Commit Graph

8 Commits

Author SHA1 Message Date
Pascal Massimino
ab2dc8939f Rescaler: fix rounding error
We saturate the result to [0..255]
It's the easiest and safest, given the wide variety of scaling
range we cover: we're not using floats, so precision is always
an issue at one end or the other of the scaling spectrum.

we also use:
  round(a - floor(b))
instead of:
  floor(a - round(b))
to handle difficult cases (ratio ~= .99, e.g.)

MIPS code is still disabled (and wrong)

Change-Id: I18d3f5ddc4c524879c257b928329b1c648fa7fb5
2019-03-30 06:43:55 +00:00
Pascal Massimino
2563db4759 fix rescaling rounding inaccuracy
We should be using 'floor' when doing the final divide.

-> new MACRO is MULT_FIX_FLOOR()

     XXX*** Mips code is DISABLED for now ***XXX

I'll update and re-enable it in a later
patch, since this code needs some refactoring first.

BUG=oss-fuzz:9179

Change-Id: Ic0693cdca4e71f5beab1029475e35c4d06b12d13
2018-07-10 22:45:50 -07:00
Pascal Massimino
0df22b9eed WEBP_REDUCE_SIZE: disable all rescaler code
BUG=webp:355

Change-Id: Id87cb11902e3fb8544a214308526ea9665ce8440
2017-11-24 22:08:32 +00:00
James Zern
ab9c2500db rescaler_neon: harmonize function suffixes
BUG=webp:355

Change-Id: I161caa14f7ebbc3ae978b1722472625a77d0a4a4
2017-10-20 19:00:53 -07:00
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
skal
c4568b47fd Rescaler: harmonize the suffix naming
BUG=webp:355

Change-Id: I7720502c62f96c780793d3d881eac7b3afae1418
2017-08-01 23:49:44 +00:00
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
skal
b4e731cd93 neon-implementation for rescaler code
It's better to stay with a 32b fixed-point precision overall, otherwise
the C-version on ARM gets *slower*.
Actually, gcc ARM compiler optimizes some instructions pretty
well when WEBP_RESCALER_FIX is exactly 32, even in C.

Change-Id: I0eea97f7db5947470f5af355dee098eca81e178d
2015-10-07 21:18:39 -07:00