Commit Graph

22 Commits

Author SHA1 Message Date
Pascal Massimino
13ae011e4c doc: use two's complement explicitly for uint8->int8 conversion
BUG=webp:225

Change-Id: I6bad131e275dbd992484e95a1b834010121281b8
2016-09-05 10:57:56 -07:00
Pascal Massimino
d7167ff7ce Amend the lossless spec according to issue #205, #206 and #224
http://code.google.com/p/webp/issues/detail?id=205 <- Select()
http://code.google.com/p/webp/issues/detail?id=206 <- out-of-bound colormap index
http://code.google.com/p/webp/issues/detail?id=224 <- version number MUST be 0

Change-Id: I56a575529862dfc8ad189ddcfc47ef59a58f273d
2014-09-18 08:21:02 +02:00
Urvang Joshi
8425aaee8f Formatting fixes in lossless bitstream spec
- Escape brackets for which kramdown was generating a warning.
Note: This only changes this source file; output HTML would look exactly
the same.
- Also write '5' in words ('five').

Change-Id: I472a03c090a12eb7520719ea463469b36a2736b9
2013-01-18 14:35:47 -08:00
Urvang Joshi
f01c2a538c WebP-lossless spec clarifications:
- Clarify the BNF using 'Huffman code groups' and 'Huffman code group'.
- Introduce same terminology in 'Interpretation of meta Huffman codes'.
- Make explicit mention of what is the number of Huffman code groups,
  number of Huffman codes and the relation between the two.

Change-Id: I07aa9b62c1d464cd25dc02ac1a68d338b575bdc2
2013-01-17 15:19:09 -08:00
Urvang Joshi
1f075f89b0 Lossless spec corrections/rewording/clarifications
- Correct BNF for 'predictor-image' and 'color image'
- Correct some references to 'br', 'VP8LReadBits' and 'ReadStream'
- Correct value ranges in distance mapping table.
- Rewrite section 4 (some rearrangement, rewording, adding context etc).
- Similarly, rewrite section 5.

Change-Id: If487490c2553b3f7982b9fcca68d98bab5017e3c
2012-12-20 10:44:42 -08:00
Urvang Joshi
d82a3e3391 More corrections/clarifications in lossless spec:
- Rectify a few BNF descriptions
- Corrections in "Decoding Flow of Image Data" section:
  1. The sequence in case of "S < 256" should be green, red, blue, alpha.
  2. In case of "S >= 256 + 24", the index should be "S - (256 + 24)".
- Provide more description to clarify "Decoding Flow of Image Data" section.
- Some cosmetics: use '1's instead of '1, 2, 3...' sequence, as kramdown takes
  care of sequencing.

Change-Id: I2b76caf72f67aae813522dc1a4115f8ec8ea6db7
2012-12-17 11:40:23 -08:00
Urvang Joshi
bcec339b01 Lossless bitstream clarification:
Clarify what the pixels of a color transform image are.

Change-Id: I720248b5417857468d54952440cf1bae6c091042
2012-12-12 14:03:44 -08:00
Urvang Joshi
931bd516b8 lossless bitstream: block size bits correction
The color transform block size is stored as 3 bits, not 4.
Fixed the description. The code snippet is already correct.

Change-Id: I830d848b54c121cb5426ca06853a3f1184fd9a31
2012-12-05 13:38:05 -08:00
Pascal Massimino
e4fc4c1c63 lossless bitstream: block size bits correction
The prediction block size is stored as 3 bits, not 4.
Fixed the description. The code snippet is already correct.

Change-Id: Iaa66a7e9817b58a2557c9a71c2231cc400b6ae4d
2012-12-05 00:01:28 -08:00
Jyrki Alakuijala
d03b250369 fixing the findings by Frederic Kayser to the bitstream spec
Change-Id: I4bcc428412dd4c21675d90159771e2e0b338ecf3
2012-07-18 22:47:11 -07:00
James Zern
85bff2cdbe Merge "doc: correct lossless prefix coding table & code" 2012-07-13 11:12:14 -07:00
James Zern
06ba05909e restore authorship to lossless bitstream doc
lost in port from pdf

Change-Id: I17bad348577be9818c036e557a0beba63ffcc689
2012-07-11 13:46:00 -07:00
James Zern
61c9d161d5 doc: correct lossless prefix coding table & code
extra bit counts and literal distance return value

Change-Id: I290e3ee8900469503a323f87e9dbb8ca5cb4afc7
2012-07-01 14:10:32 -07:00
Lou Quillio
04e33f17de Edit for consistency, usage and grammar.
Substantial edit, though less than 100% thorough.  This
makes changes that are clearly safe, but avoids others
where my domain knowledge is incomplete and accuracy
might be compromised.

modified:   doc/webp-lossless-bitstream-spec.txt

Change-Id: I89361a2e1157b8d2e44a8b4f4603f65833f0c1e6
2012-06-20 10:08:53 -07:00
Lou Quillio
9aa34b3438 Manually number "chapters," as chapter numbers are used in the narrative.
modified:   doc/webp-lossless-bitstream-spec.txt

Change-Id: Ice662960ff988a6ff577a8ca5a594e14ba69d4de
2012-06-15 14:54:19 -07:00
Lou Quillio
2a4c6c29a0 Re-wrap at <= 72 columns
modified:   doc/webp-lossless-bitstream-spec.txt

Change-Id: Ie8d7aa907dc20d941b74455f8657d4e1b4e23bbb
2012-06-15 14:54:13 -07:00
Lou Quillio
a45adc1918 Apply inline emphasis and monospacing, per gdoc / PDF
modified:   doc/webp-lossless-bitstream-spec.txt

Change-Id: I2d996d5e80967641e22997d4f6e7173b39df0978
2012-06-15 14:54:06 -07:00
Lou Quillio
91011206ad Incorporate gdoc changes through 2012-06-08
modified:   doc/webp-lossless-bitstream-spec.txt

Change-Id: I01c04772bff7e3d7d6f0b526949cd846b5a97c8d
2012-06-15 14:53:55 -07:00
Lou Quillio
7a18248716 Removed CodeRay syntax declarations ...
... as they became unnecessary when upstream (kramdown)
implemented LQ feature request:
17625c8082

Also updated (and simplified) syntax-highlighting instructions.

modified:   doc/README
modified:   doc/webp-lossless-bitstream-spec.txt
Change-Id: I6f02b0d0a69a4d1d96cb0f771936cbe9e2e6bbec
2012-06-15 14:53:39 -07:00
Lou Quillio
b3ec18c556 Provide for code-block syntax highlighting.
modified:   doc/README
modified:   doc/webp-lossless-bitstream-spec.txt

Change-Id: I5cbc9c0a4fbbcc049a4d792e1fac367d28acf4a6
2012-06-15 14:53:29 -07:00
Lou Quillio
709d770241 Replace high ASCII artifacts (curly quotes, etc.).
modified:   doc/webp-lossless-bitstream-spec.txt
Change-Id: I9dd9d4ed05c8f93d4cafadf8c99cc21c300a9299
2012-06-15 14:53:16 -07:00
Lou Quillio
930e8abbda Lossless WebP doc largely ported to markdown text.
Word-level formatting (italics, bold) remains to be done,
but awaits final author edits, to avoid rework.

modified:   doc/template.html
new file:   doc/webp-lossless-bitstream-spec.txt

Change-Id: Id684d2a10d02e197d660a960540fe83f87d317f2
2012-06-15 14:52:57 -07:00