| /* |
| * Copyright (c) 2021, Alliance for Open Media. All rights reserved |
| * |
| * This source code is subject to the terms of the BSD 3-Clause Clear License |
| * and the Alliance for Open Media Patent License 1.0. If the BSD 3-Clause Clear |
| * License was not distributed with this source code in the LICENSE file, you |
| * can obtain it at aomedia.org/license/software-license/bsd-3-c-c/. 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 |
| * aomedia.org/license/patent-license/. |
| */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <memory.h> |
| #include <math.h> |
| #include <assert.h> |
| |
| #include "config/aom_dsp_rtcd.h" |
| |
| #include "av1/encoder/global_motion.h" |
| |
| #include "av1/common/convolve.h" |
| #include "av1/common/resize.h" |
| #include "av1/common/warped_motion.h" |
| |
| #include "av1/encoder/segmentation.h" |
| #include "av1/encoder/corner_detect.h" |
| #include "av1/encoder/corner_match.h" |
| #include "av1/encoder/ransac.h" |
| |
| #define MIN_INLIER_PROB 0.1 |
| |
| #define MIN_TRANS_THRESH (1 * GM_TRANS_DECODE_FACTOR) |
| |
| // Border over which to compute the global motion |
| #define ERRORADV_BORDER 0 |
| |
| // Number of pyramid levels in disflow computation |
| #define N_LEVELS 2 |
| // Size of square patches in the disflow dense grid |
| #define PATCH_SIZE 8 |
| // Center point of square patch |
| #define PATCH_CENTER ((PATCH_SIZE + 1) >> 1) |
| // Step size between patches, lower value means greater patch overlap |
| #define PATCH_STEP 1 |
| // Minimum size of border padding for disflow |
| #define MIN_PAD 7 |
| // Warp error convergence threshold for disflow |
| #define DISFLOW_ERROR_TR 0.01 |
| // Max number of iterations if warp convergence is not found |
| #define DISFLOW_MAX_ITR 10 |
| |
| // Struct for an image pyramid |
| typedef struct { |
| int n_levels; |
| int pad_size; |
| int has_gradient; |
| int widths[N_LEVELS]; |
| int heights[N_LEVELS]; |
| int strides[N_LEVELS]; |
| int level_loc[N_LEVELS]; |
| unsigned char *level_buffer; |
| double *level_dx_buffer; |
| double *level_dy_buffer; |
| } ImagePyramid; |
| |
| int av1_is_enough_erroradvantage(double best_erroradvantage, int params_cost) { |
| return best_erroradvantage < erroradv_tr && |
| best_erroradvantage * params_cost < erroradv_prod_tr; |
| } |
| |
| static void convert_to_params(const double *params, int32_t *model) { |
| int i; |
| #if !CONFIG_IMPROVED_GLOBAL_MOTION |
| int alpha_present = 0; |
| #endif // !CONFIG_IMPROVED_GLOBAL_MOTION |
| model[0] = (int32_t)floor(params[0] * (1 << GM_TRANS_PREC_BITS) + 0.5); |
| model[1] = (int32_t)floor(params[1] * (1 << GM_TRANS_PREC_BITS) + 0.5); |
| model[0] = (int32_t)clamp(model[0], GM_TRANS_MIN, GM_TRANS_MAX) * |
| GM_TRANS_DECODE_FACTOR; |
| model[1] = (int32_t)clamp(model[1], GM_TRANS_MIN, GM_TRANS_MAX) * |
| GM_TRANS_DECODE_FACTOR; |
| |
| for (i = 2; i < 6; ++i) { |
| const int diag_value = ((i == 2 || i == 5) ? (1 << GM_ALPHA_PREC_BITS) : 0); |
| model[i] = (int32_t)floor(params[i] * (1 << GM_ALPHA_PREC_BITS) + 0.5); |
| model[i] = |
| (int32_t)clamp(model[i] - diag_value, GM_ALPHA_MIN, GM_ALPHA_MAX); |
| #if !CONFIG_IMPROVED_GLOBAL_MOTION |
| alpha_present |= (model[i] != 0); |
| #endif // !CONFIG_IMPROVED_GLOBAL_MOTION |
| model[i] = (model[i] + diag_value) * GM_ALPHA_DECODE_FACTOR; |
| } |
| for (; i < 8; ++i) { |
| model[i] = (int32_t)floor(params[i] * (1 << GM_ROW3HOMO_PREC_BITS) + 0.5); |
| model[i] = (int32_t)clamp(model[i], GM_ROW3HOMO_MIN, GM_ROW3HOMO_MAX) * |
| GM_ROW3HOMO_DECODE_FACTOR; |
| #if !CONFIG_IMPROVED_GLOBAL_MOTION |
| alpha_present |= (model[i] != 0); |
| #endif // !CONFIG_IMPROVED_GLOBAL_MOTION |
| } |
| |
| #if !CONFIG_IMPROVED_GLOBAL_MOTION |
| if (!alpha_present) { |
| if (abs(model[0]) < MIN_TRANS_THRESH && abs(model[1]) < MIN_TRANS_THRESH) { |
| model[0] = 0; |
| model[1] = 0; |
| } |
| } |
| #endif // !CONFIG_IMPROVED_GLOBAL_MOTION |
| } |
| |
| void av1_convert_model_to_params(const double *params, |
| WarpedMotionParams *model) { |
| convert_to_params(params, model->wmmat); |
| model->wmtype = get_wmtype(model); |
| model->invalid = 0; |
| } |
| |
| // Adds some offset to a global motion parameter and handles |
| // all of the necessary precision shifts, clamping, and |
| // zero-centering. |
| static int32_t add_param_offset(int param_index, int32_t param_value, |
| int32_t offset) { |
| const int scale_vals[3] = { GM_TRANS_PREC_DIFF, GM_ALPHA_PREC_DIFF, |
| GM_ROW3HOMO_PREC_DIFF }; |
| const int clamp_vals[3] = { GM_TRANS_MAX, GM_ALPHA_MAX, GM_ROW3HOMO_MAX }; |
