From 5249e94a225777c5ae06a49eae9fa914bd28bcd6 Mon Sep 17 00:00:00 2001 From: James Zern Date: Tue, 24 Apr 2012 17:43:06 -0700 Subject: [PATCH] doc: tile/alpha corrections - the tile chunk size does not include the alpha or vp8 chunks that follow - remove 'experimental' note from alpha section - drop an unused term from the terminology section Change-Id: I46f0fd610bbce579446e19339c3458dddfb595f7 --- doc/webp-container-spec.txt | 16 ++-------------- 1 file changed, 2 insertions(+), 14 deletions(-) diff --git a/doc/webp-container-spec.txt b/doc/webp-container-spec.txt index 9be9930f..2fe1c6ab 100644 --- a/doc/webp-container-spec.txt +++ b/doc/webp-container-spec.txt @@ -121,10 +121,6 @@ _ChunkHeader('ABCD')_ chunks, where 'ABCD' is the fourcc for the chunk. This element's size is 8 bytes. -_chunk of type_ - -: A chunk with a tag "ABCD". - : Note that, in this specification, all chunk tag characters are in file order, not in byte order of a uint32 of any particular architecture. @@ -413,8 +409,6 @@ Notes for frames containing VP8 data: +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Tile Canvas Y | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Tile Data | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Tile Canvas X: 32 bits (_uint32_) @@ -424,12 +418,8 @@ Tile Canvas Y: 32 bits (_uint32_) : Y coordinate of the upper left corner of the tile. -Tile Data: _Chunk Size_ - `8` bytes - -: VP8 data. - This chunk contains information about a single tile and describes the -bitstream chunk that follows it. +(optional) alpha chunk and bitstream chunk that follows it. Notes for tiles containing VP8 data: @@ -486,9 +476,7 @@ Either **ALL or NONE** of the tiles must contain this chunk. The alpha channel can be encoded either losslessly or with lossy preprocessing (quantization). After the optional preprocessing, the alpha values are encoded with a lossless compression method like -zlib. Work is in progress to improve the compression gain further by -exploring alternate compression methods and hence, the bitstream for -the Alpha-chunk is still experimental and expected to change. +zlib. #### Color profile