webp-container-spec: clarify background color note

replace ...a transparency value (alpha)... with clearer text

based on comments from:
https://datatracker.ietf.org/doc/draft-zern-webp/ballot/#draft-zern-webp_lars-eggert

Bug: webp:448
Change-Id: I79157b669c4317ebfc4f8434ee38f2666d1559ec
This commit is contained in:
James Zern 2022-09-29 18:52:20 -07:00
parent 951c292d12
commit 3ed2b27517

View File

@ -400,8 +400,8 @@ Background Color: 32 bits (_uint32_)
**Note**:
* Background color MAY contain a transparency value (alpha), even if the
_Alpha_ flag in [VP8X chunk](#extended_header) is unset.
* Background color MAY contain a non-opaque alpha value, even if the _Alpha_
flag in [VP8X chunk](#extended_header) is unset.
* Viewer applications SHOULD treat the background color value as a hint, and
are not required to use it.