| // type of param: 0 - translation, 1 - affine, 2 - homography |
| const int param_type = (param_index < 2 ? 0 : (param_index < 6 ? 1 : 2)); |
| const int is_one_centered = (param_index == 2 || param_index == 5); |
| |
| // Make parameter zero-centered and offset the shift that was done to make |
| // it compatible with the warped model |
| param_value = (param_value - (is_one_centered << WARPEDMODEL_PREC_BITS)) >> |
| scale_vals[param_type]; |
| // Add desired offset to the rescaled/zero-centered parameter |
| param_value += offset; |
| // Clamp the parameter so it does not overflow the number of bits allotted |
| // to it in the bitstream |
| param_value = (int32_t)clamp(param_value, -clamp_vals[param_type], |
| clamp_vals[param_type]); |
| // Rescale the parameter to WARPEDMODEL_PRECISION_BITS so it is compatible |
| // with the warped motion library |
| param_value *= (1 << scale_vals[param_type]); |
| |
| // Undo the zero-centering step if necessary |
| return param_value + (is_one_centered << WARPEDMODEL_PREC_BITS); |
| } |
| |
| static void force_wmtype(WarpedMotionParams *wm, TransformationType wmtype) { |
| switch (wmtype) { |
| case IDENTITY: |
| wm->wmmat[0] = 0; |
| wm->wmmat[1] = 0; |
| AOM_FALLTHROUGH_INTENDED; |
| case TRANSLATION: |
| wm->wmmat[2] = 1 << WARPEDMODEL_PREC_BITS; |
| wm->wmmat[3] = 0; |
| AOM_FALLTHROUGH_INTENDED; |
| case ROTZOOM: |
| wm->wmmat[4] = -wm->wmmat[3]; |
| wm->wmmat[5] = wm->wmmat[2]; |
| AOM_FALLTHROUGH_INTENDED; |
| case AFFINE: wm->wmmat[6] = wm->wmmat[7] = 0; break; |
| default: assert(0); |
| } |
| wm->wmtype = wmtype; |
| } |
| |
| static int64_t highbd_warp_error( |
| WarpedMotionParams *wm, const uint16_t *const ref, int width, int height, |
| int stride, const uint16_t *const dst, int p_col, int p_row, int p_width, |
| int p_height, int p_stride, int subsampling_x, int subsampling_y, int bd, |
| int64_t best_error, uint8_t *segment_map, int segment_map_stride) { |
| int64_t gm_sumerr = 0; |
| const int error_bsize_w = AOMMIN(p_width, WARP_ERROR_BLOCK); |
| const int error_bsize_h = AOMMIN(p_height, WARP_ERROR_BLOCK); |
| uint16_t tmp[WARP_ERROR_BLOCK * WARP_ERROR_BLOCK]; |
| |
| ConvolveParams conv_params = get_conv_params(0, 0, bd); |
| for (int i = p_row; i < p_row + p_height; i += WARP_ERROR_BLOCK) { |
| for (int j = p_col; j < p_col + p_width; j += WARP_ERROR_BLOCK) { |
| int seg_x = j >> WARP_ERROR_BLOCK_LOG; |
| int seg_y = i >> WARP_ERROR_BLOCK_LOG; |
| // Only compute the error if this block contains inliers from the motion |
| // model |
| if (!segment_map[seg_y * segment_map_stride + seg_x]) continue; |
| // avoid warping extra 8x8 blocks in the padded region of the frame |
| // when p_width and p_height are not multiples of WARP_ERROR_BLOCK |
| const int warp_w = AOMMIN(error_bsize_w, p_col + p_width - j); |
| const int warp_h = AOMMIN(error_bsize_h, p_row + p_height - i); |
| highbd_warp_plane(wm, ref, width, height, stride, tmp, j, i, warp_w, |
| warp_h, WARP_ERROR_BLOCK, subsampling_x, subsampling_y, |
| bd, &conv_params); |
| gm_sumerr += av1_calc_highbd_frame_error(tmp, WARP_ERROR_BLOCK, |
| dst + j + i * p_stride, warp_w, |
| warp_h, p_stride, bd); |
| if (gm_sumerr > best_error) return INT64_MAX; |
| } |
| } |
| return gm_sumerr; |
| } |
| |
| int64_t av1_warp_error(WarpedMotionParams *wm, int bd, const uint16_t *ref, |
| int width, int height, int stride, uint16_t *dst, |
| int p_col, int p_row, int p_width, int p_height, |
| int p_stride, int subsampling_x, int subsampling_y, |
| int64_t best_error, uint8_t *segment_map, |
| int segment_map_stride) { |
| if (wm->wmtype <= AFFINE) { |
| #if CONFIG_EXTENDED_WARP_PREDICTION |
| av1_reduce_warp_model(wm); |
| #endif // CONFIG_EXTENDED_WARP_PREDICTION |
| if (!av1_get_shear_params(wm)) return INT64_MAX; |
| } |
| |
| return highbd_warp_error(wm, ref, width, height, stride, dst, p_col, p_row, |
| p_width, p_height, p_stride, subsampling_x, |
| subsampling_y, bd, best_error, segment_map, |
| segment_map_stride); |
| } |
| |
| // Factors used to calculate the thresholds for av1_warp_error |
| static double thresh_factors[GM_REFINEMENT_COUNT] = { 1.25, 1.20, 1.15, 1.10, |
| 1.05 }; |
| |
| static INLINE int64_t calc_approx_erroradv_threshold( |
| double scaling_factor, int64_t erroradv_threshold) { |
| return erroradv_threshold < |
| (int64_t)(((double)INT64_MAX / scaling_factor) + 0.5) |
| ? (int64_t)(scaling_factor * erroradv_threshold + 0.5) |
| : INT64_MAX; |
| } |
| |
| int64_t av1_refine_integerized_param( |
| WarpedMotionParams *wm, TransformationType wmtype, int bd, uint16_t *ref, |
