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diff --git a/third_party/aom/aom_dsp/noise_model.h b/third_party/aom/aom_dsp/noise_model.h
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+/*
+ * Copyright (c) 2017, 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.
+ */
+
+#ifndef AOM_AOM_DSP_NOISE_MODEL_H_
+#define AOM_AOM_DSP_NOISE_MODEL_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif  // __cplusplus
+
+#include <stdint.h>
+#include "aom_dsp/grain_synthesis.h"
+#include "aom_scale/yv12config.h"
+
+/*!\brief Wrapper of data required to represent linear system of eqns and soln.
+ */
+typedef struct {
+  double *A;
+  double *b;
+  double *x;
+  int n;
+} aom_equation_system_t;
+
+/*!\brief Representation of a piecewise linear curve
+ *
+ * Holds n points as (x, y) pairs, that store the curve.
+ */
+typedef struct {
+  double (*points)[2];
+  int num_points;
+} aom_noise_strength_lut_t;
+
+/*!\brief Init the noise strength lut with the given number of points*/
+int aom_noise_strength_lut_init(aom_noise_strength_lut_t *lut, int num_points);
+
+/*!\brief Frees the noise strength lut. */
+void aom_noise_strength_lut_free(aom_noise_strength_lut_t *lut);
+
+/*!\brief Evaluate the lut at the point x.
+ *
+ * \param[in] lut  The lut data.
+ * \param[in] x    The coordinate to evaluate the lut.
+ */
+double aom_noise_strength_lut_eval(const aom_noise_strength_lut_t *lut,
+                                   double x);
+
+/*!\brief Helper struct to model noise strength as a function of intensity.
+ *
+ * Internally, this structure holds a representation of a linear system
+ * of equations that models noise strength (standard deviation) as a
+ * function of intensity. The mapping is initially stored using a
+ * piecewise representation with evenly spaced bins that cover the entire
+ * domain from [min_intensity, max_intensity]. Each observation (x,y) gives a
+ * constraint of the form:
+ *   y_{i} (1 - a) + y_{i+1} a = y
+ * where y_{i} is the value of bin i and x_{i} <= x <= x_{i+1} and
+ * a = x/(x_{i+1} - x{i}). The equation system holds the corresponding
+ * normal equations.
+ *
+ * As there may be missing data, the solution is regularized to get a
+ * complete set of values for the bins. A reduced representation after
+ * solving can be obtained by getting the corresponding noise_strength_lut_t.
+ */
+typedef struct {
+  aom_equation_system_t eqns;
+  double min_intensity;
+  double max_intensity;
+  int num_bins;
+  int num_equations;
+  double total;
+} aom_noise_strength_solver_t;
+
+/*!\brief Initializes the noise solver with the given number of bins.
+ *
+ * Returns 0 if initialization fails.
+ *
+ * \param[in]  solver    The noise solver to be initialized.
+ * \param[in]  num_bins  Number of bins to use in the internal representation.
+ * \param[in]  bit_depth The bit depth used to derive {min,max}_intensity.
+ */
+int aom_noise_strength_solver_init(aom_noise_strength_solver_t *solver,
+                                   int num_bins, int bit_depth);
+void aom_noise_strength_solver_free(aom_noise_strength_solver_t *solver);
+
+/*!\brief Gets the x coordinate of bin i.
+ *
+ * \param[in]  i  The bin whose coordinate to query.
+ */
+double aom_noise_strength_solver_get_center(
+    const aom_noise_strength_solver_t *solver, int i);
+
+/*!\brief Add an observation of the block mean intensity to its noise strength.
+ *
+ * \param[in]  block_mean  The average block intensity,
+ * \param[in]  noise_std   The observed noise strength.
+ */
+void aom_noise_strength_solver_add_measurement(
+    aom_noise_strength_solver_t *solver, double block_mean, double noise_std);
+
+/*!\brief Solves the current set of equations for the noise strength. */
+int aom_noise_strength_solver_solve(aom_noise_strength_solver_t *solver);
+
+/*!\brief Fits a reduced piecewise linear lut to the internal solution
+ *
+ * \param[in] max_num_points  The maximum number of output points
+ * \param[out] lut  The output piecewise linear lut.
+ */
+int aom_noise_strength_solver_fit_piecewise(
+    const aom_noise_strength_solver_t *solver, int max_num_points,
+    aom_noise_strength_lut_t *lut);
+
+/*!\brief Helper for holding precomputed data for finding flat blocks.
