From 585d93dbba5fc2bbb1cfe3ac258a98c65ce917b6 Mon Sep 17 00:00:00 2001 From: Urvang Joshi Date: Wed, 22 Jul 2015 11:55:49 -0700 Subject: [PATCH] Container spec: clarify ordering of ALPH chunk. Reported by user: https://code.google.com/p/webp/issues/detail?id=255 Change-Id: I9c027ea828d5a367b317744fad7607a16ed52fa5 --- doc/webp-container-spec.txt | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/doc/webp-container-spec.txt b/doc/webp-container-spec.txt index 56cff73e..dbb49f14 100644 --- a/doc/webp-container-spec.txt +++ b/doc/webp-container-spec.txt @@ -271,9 +271,15 @@ An extended format file consists of: * An optional list of [unknown chunks](#unknown-chunks). _\[status: experimental\]_ -For a _still image_, the _image data_ consists of a single frame, whereas for -an _animated image_, it consists of multiple frames. More details about frames -can be found in the [Animation](#animation) section. +For a _still image_, the _image data_ consists of a single frame, which is made +up of: + + * An optional [alpha subchunk](#alpha). + + * A [bitstream subchunk](#bitstream-vp8vp8l). + +For an _animated image_, the _image data_ consists of multiple frames. More +details about frames can be found in the [Animation](#animation) section. All chunks SHOULD be placed in the same order as listed above. If a chunk appears in the wrong place, the file is invalid, but readers MAY parse the