14 Commits

Author SHA1 Message Date
James Zern
b9d2f9cd3b quant_enc.c: use WEBP_RESTRICT qualifier
results in code layout changes, a couple fewer instructions; some of the
smaller functions were unaffected as they were inlined, but are updated
for consistency. this mostly affects VP8Decimate(), ReconstructIntra16()
and ReconstructUV().

Change-Id: Icc2582278987a66ad1110bab683d1e0c21e6591a
2022-02-10 11:07:18 -08:00
Vincent Rabaud
1a8f0d45d3 Have a hard-coded value for memset in TrellisQuantizeBlock.
Change-Id: I1b842bb0cfec9e8559d0f11b3db8fa1bc1c9692f
2021-08-30 18:50:11 +02:00
Vincent Rabaud
934801604e Speed up TrellisQuantizeBlock
- only initialize variable when needed
- perform first loop outside the for loop
- perform computation only if know we are not already worse
- not adding base_score every time

Change-Id: I2cb8231fcaec1113b5902ed61b685f0ae3c78823
2021-08-30 17:07:42 +02:00
Pascal Massimino
9d6988f44d Fix the oscillating prediction problem at low quality
For some exact resonance the over-quantization was exactly
compensating the under-quantization, leading to resonance
and strange patterns.

-> we special-handle the very flat blocks, hopefully for the
greater good (and not just the bad-resonance case).

For 'fast mode' (-m 3 or less), we just pay special attention
to the border of the image, where the oscillation / instability
usually starts. For the inner part of the image, since we're not
doing rd-opt, it's harder to fix anything.

Overall, on 'regular' images, the change is written the noise,
often leading to overall faster encoding (because of the short-cut).

BUG=webp:432

Change-Id: Ifaa8286499add80fd77daecf8e347abbff7c3a15
2019-07-03 08:40:41 -07:00
Johann
5173d4ee6f neon IsFlat
Move IsFlat to its own header. This allows it to continue to be
inlined. Using the RTCD and creating a distinct function slows down arm
builds.

   flower   mug
C    3.59  2.12
NEON 3.47  2.01

BUG=b/118740850

Change-Id: Id77e8f76d9e9790c498806e7070bbe37c10bc2e9
2018-12-03 22:59:12 +00:00
Johann
5b081219c9 IsFlat: inline when possible
Change-Id: Ia7471d29f73233cdc58cd11ae8bdf7ce31b9ce9f
2018-11-29 14:37:29 -08:00
Johann
381b7b54a0 IsFlat: use int for thresh
thresh is defined by FLATNESS_LIMIT_* which ranges from 2-10.

score_t is int64 which is a touch overkill.

Change-Id: I308bd440bf11643665d3642fe361495a257b6e52
2018-11-29 14:34:17 -08:00
Johann
f435de9575 IsFlat: return int
IsFlat is a boolean function. Don't use a specialized return type.

Change-Id: I070395082023ceb50251c44f5f4253b90394710c
2018-11-16 11:22:41 -05:00
Pascal Massimino
815652de03 enable dc error-diffusion always
for q<=98, we always enable error diffusion.

+ reduce storage 2x by using int8_t
+ make the error diffusion more robust

BUG=webp:340,308

Change-Id: I0608df839ff7b64d6843005a0f81d2577143af9e
2017-12-27 20:11:57 +00:00
Pascal Massimino
96bf07c560 use DC error diffusion for U/V at low-quality
This fixes some color smearing due to heavy quantization.
This is only enabled for q <= 30 (cf ERROR_DIFFUSION_QUALITY)

Change-Id: I07e83a4d38461357a32c9e214f7eadc6db73baa9
2017-12-11 06:37:40 -08:00
James Zern
083507f244 right-size some tables
Change-Id: I5e894fd3f0f4b666512108495d8cecb34f65e119
2017-11-23 08:40:58 +00:00
James Zern
a439972175 WIP: list includes as descendants of the project dir
#include "(.|..)/..." -> #include "src/..."

Change-Id: I772880aa097a770722043c8a4393552ba38a89b6
2017-10-10 23:04:05 -07:00
Vincent Rabaud
3993af127e Fix signed integer overflows.
Change-Id: I62c9949f0edac58d69d991d6be5f85ae9e4d62a9
2017-08-31 11:56:42 +02:00
James Zern
668e1dd44f src/{dec,enc,utils}: give filenames a unique suffix
this avoids duplicates between these trees and dsp/, e.g., enc/tree.c,
dec/tree.c, making pulling the whole library source tree into one target
possible

BUG=webp:279

Change-Id: I060a614833c7c24ddd37bf641702ae6a5eef1775
2017-01-19 19:09:48 -08:00