Commit Graph

67 Commits

Author SHA1 Message Date
Urvang Joshi
d5bad03328 Animated WebP: add "do no blend" option to spec
Marking certain frames as "do not blend" helps avoiding alpha-blending
at decode/render time.

It also helps inserting I-frames (frames which can be independently
decoded) into the animation.

Change-Id: Iaa222805db88d2f1c81104ce9d882e7c7ff8cfdb
2013-08-14 11:50:15 -07:00
Lou Quillio
c606182edd webp-container-spec: Tighten language added by last
Change-Id: Id7719ba7f1ddfd7b54a1985771b2811318a7c0d7
2013-07-09 18:45:39 -07:00
Urvang Joshi
5e9675329c Container spec: a clarification on background color.
Change-Id: Ifeb565bd162abfa03dfcbf8b576657fe83956a6c
2013-06-20 17:38:08 -07:00
Urvang Joshi
403bfe820c Container spec: Clarify frame disposal
- Add a note that disposal only applies to the frame rectangle
- Add the formula for alpha-blending.
- Note that alpha-blending would occur for the common rectangle
- Also note the case when both color profile and disposal are
present.

Change-Id: I214787dd64453edf3b0cdaff3951015281a32ee4
2013-03-29 11:42:17 -07:00
James Zern
3e7a13a008 Merge "Container spec: clarify the background color field" into 0.3.0 2013-03-26 17:38:07 -07:00
James Zern
14af77452b container doc: add a note about the 'ANMF' payload
this consists of padded chunks, so ANMF should require none

Change-Id: I5dff623b56d8a466dc9be03ee87d1d2d19efc088
2013-03-26 17:25:27 -07:00
Urvang Joshi
cc635efa01 Container spec: clarify the background color field
Change-Id: I03f634cbd147c2851eb06ddbc7b1014e04e21038
2013-03-26 17:22:18 -07:00
James Zern
e3e339497e container doc: move RIFF description to own section
- remove some little used terms
- condense file header description
- add description of FourCC

Change-Id: Ia873652f41789811f3fb2ec97182a068ac727961
2013-03-26 17:16:12 -07:00
Urvang Joshi
d1e21b13b7 Remove 'status: experimental' from container spec
For features that are to be released in v0.3.0.

Change-Id: Ib8961f8cde0474aeaad5796bd0821db812edffcd
2013-03-13 18:16:30 -07:00
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
Urvang Joshi
6523e2d41d WebP Container:
annotate specific sections as experimental

Change-Id: If43222cef1c4fc2a8164b5f6ca4e89033379757d
2012-11-15 11:01:41 -08:00
Urvang Joshi
a7305c2ef0 Clarification for unknown chunks
clarify that writers *may* modify unknown chunks if they specifically
intend to do so.

Change-Id: I8348df2ec84648201ea781c7bfffd1f36eb3c8e5
2012-11-13 10:41:13 -08:00
Urvang Joshi
4c4398e2d5 Refine WebP Container Spec wrt unknown chunks.
Change-Id: Ibe950ab7afb2a7349f61c6fb81d587fba9ff27b6
2012-11-12 14:32:44 -08:00
Urvang Joshi
52ad1979d2 Animation specification in container spec
Change-Id: I3cb1d994a460d9a712998ca1045bf6bc7d953c04
2012-11-05 13:29:23 -08:00
Urvang Joshi
001b930219 Image fragment specification in container spec
Change-Id: If8cad296738465df4327dfb6b44efa7e0356070e
2012-11-02 15:37:49 -07:00
Urvang Joshi
391f9db9fa Ordering of description of bits in container spec
The description of bits in a byte should be from MSB to LSB

Change-Id: I50f2dfbb79b33eb434a771cca252c5d0f81fc71e
2012-11-02 15:27:37 -07:00
Urvang Joshi
d57357762a Metadata specification in container spec
Change-Id: I4b76697efb160145ffef3fd9df9905544c4e8792
2012-11-02 15:14:47 -07:00
Urvang Joshi
af6f0db291 Color profile specification in container spec
Change-Id: I53f849c7d93e1cdc971dda1fffd8f359f40607d3
2012-11-01 11:16:29 -07:00
Jyrki Alakuijala
d03b250369 fixing the findings by Frederic Kayser to the bitstream spec
Change-Id: I4bcc428412dd4c21675d90159771e2e0b338ecf3
2012-07-18 22:47:11 -07:00
Lou Quillio
4e2e0a8cac Doc: container spec text tweaks
Change-Id: I8e29f1c814b0c8f6aa268562d8653989caaf281d
modified:   doc/webp-container-spec.txt
2012-07-18 16:38:50 -07:00
James Zern
6431a1ce3d doc: remove non-finalized chunk references
tiles, animation, etc.

