.com on 12 Aug 2015 at 10:06

• Changed state: Assigned