| int r_width, int r_height, int r_stride, uint16_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, int64_t erroradv_threshold) { |
| static const int max_trans_model_params[TRANS_TYPES] = { 0, 2, 4, 6 }; |
| const int border = ERRORADV_BORDER; |
| int i = 0, p; |
| int n_params = max_trans_model_params[wmtype]; |
| int32_t *param_mat = wm->wmmat; |
| int64_t step_error, best_error; |
| int32_t step; |
| int32_t *param; |
| int32_t curr_param; |
| int32_t best_param; |
| |
| force_wmtype(wm, wmtype); |
| best_error = |
| av1_warp_error(wm, bd, ref, r_width, r_height, r_stride, |
| dst + border * d_stride + border, border, border, |
| d_width - 2 * border, d_height - 2 * border, d_stride, 0, |
| 0, best_frame_error, segment_map, segment_map_stride); |
| best_error = AOMMIN(best_error, best_frame_error); |
| step = 1 << (n_refinements - 1); |
| for (i = 0; i < n_refinements; i++, step >>= 1) { |
| int64_t error_adv_thresh = |
| calc_approx_erroradv_threshold(thresh_factors[i], erroradv_threshold); |
| for (p = 0; p < n_params; ++p) { |
| int step_dir = 0; |
| // Skip searches for parameters that are forced to be 0 |
| param = param_mat + p; |
| curr_param = *param; |
| best_param = curr_param; |
| // look to the left |
| *param = add_param_offset(p, curr_param, -step); |
| step_error = |
| av1_warp_error(wm, bd, ref, r_width, r_height, r_stride, |
| dst + border * d_stride + border, border, border, |
| d_width - 2 * border, d_height - 2 * border, d_stride, |
| 0, 0, AOMMIN(best_error, error_adv_thresh), |
| segment_map, segment_map_stride); |
| if (step_error < best_error) { |
| best_error = step_error; |
| best_param = *param; |
| step_dir = -1; |
| } |
| |
| // look to the right |
| *param = add_param_offset(p, curr_param, step); |
| step_error = |
| av1_warp_error(wm, bd, ref, r_width, r_height, r_stride, |
| dst + border * d_stride + border, border, border, |
| d_width - 2 * border, d_height - 2 * border, d_stride, |
| 0, 0, AOMMIN(best_error, error_adv_thresh), |
| segment_map, segment_map_stride); |
| if (step_error < best_error) { |
| best_error = step_error; |
| best_param = *param; |
| step_dir = 1; |
| } |
| *param = best_param; |
| |
| // look to the direction chosen above repeatedly until error increases |
| // for the biggest step size |
| while (step_dir) { |
| *param = add_param_offset(p, best_param, step * step_dir); |
| step_error = |
| av1_warp_error(wm, bd, ref, r_width, r_height, r_stride, |
| dst + border * d_stride + border, border, border, |
| d_width - 2 * border, d_height - 2 * border, |
| d_stride, 0, 0, AOMMIN(best_error, error_adv_thresh), |
| segment_map, segment_map_stride); |
| if (step_error < best_error) { |
| best_error = step_error; |
| best_param = *param; |
| } else { |
| *param = best_param; |
| step_dir = 0; |
| } |
| } |
| } |
| } |
| force_wmtype(wm, wmtype); |
| wm->wmtype = get_wmtype(wm); |
| return best_error; |
| } |
| |
| unsigned char *av1_downconvert_frame(YV12_BUFFER_CONFIG *frm, int bit_depth) { |
| int i, j; |
| uint16_t *orig_buf = frm->y_buffer; |
| uint8_t *buf_8bit = frm->y_buffer_8bit; |
| assert(buf_8bit); |
| if (!frm->buf_8bit_valid) { |
| for (i = 0; i < frm->y_height; ++i) { |
| for (j = 0; j < frm->y_width; ++j) { |
| buf_8bit[i * frm->y_stride + j] = |
| orig_buf[i * frm->y_stride + j] >> (bit_depth - 8); |
| } |
| } |
| frm->buf_8bit_valid = 1; |
| } |
| #if CONFIG_DEBUG |
| else { |
| // frm->buf_8bit_valid == 1. So, double check that 'buf_8bit' is correct. |
| for (i = 0; i < frm->y_height; ++i) { |
| for (j = 0; j < frm->y_width; ++j) { |
| assert(buf_8bit[i * frm->y_stride + j] == |
| (orig_buf[i * frm->y_stride + j] >> (bit_depth - 8))); |
| } |
| } |
| } |
| #endif // CONFIG_DEBUG |
| return buf_8bit; |
| } |
| |
| static void get_inliers_from_indices(MotionModel *params, |
| int *correspondences) { |
| int *inliers_tmp = (int *)aom_malloc(2 * MAX_CORNERS * sizeof(*inliers_tmp)); |
| memset(inliers_tmp, 0, 2 * MAX_CORNERS * sizeof(*inliers_tmp)); |
| |
| for (int i = 0; i < params->num_inliers; i++) { |
| int index = params->inliers[i]; |
| inliers_tmp[2 * i] = correspondences[4 * index]; |
| inliers_tmp[2 * i + 1] = correspondences[4 * index + 1]; |
| } |
| memcpy(params->inliers, inliers_tmp, sizeof(*inliers_tmp) * 2 * MAX_CORNERS); |
| aom_free(inliers_tmp); |
| } |
| |
| #define FEAT_COUNT_TR 3 |
| #define SEG_COUNT_TR 0.40 |
| void av1_compute_feature_segmentation_map(uint8_t *segment_map, int width, |
| int height, int *inliers, |
| int num_inliers) { |
| int seg_count = 0; |