+ *
+ * Internally a block is modeled with a low-order polynomial model. A
+ * planar model would be a bunch of equations like:
+ * <[y_i x_i 1], [a_1, a_2, a_3]>  = b_i
+ * for each point in the block. The system matrix A with row i as [y_i x_i 1]
+ * is maintained as is the inverse, inv(A'*A), so that the plane parameters
+ * can be fit for each block.
+ */
+typedef struct {
+  double *AtA_inv;
+  double *A;
+  int num_params;  // The number of parameters used for internal low-order model
+  int block_size;  // The block size the finder was initialized with
+  double normalization;  // Normalization factor (1 / (2^(bit_depth) - 1))
+  int use_highbd;        // Whether input data should be interpreted as uint16
+} aom_flat_block_finder_t;
+
+/*!\brief Init the block_finder with the given block size, bit_depth */
+int aom_flat_block_finder_init(aom_flat_block_finder_t *block_finder,
+                               int block_size, int bit_depth, int use_highbd);
+void aom_flat_block_finder_free(aom_flat_block_finder_t *block_finder);
+
+/*!\brief Helper to extract a block and low order "planar" model. */
+void aom_flat_block_finder_extract_block(
+    const aom_flat_block_finder_t *block_finder, const uint8_t *const data,
+    int w, int h, int stride, int offsx, int offsy, double *plane,
+    double *block);
+
+/*!\brief Runs the flat block finder on the input data.
+ *
+ * Find flat blocks in the input image data. Returns a map of
+ * flat_blocks, where the value of flat_blocks map will be non-zero
+ * when a block is determined to be flat. A higher value indicates a bigger
+ * confidence in the decision.
+ */
+int aom_flat_block_finder_run(const aom_flat_block_finder_t *block_finder,
+                              const uint8_t *const data, int w, int h,
+                              int stride, uint8_t *flat_blocks);
+
+// The noise shape indicates the allowed coefficients in the AR model.
+typedef enum {
+  AOM_NOISE_SHAPE_DIAMOND = 0,
+  AOM_NOISE_SHAPE_SQUARE = 1
+} aom_noise_shape;
+
+// The parameters of the noise model include the shape type, lag, the
+// bit depth of the input images provided, and whether the input images
+// will be using uint16 (or uint8) representation.
+typedef struct {
+  aom_noise_shape shape;
+  int lag;
+  int bit_depth;
+  int use_highbd;
+} aom_noise_model_params_t;
+
+/*!\brief State of a noise model estimate for a single channel.
+ *
+ * This contains a system of equations that can be used to solve
+ * for the auto-regressive coefficients as well as a noise strength
+ * solver that can be used to model noise strength as a function of
+ * intensity.
+ */
+typedef struct {
+  aom_equation_system_t eqns;
+  aom_noise_strength_solver_t strength_solver;
+  int num_observations;  // The number of observations in the eqn system
+  double ar_gain;        // The gain of the current AR filter
+} aom_noise_state_t;
+
+/*!\brief Complete model of noise for a planar video
+ *
+ * This includes a noise model for the latest frame and an aggregated
+ * estimate over all previous frames that had similar parameters.
+ */
+typedef struct {
+  aom_noise_model_params_t params;
+  aom_noise_state_t combined_state[3];  // Combined state per channel
+  aom_noise_state_t latest_state[3];    // Latest state per channel
+  int (*coords)[2];  // Offsets (x,y) of the coefficient samples
+  int n;             // Number of parameters (size of coords)
+  int bit_depth;
+} aom_noise_model_t;
+
+/*!\brief Result of a noise model update. */
+typedef enum {
+  AOM_NOISE_STATUS_OK = 0,
+  AOM_NOISE_STATUS_INVALID_ARGUMENT,
+  AOM_NOISE_STATUS_INSUFFICIENT_FLAT_BLOCKS,
+  AOM_NOISE_STATUS_DIFFERENT_NOISE_TYPE,
+  AOM_NOISE_STATUS_INTERNAL_ERROR,
+} aom_noise_status_t;
+
+/*!\brief Initializes a noise model with the given parameters.
+ *
+ * Returns 0 on failure.
+ */
+int aom_noise_model_init(aom_noise_model_t *model,
+                         const aom_noise_model_params_t params);
+void aom_noise_model_free(aom_noise_model_t *model);
+
+/*!\brief Updates the noise model with a new frame observation.
+ *
+ * Updates the noise model with measurements from the given input frame and a
+ * denoised variant of it. Noise is sampled from flat blocks using the flat
+ * block map.
