ref: 795c9188f2efe156982722187805a420f670f3c1
parent: 0af40df746b47057e3f416fbfc49d83e324741b4
author: Dan Zhu <zxdan@google.com>
date: Wed Aug 14 09:55:08 EDT 2019
smooth motion field Change-Id: I1e8273fa65f7655e49f626863fe457efef23fb54
--- a/vp9/encoder/vp9_non_greedy_mv.c
+++ b/vp9/encoder/vp9_non_greedy_mv.c
@@ -204,3 +204,94 @@
}
return 0;
}
+
+static MV get_smooth_motion_vector(const MV search_mv, const MV *tmp_mf,
+ const int (*M)[4], int rows, int cols,
+ int row, int col, float alpha) {+ const MV tmp_mv = tmp_mf[row * cols + col];
+ int idx_row, idx_col;
+ float avg_nb_mv[2] = { 0.0f, 0.0f };+ MV mv = { 0, 0 };+ float filter[3][3] = { { 1.0f / 12.0f, 1.0f / 6.0f, 1.0f / 12.0f },+ { 1.0f / 6.0f, 0.0f, 1.0f / 6.0f },+ { 1.0f / 12.0f, 1.0f / 6.0f, 1.0f / 12.0f } };+ int ref_row = row + search_mv.row;
+ int ref_col = col + search_mv.col;
+ ref_row = ref_row < 0 ? 0 : (ref_row >= rows ? rows - 1 : ref_row);
+ ref_col = ref_col < 0 ? 0 : (ref_col >= cols ? cols - 1 : ref_col);
+ for (idx_row = 0; idx_row < 3; ++idx_row) {+ int nb_row = row + idx_row - 1;
+ for (idx_col = 0; idx_col < 3; ++idx_col) {+ int nb_col = col + idx_col - 1;
+ if (nb_row < 0 || nb_col < 0 || nb_row >= rows || nb_col >= cols) {+ avg_nb_mv[0] += (tmp_mv.row) * filter[idx_row][idx_col];
+ avg_nb_mv[1] += (tmp_mv.col) * filter[idx_row][idx_col];
+ } else {+ const MV nb_mv = tmp_mf[nb_row * cols + nb_col];
+ avg_nb_mv[0] += (nb_mv.row) * filter[idx_row][idx_col];
+ avg_nb_mv[1] += (nb_mv.col) * filter[idx_row][idx_col];
+ }
+ }
+ }
+ {+ // M is the local variance of reference frame
+ float M00 = M[ref_row * cols + ref_col][0];
+ float M01 = M[ref_row * cols + ref_col][1];
+ float M10 = M[ref_row * cols + ref_col][2];
+ float M11 = M[ref_row * cols + ref_col][3];
+
+ float det = (M00 + alpha) * (M11 + alpha) - M01 * M10;
+
+ float inv_M00 = (M11 + alpha) / det;
+ float inv_M01 = -M01 / det;
+ float inv_M10 = -M10 / det;
+ float inv_M11 = (M00 + alpha) / det;
+
+ float inv_MM00 = inv_M00 * M00 + inv_M01 * M10;
+ float inv_MM01 = inv_M00 * M01 + inv_M01 * M11;
+ float inv_MM10 = inv_M10 * M00 + inv_M11 * M10;
+ float inv_MM11 = inv_M10 * M01 + inv_M11 * M11;
+
+ mv.row = (int)(inv_M00 * avg_nb_mv[0] + inv_M01 * avg_nb_mv[1] +
+ inv_MM00 * search_mv.row + inv_MM01 * search_mv.col);
+ mv.col = (int)(inv_M10 * avg_nb_mv[0] + inv_M11 * avg_nb_mv[1] +
+ inv_MM10 * search_mv.row + inv_MM11 * search_mv.col);
+ }
+ return mv;
+}
+
+void vp9_get_smooth_motion_field(const MV *scaled_search_mf, const int (*M)[4],
+ int rows, int cols, float alpha, int num_iters,
+ MV *smooth_mf) {+ // note: the scaled_search_mf and smooth_mf are all scaled by macroblock size
+ // M is the local variation of reference frame
+ // build two buffers
+ MV *input = (MV *)malloc(rows * cols * sizeof(MV));
+ MV *output = (MV *)malloc(rows * cols * sizeof(MV));
+ int idx;
+ int row, col;
+ // copy search results to input buffer
+ for (idx = 0; idx < rows * cols; ++idx) {+ input[idx] = scaled_search_mf[idx];
+ }
+ for (idx = 0; idx < num_iters; ++idx) {+ MV *tmp;
+ for (row = 0; row < rows; ++row) {+ for (col = 0; col < cols; ++col) {+ output[row * cols + col] =
+ get_smooth_motion_vector(scaled_search_mf[row * cols + col], input,
+ M, rows, cols, row, col, alpha);
+ }
+ }
+ // swap buffers
+ tmp = input;
+ input = output;
+ output = tmp;
+ }
+ // copy smoothed results to output
+ for (idx = 0; idx < rows * cols; ++idx) {+ smooth_mf[idx] = input[idx];
+ }
+ free(input);
+ free(output);
+}
--- a/vp9/encoder/vp9_non_greedy_mv.h
+++ b/vp9/encoder/vp9_non_greedy_mv.h
@@ -14,12 +14,15 @@
#ifdef __cplusplus
extern "C" {#endif
-
#define NB_MVS_NUM 4
#define LOG2_PRECISION 20
int64_t vp9_nb_mvs_inconsistency(const MV *mv, const int_mv *nb_full_mvs,
int mv_num);
+
+void vp9_get_smooth_motion_field(const MV *search_mf, const int (*M)[4],
+ int rows, int cols, float alpha, int num_iters,
+ MV *smooth_mf);
#ifdef __cplusplus
} // extern "C"