| memset(segment_map, 0, sizeof(*segment_map) * width * height); |
| |
| for (int i = 0; i < num_inliers; i++) { |
| int x = inliers[i * 2]; |
| int y = inliers[i * 2 + 1]; |
| int seg_x = x >> WARP_ERROR_BLOCK_LOG; |
| int seg_y = y >> WARP_ERROR_BLOCK_LOG; |
| segment_map[seg_y * width + seg_x] += 1; |
| } |
| |
| for (int i = 0; i < height; i++) { |
| for (int j = 0; j < width; j++) { |
| uint8_t feat_count = segment_map[i * width + j]; |
| segment_map[i * width + j] = (feat_count >= FEAT_COUNT_TR); |
| seg_count += (segment_map[i * width + j]); |
| } |
| } |
| |
| // If this motion does not make up a large enough portion of the frame, |
| // use the unsegmented version of the error metric |
| if (seg_count < (width * height * SEG_COUNT_TR)) |
| memset(segment_map, 1, width * height * sizeof(*segment_map)); |
| } |
| |
| static int compute_global_motion_feature_based( |
| TransformationType type, unsigned char *src_buffer, int src_width, |
| int src_height, int src_stride, int *src_corners, int num_src_corners, |
| YV12_BUFFER_CONFIG *ref, int bit_depth, int *num_inliers_by_motion, |
| MotionModel *params_by_motion, int num_motions) { |
| int i; |
| int num_ref_corners; |
| int num_correspondences; |
| int *correspondences; |
| int ref_corners[2 * MAX_CORNERS]; |
| unsigned char *ref_buffer; |
| RansacFunc ransac = av1_get_ransac_type(type); |
| |
| ref_buffer = av1_downconvert_frame(ref, bit_depth); |
| |
| num_ref_corners = |
| av1_fast_corner_detect(ref_buffer, ref->y_width, ref->y_height, |
| ref->y_stride, ref_corners, MAX_CORNERS); |
| |
| // find correspondences between the two images |
| correspondences = |
| (int *)malloc(num_src_corners * 4 * sizeof(*correspondences)); |
| num_correspondences = av1_determine_correspondence( |
| src_buffer, (int *)src_corners, num_src_corners, ref_buffer, |
| (int *)ref_corners, num_ref_corners, src_width, src_height, src_stride, |
| ref->y_stride, correspondences); |
| |
| ransac(correspondences, num_correspondences, num_inliers_by_motion, |
| params_by_motion, num_motions); |
| |
| // Set num_inliers = 0 for motions with too few inliers so they are ignored. |
| for (i = 0; i < num_motions; ++i) { |
| if (num_inliers_by_motion[i] < MIN_INLIER_PROB * num_correspondences || |
| num_correspondences == 0) { |
| num_inliers_by_motion[i] = 0; |
| } else { |
| get_inliers_from_indices(¶ms_by_motion[i], correspondences); |
| } |
| } |
| |
| free(correspondences); |
| |
| // Return true if any one of the motions has inliers. |
| for (i = 0; i < num_motions; ++i) { |
| if (num_inliers_by_motion[i] > 0) return 1; |
| } |
| return 0; |
| } |
| |
| // Don't use points around the frame border since they are less reliable |
| static INLINE int valid_point(int x, int y, int width, int height) { |
| return (x > (PATCH_SIZE + PATCH_CENTER)) && |
| (x < (width - PATCH_SIZE - PATCH_CENTER)) && |
| (y > (PATCH_SIZE + PATCH_CENTER)) && |
| (y < (height - PATCH_SIZE - PATCH_CENTER)); |
| } |
| |
| static int determine_disflow_correspondence(int *frm_corners, |
| int num_frm_corners, double *flow_u, |
| double *flow_v, int width, |
| int height, int stride, |
| double *correspondences) { |
| int num_correspondences = 0; |
| int x, y; |
| for (int i = 0; i < num_frm_corners; ++i) { |
| x = frm_corners[2 * i]; |
| y = frm_corners[2 * i + 1]; |
| if (valid_point(x, y, width, height)) { |
| correspondences[4 * num_correspondences] = x; |
| correspondences[4 * num_correspondences + 1] = y; |
| correspondences[4 * num_correspondences + 2] = x + flow_u[y * stride + x]; |
| correspondences[4 * num_correspondences + 3] = y + flow_v[y * stride + x]; |
| num_correspondences++; |
| } |
| } |
| return num_correspondences; |
| } |
| |
| static double getCubicValue(double p[4], double x) { |
| return p[1] + 0.5 * x * |
| (p[2] - p[0] + |
| x * (2.0 * p[0] - 5.0 * p[1] + 4.0 * p[2] - p[3] + |
| x * (3.0 * (p[1] - p[2]) + p[3] - p[0]))); |
| } |
| |
| static void get_subcolumn(unsigned char *ref, double col[4], int stride, int x, |
| int y_start) { |
| int i; |
| for (i = 0; i < 4; ++i) { |
| col[i] = ref[(i + y_start) * stride + x]; |
| } |
| } |
| |
| static double bicubic(unsigned char *ref, double x, double y, int stride) { |
| double arr[4]; |
| int k; |
| int i = (int)x; |
| int j = (int)y; |
| for (k = 0; k < 4; ++k) { |
| double arr_temp[4]; |
| get_subcolumn(ref, arr_temp, stride, i + k - 1, j - 1); |
| arr[k] = getCubicValue(arr_temp, y - j); |
| } |
| return getCubicValue(arr, x - i); |
| } |
| |
| // Interpolate a warped block using bicubic interpolation when possible |