+ *
+ * Returns a noise_status indicating if the update was successful. If the
+ * Update was successful, the combined_state is updated with measurements from
+ * the provided frame. If status is OK or DIFFERENT_NOISE_TYPE, the latest noise
+ * state will be updated with measurements from the provided frame.
+ *
+ * \param[in,out] noise_model     The noise model to be updated
+ * \param[in]     data            Raw frame data
+ * \param[in]     denoised        Denoised frame data.
+ * \param[in]     w               Frame width
+ * \param[in]     h               Frame height
+ * \param[in]     strides         Stride of the planes
+ * \param[in]     chroma_sub_log2 Chroma subsampling for planes != 0.
+ * \param[in]     flat_blocks     A map to blocks that have been determined flat
+ * \param[in]     block_size      The size of blocks.
+ */
+aom_noise_status_t aom_noise_model_update(
+    aom_noise_model_t *const noise_model, const uint8_t *const data[3],
+    const uint8_t *const denoised[3], int w, int h, int strides[3],
+    int chroma_sub_log2[2], const uint8_t *const flat_blocks, int block_size);
+
+/*\brief Save the "latest" estimate into the "combined" estimate.
+ *
+ * This is meant to be called when the noise modeling detected a change
+ * in parameters (or for example, if a user wanted to reset estimation at
+ * a shot boundary).
+ */
+void aom_noise_model_save_latest(aom_noise_model_t *noise_model);
+
+/*!\brief Converts the noise_model parameters to the corresponding
+ *    grain_parameters.
+ *
+ * The noise structs in this file are suitable for estimation (e.g., using
+ * floats), but the grain parameters in the bitstream are quantized. This
+ * function does the conversion by selecting the correct quantization levels.
+ */
+int aom_noise_model_get_grain_parameters(aom_noise_model_t *const noise_model,
+                                         aom_film_grain_t *film_grain);
+
+/*!\brief Perform a Wiener filter denoising in 2D using the provided noise psd.
+ *
+ * \param[in]     data            Raw frame data
+ * \param[out]    denoised        Denoised frame data
+ * \param[in]     w               Frame width
+ * \param[in]     h               Frame height
+ * \param[in]     stride          Stride of the planes
+ * \param[in]     chroma_sub_log2 Chroma subsampling for planes != 0.
+ * \param[in]     noise_psd       The power spectral density of the noise
+ * \param[in]     block_size      The size of blocks
+ * \param[in]     bit_depth       Bit depth of the image
+ * \param[in]     use_highbd      If true, uint8 pointers are interpreted as
+ *                                uint16 and stride is measured in uint16.
+ *                                This must be true when bit_depth >= 10.
+ */
+int aom_wiener_denoise_2d(const uint8_t *const data[3], uint8_t *denoised[3],
+                          int w, int h, int stride[3], int chroma_sub_log2[2],
+                          float *noise_psd[3], int block_size, int bit_depth,
+                          int use_highbd);
+
+struct aom_denoise_and_model_t;
+
+/*!\brief Denoise the buffer and model the residual noise.
+ *
+ * This is meant to be called sequentially on input frames. The input buffer
+ * is denoised and the residual noise is modelled. The current noise estimate
+ * is populated in film_grain. Returns true on success. The grain.apply_grain
+ * parameter will be true when the input buffer was successfully denoised and
+ * grain was modelled. Returns false on error.
+ *
+ * \param[in]      ctx   Struct allocated with aom_denoise_and_model_alloc
+ *                       that holds some buffers for denoising and the current
+ *                       noise estimate.
+ * \param[in/out]   buf  The raw input buffer to be denoised.
+ * \param[out]    grain  Output film grain parameters
+ */
+int aom_denoise_and_model_run(struct aom_denoise_and_model_t *ctx,
+                              YV12_BUFFER_CONFIG *buf, aom_film_grain_t *grain);
+
+/*!\brief Allocates a context that can be used for denoising and noise modeling.
+ *
+ * \param[in]  bit_depth   Bit depth of buffers this will be run on.
+ * \param[in]  block_size  Block size for noise modeling and flat block
+ *                         estimation
+ * \param[in]  noise_level The noise_level (2.5 for moderate noise, and 5 for
+ *                         higher levels of noise)
+ */
+struct aom_denoise_and_model_t *aom_denoise_and_model_alloc(int bit_depth,
+                                                            int block_size,
+                                                            float noise_level);
+
+/*!\brief Frees the denoise context allocated with aom_denoise_and_model_alloc
+ */
+void aom_denoise_and_model_free(struct aom_denoise_and_model_t *denoise_model);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif  // __cplusplus
+#endif  // AOM_AOM_DSP_NOISE_MODEL_H_