20 Commits

Author SHA1 Message Date
James Zern
4f7f52b2a1 VP8LFillBitWindow: respect WEBP_FORCE_ALIGNED
Change-Id: I23eddf01590de002efc21d8c7acc545a08fc3e48
2014-07-04 13:53:29 -07:00
Pascal Massimino
09545eeadc lossy bit-reader clean-up:
* remove LEFT/RIGHT_JUSTIFY distinction. It's all RIGHT_JUSTIFY now.
* simplify VP8GetSigned(), and add some masking branch-less code. Much
  faster on ARM (~13% speed-up). 8% on x86-64, 5% on MacBook.
* split critical implementation into separate bit_reader_inl.h file that
  is only included where needed (vp8.c / tree.c / bit_reader.c)
* bumped BITS value from 16 to 24 for x86-32b too, since it's a bit faster.

Change-Id: If41ca1da3e5c3dadacf2379d1ba419b151e7fce8
2014-06-03 07:46:55 +02:00
Pascal Massimino
fdbcd44dd3 simplify VP8LInitBitReader()
gcc was generating very complex code, one for each case of br->len_ values!

also, pretty-fy the mask constants

Change-Id: If62b1e8266f3fe5334517305113038d2ea8a6b42
2014-05-22 21:44:16 -07:00
skal
176fda2650 fix the bit-writer for lossless in 32bit mode
Sometimes, we can write 18bit or more at time, and it would
overflow the 32bit accumulator.

Also clarified the num-bits limitations (and exposed
VP8L_MAX_NUM_BIT_READ in bit_reader.h)

fixes http://code.google.com/p/webp/issues/detail?id=200

Seems a bit faster (use of local fields for bits_ / used_)

also: added the __QNX__ bswap while at it.

Change-Id: I876db93a931db15b083cf1d838c70105effa7167
2014-05-22 07:19:22 +02:00
skal
54bfffcabc move RemapBitReader() from idec.c to bit_reader code
mostly for coherency and later patch.

Change-Id: Ica8352d67845b6c5b3153435edfb4646c6f24341
2014-05-14 07:07:08 +02:00
Urvang Joshi
8c7cd722f6 Bugfix: Incremental decode of lossy-alpha
When remapping buffer, br->eos_ was wrongly being set to true for
certain
images.

Also, refactored the end-of-stream detection as a function.

Reported in http://crbug.com/364830

Change-Id: I716ce082ef2b505fe24246b9c14912d8e97b5d84
2014-04-22 16:06:32 -07:00
James Zern
5227d99146 drop: ifdef __cplusplus checks from C files
the prototypes are already marked in the headers

Change-Id: I172fe742200c939ca32a70a2299809b8baf9b094
2013-12-13 11:42:13 -08:00
Urvang Joshi
96ad0e0aef VPLBitReader bugfix: Catch error if bit_pos > LBITS too.
Earlier we were only testing for bit_pos == LBITS. But this is not
sufficient,
as bit_pos can jump from < LBITS to > LBITS.

This was resulting in some bit-stream truncation errors not being
caught.

Note: Not a security bug though, as br->pos wasn't incremented in such
cases
and so we weren't reading beyond the buffer.

Change-Id: Idadcdcbc6a5713f8fac3470f907fa37a63074836
2013-10-30 16:33:36 -07:00
James Zern
d640614d54 update copyright text
rather than symlink the webm/vpx terms, use the same header as libvpx to
reference in-tree files

based on the discussion in:
https://codereview.chromium.org/12771026/

Change-Id: Ia3067ecddefaa7ee01550136e00f7b3f086d4af4
2013-06-06 23:09:14 -07:00
skal
1667bded67 Remove ReadOneBit() and ReadSymbolUnsafe()
Simplify and re-organize the VP8L bit-reader functions
(e.g.: the 40-bit look-ahead code was helping much)

Speed-up with LBITS=64, on arm7-a:

=> before:
./dwebp_justify_24_neon -v bryce_ll.webp
Time to decode picture: 11.393s
File bryce_ll.webp can be decoded (dimensions: 11158 x 2156).
...