| static unsigned char interpolate(unsigned char *ref, double x, double y, |
| int width, int height, int stride) { |
| if (x < 0 && y < 0) |
| return ref[0]; |
| else if (x < 0 && y > height - 1) |
| return ref[(height - 1) * stride]; |
| else if (x > width - 1 && y < 0) |
| return ref[width - 1]; |
| else if (x > width - 1 && y > height - 1) |
| return ref[(height - 1) * stride + (width - 1)]; |
| else if (x < 0) { |
| int v; |
| int i = (int)y; |
| double a = y - i; |
| if (y > 1 && y < height - 2) { |
| double arr[4]; |
| get_subcolumn(ref, arr, stride, 0, i - 1); |
| return clamp((int)(getCubicValue(arr, a) + 0.5), 0, 255); |
| } |
| v = (int)(ref[i * stride] * (1 - a) + ref[(i + 1) * stride] * a + 0.5); |
| return clamp(v, 0, 255); |
| } else if (y < 0) { |
| int v; |
| int j = (int)x; |
| double b = x - j; |
| if (x > 1 && x < width - 2) { |
| double arr[4] = { ref[j - 1], ref[j], ref[j + 1], ref[j + 2] }; |
| return clamp((int)(getCubicValue(arr, b) + 0.5), 0, 255); |
| } |
| v = (int)(ref[j] * (1 - b) + ref[j + 1] * b + 0.5); |
| return clamp(v, 0, 255); |
| } else if (x > width - 1) { |
| int v; |
| int i = (int)y; |
| double a = y - i; |
| if (y > 1 && y < height - 2) { |
| double arr[4]; |
| get_subcolumn(ref, arr, stride, width - 1, i - 1); |
| return clamp((int)(getCubicValue(arr, a) + 0.5), 0, 255); |
| } |
| v = (int)(ref[i * stride + width - 1] * (1 - a) + |
| ref[(i + 1) * stride + width - 1] * a + 0.5); |
| return clamp(v, 0, 255); |
| } else if (y > height - 1) { |
| int v; |
| int j = (int)x; |
| double b = x - j; |
| if (x > 1 && x < width - 2) { |
| int row = (height - 1) * stride; |
| double arr[4] = { ref[row + j - 1], ref[row + j], ref[row + j + 1], |
| ref[row + j + 2] }; |
| return clamp((int)(getCubicValue(arr, b) + 0.5), 0, 255); |
| } |
| v = (int)(ref[(height - 1) * stride + j] * (1 - b) + |
| ref[(height - 1) * stride + j + 1] * b + 0.5); |
| return clamp(v, 0, 255); |
| } else if (x > 1 && y > 1 && x < width - 2 && y < height - 2) { |
| return clamp((int)(bicubic(ref, x, y, stride) + 0.5), 0, 255); |
| } else { |
| int i = (int)y; |
| int j = (int)x; |
| double a = y - i; |
| double b = x - j; |
| int v = (int)(ref[i * stride + j] * (1 - a) * (1 - b) + |
| ref[i * stride + j + 1] * (1 - a) * b + |
| ref[(i + 1) * stride + j] * a * (1 - b) + |
| ref[(i + 1) * stride + j + 1] * a * b); |
| return clamp(v, 0, 255); |
| } |
| } |
| |
| // Warps a block using flow vector [u, v] and computes the mse |
| static double compute_warp_and_error(unsigned char *ref, unsigned char *frm, |
| int width, int height, int stride, int x, |
| int y, double u, double v, int16_t *dt) { |
| int i, j; |
| unsigned char warped; |
| double x_w, y_w; |
| double mse = 0; |
| int16_t err = 0; |
| for (i = y; i < y + PATCH_SIZE; ++i) |
| for (j = x; j < x + PATCH_SIZE; ++j) { |
| x_w = (double)j + u; |
| y_w = (double)i + v; |
| warped = interpolate(ref, x_w, y_w, width, height, stride); |
| err = warped - frm[j + i * stride]; |
| mse += err * err; |
| dt[(i - y) * PATCH_SIZE + (j - x)] = err; |
| } |
| |
| mse /= (PATCH_SIZE * PATCH_SIZE); |
| return mse; |
| } |
| |
| // Computes the components of the system of equations used to solve for |
| // a flow vector. This includes: |
| // 1.) The hessian matrix for optical flow. This matrix is in the |
| // form of: |
| // |
| // M = |sum(dx * dx) sum(dx * dy)| |
| // |sum(dx * dy) sum(dy * dy)| |
| // |
| // 2.) b = |sum(dx * dt)| |
| // |sum(dy * dt)| |
| // Where the sums are computed over a square window of PATCH_SIZE. |
| static INLINE void compute_flow_system(const double *dx, int dx_stride, |
| const double *dy, int dy_stride, |
| const int16_t *dt, int dt_stride, |
| double *M, double *b) { |
| for (int i = 0; i < PATCH_SIZE; i++) { |
| for (int j = 0; j < PATCH_SIZE; j++) { |
| M[0] += dx[i * dx_stride + j] * dx[i * dx_stride + j]; |
| M[1] += dx[i * dx_stride + j] * dy[i * dy_stride + j]; |
| M[3] += dy[i * dy_stride + j] * dy[i * dy_stride + j]; |
| |
| b[0] += dx[i * dx_stride + j] * dt[i * dt_stride + j]; |
| b[1] += dy[i * dy_stride + j] * dt[i * dt_stride + j]; |
| } |
| } |
| |
| M[2] = M[1]; |
| } |
| |
| // Solves a general Mx = b where M is a 2x2 matrix and b is a 2x1 matrix |
| static INLINE void solve_2x2_system(const double *M, const double *b, |
| double *output_vec) { |
| double M_0 = M[0]; |
| double M_3 = M[3]; |
| double det = (M_0 * M_3) - (M[1] * M[2]); |
| if (det < 1e-5) { |
| // Handle singular matrix |
| // TODO(sarahparker) compare results using pseudo inverse instead |
| M_0 += 1e-10; |
| M_3 += 1e-10; |
