av1/encoder/global_motion.h

/*
 * 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.
 */

#ifndef AOM_AV1_ENCODER_GLOBAL_MOTION_H_
#define AOM_AV1_ENCODER_GLOBAL_MOTION_H_

#include "aom/aom_integer.h"
#include "aom_scale/yv12config.h"
#include "av1/common/mv.h"
#include "av1/common/warped_motion.h"

#ifdef __cplusplus
extern "C" {
#endif

#define MAX_CORNERS 4096
#define RANSAC_NUM_MOTIONS 1

typedef enum {
  GLOBAL_MOTION_FEATURE_BASED,
  GLOBAL_MOTION_DISFLOW_BASED,
} GlobalMotionEstimationType;

unsigned char *av1_downconvert_frame(YV12_BUFFER_CONFIG *frm, int bit_depth);

typedef struct {
  double params[MAX_PARAMDIM - 1];
  int *inliers;
  int num_inliers;
} MotionModel;

void av1_convert_model_to_params(const double *params,
                                 WarpedMotionParams *model);

int av1_is_enough_erroradvantage(double best_erroradvantage, int params_cost,
                                 int erroradv_type);

void av1_compute_feature_segmentation_map(uint8_t *segment_map, int width,
                                          int height, int *inliers,
                                          int num_inliers);

// Returns the av1_warp_error between "dst" and the result of applying the
// motion params that result from fine-tuning "wm" to "ref". Note that "wm" is
// modified in place.
int64_t av1_refine_integerized_param(
    WarpedMotionParams *wm, TransformationType wmtype, int use_hbd, int bd,
    uint8_t *ref, int r_width, int r_height, int r_stride, uint8_t *dst,
    int d_width, int d_height, int d_stride, int n_refinements,
    int64_t best_frame_error, uint8_t *segment_map, int segment_map_stride);

/*
  Computes "num_motions" candidate global motion parameters between two frames.
  The array "params_by_motion" should be length 8 * "num_motions". The ordering
  of each set of parameters is best described  by the homography:

        [x'     (m2 m3 m0   [x
    z .  y'  =   m4 m5 m1 *  y
         1]      m6 m7 1)    1]

  where m{i} represents the ith value in any given set of parameters.

  "num_inliers" should be length "num_motions", and will be populated with the
  number of inlier feature points for each motion. Params for which the
  num_inliers entry is 0 should be ignored by the caller.
*/
int av1_compute_global_motion(TransformationType type,
                              unsigned char *frm_buffer, int frm_width,
                              int frm_height, int frm_stride, int *frm_corners,
                              int num_frm_corners, YV12_BUFFER_CONFIG *ref,
                              int bit_depth,
                              GlobalMotionEstimationType gm_estimation_type,
                              int *num_inliers_by_motion,
                              MotionModel *params_by_motion, int num_motions);
#ifdef __cplusplus
}  // extern "C"
#endif
#endif  // AOM_AV1_ENCODER_GLOBAL_MOTION_H_