4 bits are read ([0, 15]) with 4 added to the result. The check that the
result is not > NUM_CODE_LENGTH_CODES (19) is redundant. This makes the
check an assert for documentation purposes.
webp-lossless-bitstream-spec.txt is updated accordingly.
Bug: webp:611
Change-Id: Ie461017dc9de3da4cfe6856543d3dcf58f53a180
In Section 6.2 Details, use uppercase after a :. This is more consistent
with the rest of the doc.
Bug: webp:611
Change-Id: I7ac862c90fd8e5fe0bad0dd5e3515d3095a6dc9a
in ordered list in "6.2. Details". This is more consistent with the rest
of the document.
Bug: webp:611
Change-Id: Ie467c771afd5813a30855b24c80cf92673a5281c
when referring to the RIFF chunk size; this is more consistent with
other documentation.
Bug: webp:611
Change-Id: Icf05491ee79f5c48fab0b4935da397b4e4e45a71
The serial comma change is based on the Chicago Manual of Style
(CMOS), 17th edition.
Bug: webp:611
Change-Id: Ic02e6652662608414c16e0fead2912781a47633d
Move the details given for meta prefix codes and the transforms from
"5.1. Roles of Image Data" to their corresponding sections.
Bug: webp:611
Change-Id: I750a3f45956d0a3928a22113180a2590ac1a36db
After processing the Color Indexing Transform the image width is
subsampled by the transform's width_bits.
Bug: webp:611
Change-Id: If8d2d47dbe05e5c8085fb3fb4c1b63552be9028b
If ReadBits(0) == 0, the value of max_symbol is set to the alphabet size
for each symbol type.
See vp8l_dec.c, ReadHuffmanCode(), which passes alphabet_size to
ReadHuffmanCodeLengths() as num_symbols, and ReadHuffmanCodeLengths()
then sets max_symbol to that.
Bug: webp:611
Change-Id: I662bd1d7f372e7f2e9c71cc86f87aefd02f36647
Make Entropy Image and Interpretation of Meta Prefix Codes their own
section for ease of reference.
Bug: webp:611
Change-Id: I2dba7b4efd02d8bb250810ebff42ac1687262804
follow up to:
29c9f2d4 webp-lossless-bitstream-spec: minor wording updates
Universally use 'transform' over 'transformation'. The doc generally
uses 'transform' to talk about the individual transforms themselves as
well as their related data.
Bug: webp:611
Change-Id: I097701873bbc440bd399ab5440a914a14f7c62f6
The last use of #decoding-the-code-lengths was removed in:
86f94ee0 Update lossless spec with Huffman codes.
Also remove the redundant section header associated with it.
Bug: webp:611
Change-Id: I7f6bb1a1b75255324f185f4591313d9e6d49d1e9
Remove the ambiguous 'should' which in other contexts might result in
questions as to whether it is a SHOULD or a MUST.
Change-Id: I9b396187ebde5ea5a0dbaf42daee6acf541258cd
Within the 'Entropy image' subsection, its clear this is what is being
described in the following paragraphs. Remove 'as described below' from
the first sentence.
Bug: webp:611
Change-Id: I365d69c8f6963cd826849ebdd96e46206d38b55d
Move this to the top-level of the "Details" section as prefix codes are
discussed in both "Decoding and Building the Prefix Codes" and "Decoding
of Meta Prefix Codes"
Bug: webp:611
Change-Id: Ide2dfedf081d6c94122ac16ecded968ed760f90c
in the Transformations section describing decoding of the transform
data followed by the image data. The section numbers were adjusted by 1
in:
337cf69f webp-lossless-bitstream-spec: mv Nomenclature after Intro
Bug: webp:611
Change-Id: I4eede0d068fabdef51a140a0268436ab6629e8bb
Give some examples of repetition and binary value notation to limit the
need to follow the ABNF reference.
Bug: webp:611
Change-Id: I5b5a7632f011e1523b4a528653fe3630afba3e3e
in 6.2.3 Decoding Entropy-Coded Image Data.
The copying of distance code pixels cause some confusion during the
AUTH48 portion of the RFC review process.
Bug: webp:611
Change-Id: I78f547ae10c95f180355a4c93ec6d48acdc09141
Mostly grammatical and addition/subtraction of commas from the AUTH48
portion of the RFC review process.
The serial comma changes are based on the Chicago Manual of Style
(CMOS), 17th edition.
Bug: webp:611
Change-Id: I5ae2d1cc0196009dbf3a4c2195cc73c2ef809b49
Reference the section by number, rather than 'this section'. Fixes a
lint warning:
Style notice: Write unique, descriptive link text that makes sense
without the surrounding text. Don't use phrases such as this document,
this article, or click here.
https://developers.google.com/style/link-text?hl=en#write-link-text
Change-Id: Iab33e4980528dddb5eed4404d25a4a746705131a
remove AMENDED-notes (the last functional spec change to match with the
implementation is from 2014, other amendments are clarifications)
Bug: webp:581
Change-Id: Ic47739be0fd5a975fd734d6813567ca615304f1d
Have this match simple-prefix-code and redirect to "Normal Code Length
Code" as the added indirection to 'code-length-code' and the undefined
'encoded-code-lengths' doesn't add much.
spotted by thakis@
Change-Id: Icd6b64a47c4e0001e93271d9ae5585be4a6d5906
- add missing '(' in DIV_ROUND_UP
- in 6.2.2, rename 'pos' variable reference to match definition
('position')
spotted by thakis@
Change-Id: Ida3ed281c2c753ebbb0e1eb3c4ed04dadc79ca24
for fixes to the distance_map pseudo-code, the inverse color transform
description and the num_code_lengths check.
Bug: webp:448
Bug: webp:551
Change-Id: Id7e791b97704dd64bb9519657ce48b92cb457ae4
The prose describing the process was missed in:
44dd765d webp-lossless-bitstream-spec: fix ColorTransform impl
Bug: webp:448
Bug: webp:551
Change-Id: If5fb95103ffedeed113e3ad62510f3a19bfd280e
in the 'Normal Code Length Code' description the number of valid code
lengths is 19, not 18.
Bug: webp:448
Bug: webp:551
Change-Id: Id929604e1d771cb09b2d0ac617e83f21077f21de
'zero alpha pixels' was a bit hard to parse; replace this with something
more explicit
Bug: webp:448
Change-Id: Ifc8c93af5520ffdafc58e3fc311dfb4cb19626e9