| det = (M_0 * M_3) - (M[1] * M[2]); |
| } |
| const double det_inv = 1 / det; |
| const double mult_b0 = det_inv * b[0]; |
| const double mult_b1 = det_inv * b[1]; |
| output_vec[0] = M_3 * mult_b0 - M[1] * mult_b1; |
| output_vec[1] = -M[2] * mult_b0 + M_0 * mult_b1; |
| } |
| |
| /* |
| static INLINE void image_difference(const uint8_t *src, int src_stride, |
| const uint8_t *ref, int ref_stride, |
| int16_t *dst, int dst_stride, int height, |
| int width) { |
| const int block_unit = 8; |
| // Take difference in 8x8 blocks to make use of optimized diff function |
| for (int i = 0; i < height; i += block_unit) { |
| for (int j = 0; j < width; j += block_unit) { |
| aom_subtract_block(block_unit, block_unit, dst + i * dst_stride + j, |
| dst_stride, src + i * src_stride + j, src_stride, |
| ref + i * ref_stride + j, ref_stride); |
| } |
| } |
| } |
| */ |
| |
| // Compute an image gradient using a sobel filter. |
| // If dir == 1, compute the x gradient. If dir == 0, compute y. This function |
| // assumes the images have been padded so that they can be processed in units |
| // of 8. |
| static INLINE void sobel_xy_image_gradient(const uint8_t *src, int src_stride, |
| double *dst, int dst_stride, |
| int height, int width, int dir) { |
| double norm = 1.0; |
| // TODO(sarahparker) experiment with doing this over larger block sizes |
| const int block_unit = 8; |
| // Filter in 8x8 blocks to eventually make use of optimized convolve function |
| for (int i = 0; i < height; i += block_unit) { |
| for (int j = 0; j < width; j += block_unit) { |
| av1_convolve_2d_sobel_y_c(src + i * src_stride + j, src_stride, |
| dst + i * dst_stride + j, dst_stride, |
| block_unit, block_unit, dir, norm); |
| } |
| } |
| } |
| |
| static ImagePyramid *alloc_pyramid(int width, int height, int pad_size, |
| int compute_gradient) { |
| ImagePyramid *pyr = aom_malloc(sizeof(*pyr)); |
| pyr->has_gradient = compute_gradient; |
| // 2 * width * height is the upper bound for a buffer that fits |
| // all pyramid levels + padding for each level |
| const int buffer_size = sizeof(*pyr->level_buffer) * 2 * width * height + |
| (width + 2 * pad_size) * 2 * pad_size * N_LEVELS; |
| pyr->level_buffer = aom_malloc(buffer_size); |
| memset(pyr->level_buffer, 0, buffer_size); |
| |
| if (compute_gradient) { |
| const int gradient_size = |
| sizeof(*pyr->level_dx_buffer) * 2 * width * height + |
| (width + 2 * pad_size) * 2 * pad_size * N_LEVELS; |
| pyr->level_dx_buffer = aom_malloc(gradient_size); |
| pyr->level_dy_buffer = aom_malloc(gradient_size); |
| memset(pyr->level_dx_buffer, 0, gradient_size); |
| memset(pyr->level_dy_buffer, 0, gradient_size); |
| } |
| return pyr; |
| } |
| |
| static void free_pyramid(ImagePyramid *pyr) { |
| aom_free(pyr->level_buffer); |
| if (pyr->has_gradient) { |
| aom_free(pyr->level_dx_buffer); |
| aom_free(pyr->level_dy_buffer); |
| } |
| aom_free(pyr); |
| } |
| |
| static INLINE void update_level_dims(ImagePyramid *frm_pyr, int level) { |
| frm_pyr->widths[level] = frm_pyr->widths[level - 1] >> 1; |
| frm_pyr->heights[level] = frm_pyr->heights[level - 1] >> 1; |
| frm_pyr->strides[level] = frm_pyr->widths[level] + 2 * frm_pyr->pad_size; |
| // Point the beginning of the next level buffer to the correct location inside |
| // the padded border |
| frm_pyr->level_loc[level] = |
| frm_pyr->level_loc[level - 1] + |
| frm_pyr->strides[level - 1] * |
| (2 * frm_pyr->pad_size + frm_pyr->heights[level - 1]); |
| } |
| |
| // Compute coarse to fine pyramids for a frame |
| static void compute_flow_pyramids(unsigned char *frm, const int frm_width, |
| const int frm_height, const int frm_stride, |
| int n_levels, int pad_size, int compute_grad, |
| ImagePyramid *frm_pyr) { |
| int cur_width, cur_height, cur_stride, cur_loc; |
| assert((frm_width >> n_levels) > 0); |
| assert((frm_height >> n_levels) > 0); |
| |
| // Initialize first level |
| frm_pyr->n_levels = n_levels; |
| frm_pyr->pad_size = pad_size; |
| frm_pyr->widths[0] = frm_width; |
| frm_pyr->heights[0] = frm_height; |
| frm_pyr->strides[0] = frm_width + 2 * frm_pyr->pad_size; |
| // Point the beginning of the level buffer to the location inside |
| // the padded border |
| frm_pyr->level_loc[0] = |
| frm_pyr->strides[0] * frm_pyr->pad_size + frm_pyr->pad_size; |
| // This essentially copies the original buffer into the pyramid buffer |
| // without the original padding |
| av1_resize_plane(frm, frm_height, frm_width, frm_stride, |
| frm_pyr->level_buffer + frm_pyr->level_loc[0], |
| frm_pyr->heights[0], frm_pyr->widths[0], |