=> after (LBITS=64):	Time to decode picture: 9.953s

making the VP8L bit-reader in 32 bit mode is going to be
harder (because we need to be able to read two symbols
at a time, each with max length 15 bits)

Change-Id: I89746fb103b87b5e2fd40a3208a6fbc584b88297
2013-02-20 00:13:23 +01:00
skal
3383885799 faster decoding (3%-6%)
. revamped the boolean decoder to use less shifts
. added some description and ASCII art as explanations too.
. clarified the types further (bit_t, lbit_t, range_t, etc.)
. changed the negative field 'missing_' into positive 'bits_'

Some stats, decoding some randomly encoded WebP files:

with USE_RIGHT_JUSTIFY:
  BITS=32 => 133 files, 50 loops => 7.3s (1.097 ms/file/iterations)
  BITS=24 => 133 files, 50 loops => 7.3s (1.097 ms/file/iterations)
  BITS=16 => 133 files, 50 loops => 7.4s (1.120 ms/file/iterations)
  BITS=8 => 133 files, 50 loops => 7.5s (1.128 ms/file/iterations)

without USE_RIGHT_JUSTIFY:
  BITS=32 => 133 files, 50 loops => 7.5s (1.131 ms/file/iterations)
  BITS=24 => 133 files, 50 loops => 7.6s (1.142 ms/file/iterations)
  BITS=16 => 133 files, 50 loops => 7.6s (1.143 ms/file/iterations)
  BITS=8 => 133 files, 50 loops => 7.6s (1.149 ms/file/iterations)

Change-Id: I9277fb051676c05582e9c7ea3cb5a4b2a3ffb12e
2013-02-14 15:42:58 +01:00
Pascal Massimino
6920c71f0a fix MSVC warnings regarding implicit uint64 to uint32 conversions
Change-Id: I284dae9222a3817bba3c5ba6be271b31b5bf660d
2012-09-01 07:21:45 -07:00
James Zern
596dff784d VP8LFillBitWindow: use 64-bit path for msvc x64 builds
Change-Id: I14a3865f4091dd048e02abc99aa4e7f1e325e12a
2012-07-14 13:20:26 -07:00
Pascal Massimino
48b39eb17a fix underflow for very short bitstreams
+ hardened the asserts

Change-Id: Ie798ef2f9d848c131f6f84a35ea28ef254822d1e
2012-07-09 16:47:34 -07:00
Pascal Massimino
fac0f12e1b rename BitReader to VP8LBitReader
Change-Id: I192b76422e131a94fb58c2c4a5520a5dba807126
2012-04-13 01:56:31 -07:00
Pascal Massimino
6f01b830e2 split the VP8 and VP8L decoding properly
* each with their own decoder instances.
* Refactor the incremental buffer-update code a lot.
* remove br_offset_ for VP8LDecoder along the way
* make VP8GetHeaders() be used only for VP8, not VP8L bitstream
* remove VP8LInitDecoder()
* rename VP8LBitReaderResize() to VP8LBitReaderSetBuffer()
(cherry picked from commit 5529a2e6d47212a721ca4ab003215f97bd88ebb4)

Change-Id: I58f0b8abe1ef31c8b0e1a6175d2d86b863793ead
2012-04-10 23:06:58 -07:00
James Zern
c4ae53c8b3 add utils/bit_reader.[hc] changes from experimental
Pulled from the parent of the current version (5529a2e^).
The history of this and related files is a bit entangled so rather
trying to split the changes and introduce some noise in master's history
we'll start with a fresh snapshot.
The file progression is still available in the experimental branch.

Change-Id: I6dae97fc381cd6c1d1640c4c565b2084a41ec955
2012-04-10 17:48:49 -07:00
Pascal Massimino
01b6380656 4-5% faster decoding, optimized byte loads in arithmetic decoder.
Bits are loaded 32bits at a time (and often aligned).
Rather 64bit-friendly

Change-Id: If7f67dbe5e37696efbeb6d579d9d8482350b79ee
2012-01-31 02:07:15 -08:00
James Zern
ad1e163a0d cosmetics: normalize copyright headers
Change-Id: I5e2462b101e0447a4f15a1455c07131bc97a52dd
2012-01-06 14:49:06 -08:00
Pascal Massimino
b112e83647 create a libwebputils under src/utils
with bit_reader bit_writer and thread for now.

Change-Id: If961933fcfc43e60220913fe4d527230ba8f46bb
2011-09-13 15:34:15 -07:00