From 2c1f833a092ef7af17f072749940bcb47da19aa6 Mon Sep 17 00:00:00 2001 From: wolfbeast Date: Mon, 24 Jul 2017 13:19:25 +0200 Subject: Add libwebp 0.6.0 to the tree --- media/libwebp/utils/random_utils.c | 43 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100644 media/libwebp/utils/random_utils.c (limited to 'media/libwebp/utils/random_utils.c') diff --git a/media/libwebp/utils/random_utils.c b/media/libwebp/utils/random_utils.c new file mode 100644 index 000000000..9f1e4154a --- /dev/null +++ b/media/libwebp/utils/random_utils.c @@ -0,0 +1,43 @@ +// Copyright 2013 Google Inc. All Rights Reserved. +// +// Use of this source code is governed by a BSD-style license +// that can be found in the COPYING file in the root of the source +// tree. An additional intellectual property rights grant can be found +// in the file PATENTS. All contributing project authors may +// be found in the AUTHORS file in the root of the source tree. +// ----------------------------------------------------------------------------- +// +// Pseudo-random utilities +// +// Author: Skal (pascal.massimino@gmail.com) + +#include +#include "./random_utils.h" + +//------------------------------------------------------------------------------ + +// 31b-range values +static const uint32_t kRandomTable[VP8_RANDOM_TABLE_SIZE] = { + 0x0de15230, 0x03b31886, 0x775faccb, 0x1c88626a, 0x68385c55, 0x14b3b828, + 0x4a85fef8, 0x49ddb84b, 0x64fcf397, 0x5c550289, 0x4a290000, 0x0d7ec1da, + 0x5940b7ab, 0x5492577d, 0x4e19ca72, 0x38d38c69, 0x0c01ee65, 0x32a1755f, + 0x5437f652, 0x5abb2c32, 0x0faa57b1, 0x73f533e7, 0x685feeda, 0x7563cce2, + 0x6e990e83, 0x4730a7ed, 0x4fc0d9c6, 0x496b153c, 0x4f1403fa, 0x541afb0c, + 0x73990b32, 0x26d7cb1c, 0x6fcc3706, 0x2cbb77d8, 0x75762f2a, 0x6425ccdd, + 0x24b35461, 0x0a7d8715, 0x220414a8, 0x141ebf67, 0x56b41583, 0x73e502e3, + 0x44cab16f, 0x28264d42, 0x73baaefb, 0x0a50ebed, 0x1d6ab6fb, 0x0d3ad40b, + 0x35db3b68, 0x2b081e83, 0x77ce6b95, 0x5181e5f0, 0x78853bbc, 0x009f9494, + 0x27e5ed3c +}; + +void VP8InitRandom(VP8Random* const rg, float dithering) { + memcpy(rg->tab_, kRandomTable, sizeof(rg->tab_)); + rg->index1_ = 0; + rg->index2_ = 31; + rg->amp_ = (dithering < 0.0) ? 0 + : (dithering > 1.0) ? (1 << VP8_RANDOM_DITHER_FIX) + : (uint32_t)((1 << VP8_RANDOM_DITHER_FIX) * dithering); +} + +//------------------------------------------------------------------------------ + -- cgit v1.2.3