| frm_pyr->strides[0]); |
| |
| if (compute_grad) { |
| cur_width = frm_pyr->widths[0]; |
| cur_height = frm_pyr->heights[0]; |
| cur_stride = frm_pyr->strides[0]; |
| cur_loc = frm_pyr->level_loc[0]; |
| assert(frm_pyr->has_gradient && frm_pyr->level_dx_buffer != NULL && |
| frm_pyr->level_dy_buffer != NULL); |
| // Computation x gradient |
| sobel_xy_image_gradient(frm_pyr->level_buffer + cur_loc, cur_stride, |
| frm_pyr->level_dx_buffer + cur_loc, cur_stride, |
| cur_height, cur_width, 1); |
| |
| // Computation y gradient |
| sobel_xy_image_gradient(frm_pyr->level_buffer + cur_loc, cur_stride, |
| frm_pyr->level_dy_buffer + cur_loc, cur_stride, |
| cur_height, cur_width, 0); |
| } |
| |
| // Start at the finest level and resize down to the coarsest level |
| for (int level = 1; level < n_levels; ++level) { |
| update_level_dims(frm_pyr, level); |
| cur_width = frm_pyr->widths[level]; |
| cur_height = frm_pyr->heights[level]; |
| cur_stride = frm_pyr->strides[level]; |
| cur_loc = frm_pyr->level_loc[level]; |
| |
| av1_resize_plane(frm_pyr->level_buffer + frm_pyr->level_loc[level - 1], |
| frm_pyr->heights[level - 1], frm_pyr->widths[level - 1], |
| frm_pyr->strides[level - 1], |
| frm_pyr->level_buffer + cur_loc, cur_height, cur_width, |
| cur_stride); |
| |
| if (compute_grad) { |
| assert(frm_pyr->has_gradient && frm_pyr->level_dx_buffer != NULL && |
| frm_pyr->level_dy_buffer != NULL); |
| // Computation x gradient |
| sobel_xy_image_gradient(frm_pyr->level_buffer + cur_loc, cur_stride, |
| frm_pyr->level_dx_buffer + cur_loc, cur_stride, |
| cur_height, cur_width, 1); |
| |
| // Computation y gradient |
| sobel_xy_image_gradient(frm_pyr->level_buffer + cur_loc, cur_stride, |
| frm_pyr->level_dy_buffer + cur_loc, cur_stride, |
| cur_height, cur_width, 0); |
| } |
| } |
| } |
| |
| static INLINE void compute_flow_at_point(unsigned char *frm, unsigned char *ref, |
| double *dx, double *dy, int x, int y, |
| int width, int height, int stride, |
| double *u, double *v) { |
| double M[4] = { 0 }; |
| double b[2] = { 0 }; |
| double tmp_output_vec[2] = { 0 }; |
| double error = 0; |
| int16_t dt[PATCH_SIZE * PATCH_SIZE]; |
| double o_u = *u; |
| double o_v = *v; |
| |
| for (int itr = 0; itr < DISFLOW_MAX_ITR; itr++) { |
| error = compute_warp_and_error(ref, frm, width, height, stride, x, y, *u, |
| *v, dt); |
| if (error <= DISFLOW_ERROR_TR) break; |
| compute_flow_system(dx, stride, dy, stride, dt, PATCH_SIZE, M, b); |
| solve_2x2_system(M, b, tmp_output_vec); |
| *u += tmp_output_vec[0]; |
| *v += tmp_output_vec[1]; |
| } |
| if (fabs(*u - o_u) > PATCH_SIZE || fabs(*v - o_u) > PATCH_SIZE) { |
| *u = o_u; |
| *v = o_v; |
| } |
| } |
| |
| // make sure flow_u and flow_v start at 0 |
| static void compute_flow_field(ImagePyramid *frm_pyr, ImagePyramid *ref_pyr, |
| double *flow_u, double *flow_v) { |
| int cur_width, cur_height, cur_stride, cur_loc, patch_loc, patch_center; |
| double *u_upscale = |
| aom_malloc(frm_pyr->strides[0] * frm_pyr->heights[0] * sizeof(*flow_u)); |
| double *v_upscale = |
| aom_malloc(frm_pyr->strides[0] * frm_pyr->heights[0] * sizeof(*flow_v)); |
| |
| assert(frm_pyr->n_levels == ref_pyr->n_levels); |
| |
| // Compute flow field from coarsest to finest level of the pyramid |
| for (int level = frm_pyr->n_levels - 1; level >= 0; --level) { |
| cur_width = frm_pyr->widths[level]; |
| cur_height = frm_pyr->heights[level]; |
| cur_stride = frm_pyr->strides[level]; |
| cur_loc = frm_pyr->level_loc[level]; |
| |
| for (int i = PATCH_SIZE; i < cur_height - PATCH_SIZE; i += PATCH_STEP) { |
| for (int j = PATCH_SIZE; j < cur_width - PATCH_SIZE; j += PATCH_STEP) { |
| patch_loc = i * cur_stride + j; |
| patch_center = patch_loc + PATCH_CENTER * cur_stride + PATCH_CENTER; |
| compute_flow_at_point(frm_pyr->level_buffer + cur_loc, |
| ref_pyr->level_buffer + cur_loc, |
| frm_pyr->level_dx_buffer + cur_loc + patch_loc, |
| frm_pyr->level_dy_buffer + cur_loc + patch_loc, j, |
| i, cur_width, cur_height, cur_stride, |
| flow_u + patch_center, flow_v + patch_center); |
| } |
| } |
| // TODO(sarahparker) Replace this with upscale function in resize.c |
| if (level > 0) { |
| int h_upscale = frm_pyr->heights[level - 1]; |
| int w_upscale = frm_pyr->widths[level - 1]; |
| int s_upscale = frm_pyr->strides[level - 1]; |
| for (int i = 0; i < h_upscale; ++i) { |
| for (int j = 0; j < w_upscale; ++j) { |
| u_upscale[j + i * s_upscale] = |
| flow_u[(int)(j >> 1) + (int)(i >> 1) * cur_stride]; |
| v_upscale[j + i * s_upscale] = |
| flow_v[(int)(j >> 1) + (int)(i >> 1) * cur_stride]; |