Change-Id: Ie83135be576f516fe475c7be21171f9d12a17ce4
2012-07-13 12:33:49 -07:00
James Zern
85bff2cdbe Merge "doc: correct lossless prefix coding table & code" 2012-07-13 11:12:14 -07:00
James Zern
20ead3290f doc/webp-container-spec: light cosmetics
- provide anchor links to the bitstream chunks referenced in the
  extended format section
- remove some unnecessary parenthetical notation and add some
  consistency to various chunk element definitions

Change-Id: Ifd946fee81b36e4e555399555a2a58c853fdc3b7
2012-07-12 19:19:39 -07:00
pascal massimino
45b8272c31 Merge "restore authorship to lossless bitstream doc" 2012-07-11 13:56:10 -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
Pascal Massimino
44a09a3ccd add missing description of the alpha filtering methods
Change-Id: Id7bdf5e30121ce5d610b7fa00f64bcd2d7bed2bf
2012-07-10 19:50:30 -07:00
Urvang Joshi
135ca69eb7 WebP Container Spec:
Clarify that a file must contain at least one frame.

Change-Id: I7ecc97084498adc108275585d0c7d0aaa9f5c6ed
2012-07-04 17:28:17 +05:30
Pascal Massimino
7f22bd2596 check limit of width * height is 32 bits
Update the RIFF-specs file too

Change-Id: I113a7e25da2f7a19c1344c1dc5d496127cfe2596
2012-07-03 05:42:13 -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
Urvang Joshi
97649c8f6b Mux: Allow only some frames/tiles to have alpha.
And related const fixes.

Change-Id: I79f6f1b9f8c6faac8cc4ef24b58edff6d90de045
2012-06-29 17:17:19 +05:30
James Zern
c963482124 doc: remove lossless pdf
superseded by webp-lossless-bitstream-spec.txt

Change-Id: I5f233d4c3c2fa048a180db950ad4319ffdb9bced
2012-06-22 15:25:03 -07:00
Urvang Joshi
7f8472a610 Update the WebP Container Spec.
- Add details about the VP8L chunk support.
- Also add new example bitsteams containing VP8L chunk.
- Add back a section describing the VP8 chunk.
- Restrict some fields to 16 or 24 bits instead of 32 bits.
- Fields whose values are always positive are stored 1-based
instead of 0-based.
- Unknown chunks can only occur at certain places in the file.
- Remove the restriction for some fields to be divisible by 32 or 16.
  Instead they are restricted to be even.
- Add a restriction for (canvas_width * canvas_height) product.
- Add 3 bits for rotation & symmetry in VP8X flags.
- Add some new example layouts.
- Add/clarify some nitty-gritties throughout the doc.
- Use the terms frame/tile more consistently and logically.
- Update related TODOs.

Change-Id: I611c1f58ecc3ee87546ca31bad1609376fad251e
2012-06-21 16:04:58 -07:00
Lou Quillio
b7ac19fec9 Add kramdown version information to README
Example kramdown command line to apply syntax highlighting requires
kramdown latest. Command is slightly different for earlier versions.

modified:   doc/README

Change-Id: Icda1197436b5c5ed936ceff53c1dc51aa4ce409b
2012-06-20 14:17:36 -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
James Zern
0ca170c2dd doc: update lossless pdf
Change-Id: I8c6d0e6fc21196f6dd239b21eda2097ba4ce2bba
2012-06-04 16:53:16 -07:00
Pascal Massimino
0862ac6e7e add a PDF of the lossless spec
(cherry picked from commit db9967748781d73832b3875db1dfcbefb180f7c9)

Change-Id: I5909abc48d9b4c4415f81a019681968f06d6a3d7
2012-06-04 16:51:39 -07:00