From 5545a8983ff0ef1fb52e64aef8e66fa9b13c1cbb Mon Sep 17 00:00:00 2001 From: "Matt A. Tobin" Date: Tue, 7 Apr 2020 23:30:51 -0400 Subject: Move aom source to a sub-directory under media/libaom There is no damned reason to treat this differently than any other media lib given its license and there never was. --- media/libaom/src/aom_dsp/add_noise.c | 73 ++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 media/libaom/src/aom_dsp/add_noise.c (limited to 'media/libaom/src/aom_dsp/add_noise.c') diff --git a/media/libaom/src/aom_dsp/add_noise.c b/media/libaom/src/aom_dsp/add_noise.c new file mode 100644 index 000000000..bfb3e7e00 --- /dev/null +++ b/media/libaom/src/aom_dsp/add_noise.c @@ -0,0 +1,73 @@ +/* + * Copyright (c) 2016, Alliance for Open Media. All rights reserved + * + * This source code is subject to the terms of the BSD 2 Clause License and + * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License + * was not distributed with this source code in the LICENSE file, you can + * obtain it at www.aomedia.org/license/software. If the Alliance for Open + * Media Patent License 1.0 was not distributed with this source code in the + * PATENTS file, you can obtain it at www.aomedia.org/license/patent. + */ + +#include +#include + +#include "config/aom_config.h" +#include "config/aom_dsp_rtcd.h" + +#include "aom/aom_integer.h" +#include "aom_ports/mem.h" + +void aom_plane_add_noise_c(uint8_t *start, char *noise, char blackclamp[16], + char whiteclamp[16], char bothclamp[16], + unsigned int width, unsigned int height, int pitch) { + unsigned int i, j; + + for (i = 0; i < height; ++i) { + uint8_t *pos = start + i * pitch; + char *ref = (char *)(noise + (rand() & 0xff)); // NOLINT + + for (j = 0; j < width; ++j) { + int v = pos[j]; + + v = clamp(v - blackclamp[0], 0, 255); + v = clamp(v + bothclamp[0], 0, 255); + v = clamp(v - whiteclamp[0], 0, 255); + + pos[j] = v + ref[j]; + } + } +} + +static double gaussian(double sigma, double mu, double x) { + return 1 / (sigma * sqrt(2.0 * 3.14159265)) * + (exp(-(x - mu) * (x - mu) / (2 * sigma * sigma))); +} + +int aom_setup_noise(double sigma, int size, char *noise) { + char char_dist[256]; + int next = 0, i, j; + + // set up a 256 entry lookup that matches gaussian distribution + for (i = -32; i < 32; ++i) { + const int a_i = (int)(0.5 + 256 * gaussian(sigma, 0, i)); + if (a_i) { + for (j = 0; j < a_i; ++j) { + char_dist[next + j] = (char)i; + } + next = next + j; + } + } + + // Rounding error - might mean we have less than 256. + for (; next < 256; ++next) { + char_dist[next] = 0; + } + + for (i = 0; i < size; ++i) { + noise[i] = char_dist[rand() & 0xff]; // NOLINT + } + + // Returns the highest non 0 value used in distribution. + return -char_dist[0]; +} -- cgit v1.2.3