| } |
| } |
| memcpy(flow_u, u_upscale, |
| frm_pyr->strides[0] * frm_pyr->heights[0] * sizeof(*flow_u)); |
| memcpy(flow_v, v_upscale, |
| frm_pyr->strides[0] * frm_pyr->heights[0] * sizeof(*flow_v)); |
| } |
| } |
| aom_free(u_upscale); |
| aom_free(v_upscale); |
| } |
| |
| static int compute_global_motion_disflow_based( |
| 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, int *num_inliers_by_motion, |
| MotionModel *params_by_motion, int num_motions) { |
| unsigned char *ref_buffer; |
| const int ref_width = ref->y_width; |
| const int ref_height = ref->y_height; |
| const int pad_size = AOMMAX(PATCH_SIZE, MIN_PAD); |
| int num_correspondences; |
| double *correspondences; |
| RansacFuncDouble ransac = av1_get_ransac_double_prec_type(type); |
| assert(frm_width == ref_width); |
| assert(frm_height == ref_height); |
| |
| // Ensure the number of pyramid levels will work with the frame resolution |
| const int msb = |
| frm_width < frm_height ? get_msb(frm_width) : get_msb(frm_height); |
| const int n_levels = AOMMIN(msb, N_LEVELS); |
| |
| ref_buffer = av1_downconvert_frame(ref, bit_depth); |
| |
| // TODO(sarahparker) We will want to do the source pyramid computation |
| // outside of this function so it doesn't get recomputed for every |
| // reference. We also don't need to compute every pyramid level for the |
| // reference in advance, since lower levels can be overwritten once their |
| // flow field is computed and upscaled. I'll add these optimizations |
| // once the full implementation is working. |
| // Allocate frm image pyramids |
| int compute_gradient = 1; |
| ImagePyramid *frm_pyr = |
| alloc_pyramid(frm_width, frm_height, pad_size, compute_gradient); |
| compute_flow_pyramids(frm_buffer, frm_width, frm_height, frm_stride, n_levels, |
| pad_size, compute_gradient, frm_pyr); |
| // Allocate ref image pyramids |
| compute_gradient = 0; |
| ImagePyramid *ref_pyr = |
| alloc_pyramid(ref_width, ref_height, pad_size, compute_gradient); |
| compute_flow_pyramids(ref_buffer, ref_width, ref_height, ref->y_stride, |
| n_levels, pad_size, compute_gradient, ref_pyr); |
| |
| double *flow_u = |
| aom_malloc(frm_pyr->strides[0] * frm_pyr->heights[0] * sizeof(*flow_u)); |
| double *flow_v = |
| aom_malloc(frm_pyr->strides[0] * frm_pyr->heights[0] * sizeof(*flow_v)); |
| |
| memset(flow_u, 0, |
| frm_pyr->strides[0] * frm_pyr->heights[0] * sizeof(*flow_u)); |
| memset(flow_v, 0, |
| frm_pyr->strides[0] * frm_pyr->heights[0] * sizeof(*flow_v)); |
| |
| compute_flow_field(frm_pyr, ref_pyr, flow_u, flow_v); |
| |
| // find correspondences between the two images using the flow field |
| correspondences = aom_malloc(num_frm_corners * 4 * sizeof(*correspondences)); |
| num_correspondences = determine_disflow_correspondence( |
| frm_corners, num_frm_corners, flow_u, flow_v, frm_width, frm_height, |
| frm_pyr->strides[0], correspondences); |
| ransac(correspondences, num_correspondences, num_inliers_by_motion, |
| params_by_motion, num_motions); |
| |
| free_pyramid(frm_pyr); |
| free_pyramid(ref_pyr); |
| aom_free(correspondences); |
| aom_free(flow_u); |
| aom_free(flow_v); |
| // Set num_inliers = 0 for motions with too few inliers so they are ignored. |
| for (int i = 0; i < num_motions; ++i) { |
| if (num_inliers_by_motion[i] < MIN_INLIER_PROB * num_correspondences) { |
| num_inliers_by_motion[i] = 0; |
| } |
| } |
| |
| // Return true if any one of the motions has inliers. |
| for (int i = 0; i < num_motions; ++i) { |
| if (num_inliers_by_motion[i] > 0) return 1; |
| } |
| return 0; |
| } |
| |
| int av1_compute_global_motion(TransformationType type, |
| unsigned char *src_buffer, int src_width, |
| int src_height, int src_stride, int *src_corners, |
| int num_src_corners, YV12_BUFFER_CONFIG *ref, |
| int bit_depth, |
| GlobalMotionEstimationType gm_estimation_type, |
| int *num_inliers_by_motion, |
| MotionModel *params_by_motion, int num_motions) { |
| switch (gm_estimation_type) { |
| case GLOBAL_MOTION_FEATURE_BASED: |
| return compute_global_motion_feature_based( |
| type, src_buffer, src_width, src_height, src_stride, src_corners, |
| num_src_corners, ref, bit_depth, num_inliers_by_motion, |
| params_by_motion, num_motions); |
| case GLOBAL_MOTION_DISFLOW_BASED: |
| return compute_global_motion_disflow_based( |
| type, src_buffer, src_width, src_height, src_stride, src_corners, |
| num_src_corners, ref, bit_depth, num_inliers_by_motion, |
| params_by_motion, num_motions); |
| default: assert(0 && "Unknown global motion estimation type"); |
| } |
| return 0; |
| } |