ref: d98bd7cc5f8bad1b969590c8343ef0e4e2b89e89
dir: /vp8/decoder/error_concealment.c/
/* * Copyright (c) 2011 The WebM project authors. All Rights Reserved. * * Use of this source code is governed by a BSD-style license * that can be found in the LICENSE file in the root of the source * tree. An additional intellectual property rights grant can be found * in the file PATENTS. All contributing project authors may * be found in the AUTHORS file in the root of the source tree. */ #include <assert.h> #include "error_concealment.h" #include "onyxd_int.h" #include "decodemv.h" #include "vpx_mem/vpx_mem.h" #include "vp8/common/findnearmv.h" #include "vp8/common/common.h" #include "vpx_dsp/vpx_dsp_common.h" #define FLOOR(x, q) ((x) & -(1 << (q))) #define NUM_NEIGHBORS 20 typedef struct ec_position { int row; int col; } EC_POS; /* * Regenerate the table in Matlab with: * x = meshgrid((1:4), (1:4)); * y = meshgrid((1:4), (1:4))'; * W = round((1./(sqrt(x.^2 + y.^2))*2^7)); * W(1,1) = 0; */ static const int weights_q7[5][5] = { { 0, 128, 64, 43, 32 }, { 128, 91, 57, 40, 31 }, { 64, 57, 45, 36, 29 }, { 43, 40, 36, 30, 26 }, { 32, 31, 29, 26, 23 } }; int vp8_alloc_overlap_lists(VP8D_COMP *pbi) { if (pbi->overlaps != NULL) { vpx_free(pbi->overlaps); pbi->overlaps = NULL; } pbi->overlaps = vpx_calloc(pbi->common.mb_rows * pbi->common.mb_cols, sizeof(MB_OVERLAP)); if (pbi->overlaps == NULL) return -1; return 0; } void vp8_de_alloc_overlap_lists(VP8D_COMP *pbi) { vpx_free(pbi->overlaps); pbi->overlaps = NULL; } /* Inserts a new overlap area value to the list of overlaps of a block */ static void assign_overlap(OVERLAP_NODE *overlaps, union b_mode_info *bmi, int overlap) { int i; if (overlap <= 0) return; /* Find and assign to the next empty overlap node in the list of overlaps. * Empty is defined as bmi == NULL */ for (i = 0; i < MAX_OVERLAPS; ++i) { if (overlaps[i].bmi == NULL) { overlaps[i].bmi = bmi; overlaps[i].overlap = overlap; break; } } } /* Calculates the overlap area between two 4x4 squares, where the first * square has its upper-left corner at (b1_row, b1_col) and the second * square has its upper-left corner at (b2_row, b2_col). Doesn't * properly handle squares which do not overlap. */ static int block_overlap(int b1_row, int b1_col, int b2_row, int b2_col) { const int int_top = VPXMAX(b1_row, b2_row); // top const int int_left = VPXMAX(b1_col, b2_col); // left /* Since each block is 4x4 pixels, adding 4 (Q3) to the left/top edge * gives us the right/bottom edge. */ const int int_right = VPXMIN(b1_col + (4 << 3), b2_col + (4 << 3)); // right const int int_bottom = VPXMIN(b1_row + (4 << 3), b2_row + (4 << 3)); // bottom return (int_bottom - int_top) * (int_right - int_left); } /* Calculates the overlap area for all blocks in a macroblock at position * (mb_row, mb_col) in macroblocks, which are being overlapped by a given * overlapping block at position (new_row, new_col) (in pixels, Q3). The * first block being overlapped in the macroblock has position (first_blk_row, * first_blk_col) in blocks relative the upper-left corner of the image. */ static void calculate_overlaps_mb(B_OVERLAP *b_overlaps, union b_mode_info *bmi, int new_row, int new_col, int mb_row, int mb_col, int first_blk_row, int first_blk_col) { /* Find the blocks within this MB (defined by mb_row, mb_col) which are * overlapped by bmi and calculate and assign overlap for each of those * blocks. */ /* Block coordinates relative the upper-left block */ const int rel_ol_blk_row = first_blk_row - mb_row * 4; const int rel_ol_blk_col = first_blk_col - mb_col * 4; /* If the block partly overlaps any previous MB, these coordinates * can be < 0. We don't want to access blocks in previous MBs. */ const int blk_idx = VPXMAX(rel_ol_blk_row, 0) * 4 + VPXMAX(rel_ol_blk_col, 0); /* Upper left overlapping block */ B_OVERLAP *b_ol_ul = &(b_overlaps[blk_idx]); /* Calculate and assign overlaps for all blocks in this MB * which the motion compensated block overlaps */ /* Avoid calculating overlaps for blocks in later MBs */ int end_row = VPXMIN(4 + mb_row * 4 - first_blk_row, 2); int end_col = VPXMIN(4 + mb_col * 4 - first_blk_col, 2); int row, col; /* Check if new_row and new_col are evenly divisible by 4 (Q3), * and if so we shouldn't check neighboring blocks */ if (new_row >= 0 && (new_row & 0x1F) == 0) end_row = 1; if (new_col >= 0 && (new_col & 0x1F) == 0) end_col = 1; /* Check if the overlapping block partly overlaps a previous MB * and if so, we're overlapping fewer blocks in this MB. */ if (new_row < (mb_row * 16) << 3) end_row = 1; if (new_col < (mb_col * 16) << 3) end_col = 1; for (row = 0; row < end_row; ++row) { for (col = 0; col < end_col; ++col) { /* input in Q3, result in Q6 */ const int overlap = block_overlap(new_row, new_col, (((first_blk_row + row) * 4) << 3), (((first_blk_col + col) * 4) << 3)); assign_overlap(b_ol_ul[row * 4 + col].overlaps, bmi, overlap); } } } void vp8_calculate_overlaps(MB_OVERLAP *overlap_ul, int mb_rows, int mb_cols, union b_mode_info *bmi, int b_row, int b_col) { MB_OVERLAP *mb_overlap; int row, col, rel_row, rel_col; int new_row, new_col; int end_row, end_col; int overlap_b_row, overlap_b_col; int overlap_mb_row, overlap_mb_col; /* mb subpixel position */ row = (4 * b_row) << 3; /* Q3 */ col = (4 * b_col) << 3; /* Q3 */ /* reverse compensate for motion */ new_row = row - bmi->mv.as_mv.row; new_col = col - bmi->mv.as_mv.col; if (new_row >= ((16 * mb_rows) << 3) || new_col >= ((16 * mb_cols) << 3)) { /* the new block ended up outside the frame */ return; } if (new_row <= -32 || new_col <= -32) { /* outside the frame */ return; } /* overlapping block's position in blocks */ overlap_b_row = FLOOR(new_row / 4, 3) >> 3; overlap_b_col = FLOOR(new_col / 4, 3) >> 3; /* overlapping block's MB position in MBs * operations are done in Q3 */ overlap_mb_row = FLOOR((overlap_b_row << 3) / 4, 3) >> 3; overlap_mb_col = FLOOR((overlap_b_col << 3) / 4, 3) >> 3; end_row = VPXMIN(mb_rows - overlap_mb_row, 2); end_col = VPXMIN(mb_cols - overlap_mb_col, 2); /* Don't calculate overlap for MBs we don't overlap */ /* Check if the new block row starts at the last block row of the MB */ if (abs(new_row - ((16 * overlap_mb_row) << 3)) < ((3 * 4) << 3)) end_row = 1; /* Check if the new block col starts at the last block col of the MB */ if (abs(new_col - ((16 * overlap_mb_col) << 3)) < ((3 * 4) << 3)) end_col = 1; /* find the MB(s) this block is overlapping */ for (rel_row = 0; rel_row < end_row; ++rel_row) { for (rel_col = 0; rel_col < end_col; ++rel_col) { if (overlap_mb_row + rel_row < 0 || overlap_mb_col + rel_col < 0) continue; mb_overlap = overlap_ul + (overlap_mb_row + rel_row) * mb_cols + overlap_mb_col + rel_col; calculate_overlaps_mb(mb_overlap->overlaps, bmi, new_row, new_col, overlap_mb_row + rel_row, overlap_mb_col + rel_col, overlap_b_row + rel_row, overlap_b_col + rel_col); } } } /* Estimates a motion vector given the overlapping blocks' motion vectors. * Filters out all overlapping blocks which do not refer to the correct * reference frame type. */ static void estimate_mv(const OVERLAP_NODE *overlaps, union b_mode_info *bmi) { int i; int overlap_sum = 0; int row_acc = 0; int col_acc = 0; bmi->mv.as_int = 0; for (i = 0; i < MAX_OVERLAPS; ++i) { if (overlaps[i].bmi == NULL) break; col_acc += overlaps[i].overlap * overlaps[i].bmi->mv.as_mv.col; row_acc += overlaps[i].overlap * overlaps[i].bmi->mv.as_mv.row; overlap_sum += overlaps[i].overlap; } if (overlap_sum > 0) { /* Q9 / Q6 = Q3 */ bmi->mv.as_mv.col = col_acc / overlap_sum; bmi->mv.as_mv.row = row_acc / overlap_sum; } else { bmi->mv.as_mv.col = 0; bmi->mv.as_mv.row = 0; } } /* Estimates all motion vectors for a macroblock given the lists of * overlaps for each block. Decides whether or not the MVs must be clamped. */ static void estimate_mb_mvs(const B_OVERLAP *block_overlaps, MODE_INFO *mi, int mb_to_left_edge, int mb_to_right_edge, int mb_to_top_edge, int mb_to_bottom_edge) { int row, col; int non_zero_count = 0; MV *const filtered_mv = &(mi->mbmi.mv.as_mv); union b_mode_info *const bmi = mi->bmi; filtered_mv->col = 0; filtered_mv->row = 0; mi->mbmi.need_to_clamp_mvs = 0; for (row = 0; row < 4; ++row) { int this_b_to_top_edge = mb_to_top_edge + ((row * 4) << 3); int this_b_to_bottom_edge = mb_to_bottom_edge - ((row * 4) << 3); for (col = 0; col < 4; ++col) { int i = row * 4 + col; int this_b_to_left_edge = mb_to_left_edge + ((col * 4) << 3); int this_b_to_right_edge = mb_to_right_edge - ((col * 4) << 3); /* Estimate vectors for all blocks which are overlapped by this */ /* type. Interpolate/extrapolate the rest of the block's MVs */ estimate_mv(block_overlaps[i].overlaps, &(bmi[i])); mi->mbmi.need_to_clamp_mvs |= vp8_check_mv_bounds( &bmi[i].mv, this_b_to_left_edge, this_b_to_right_edge, this_b_to_top_edge, this_b_to_bottom_edge); if (bmi[i].mv.as_int != 0) { ++non_zero_count; filtered_mv->col += bmi[i].mv.as_mv.col; filtered_mv->row += bmi[i].mv.as_mv.row; } } } if (non_zero_count > 0) { filtered_mv->col /= non_zero_count; filtered_mv->row /= non_zero_count; } } static void calc_prev_mb_overlaps(MB_OVERLAP *overlaps, MODE_INFO *prev_mi, int mb_row, int mb_col, int mb_rows, int mb_cols) { int sub_row; int sub_col; for (sub_row = 0; sub_row < 4; ++sub_row) { for (sub_col = 0; sub_col < 4; ++sub_col) { vp8_calculate_overlaps(overlaps, mb_rows, mb_cols, &(prev_mi->bmi[sub_row * 4 + sub_col]), 4 * mb_row + sub_row, 4 * mb_col + sub_col); } } } /* Estimate all missing motion vectors. This function does the same as the one * above, but has different input arguments. */ static void estimate_missing_mvs(MB_OVERLAP *overlaps, MODE_INFO *mi, MODE_INFO *prev_mi, int mb_rows, int mb_cols, unsigned int first_corrupt) { int mb_row, mb_col; memset(overlaps, 0, sizeof(MB_OVERLAP) * mb_rows * mb_cols); /* First calculate the overlaps for all blocks */ for (mb_row = 0; mb_row < mb_rows; ++mb_row) { for (mb_col = 0; mb_col < mb_cols; ++mb_col) { /* We're only able to use blocks referring to the last frame * when extrapolating new vectors. */ if (prev_mi->mbmi.ref_frame == LAST_FRAME) { calc_prev_mb_overlaps(overlaps, prev_mi, mb_row, mb_col, mb_rows, mb_cols); } ++prev_mi; } ++prev_mi; } mb_row = first_corrupt / mb_cols; mb_col = first_corrupt - mb_row * mb_cols; mi += mb_row * (mb_cols + 1) + mb_col; /* Go through all macroblocks in the current image with missing MVs * and calculate new MVs using the overlaps. */ for (; mb_row < mb_rows; ++mb_row) { int mb_to_top_edge = -((mb_row * 16)) << 3; int mb_to_bottom_edge = ((mb_rows - 1 - mb_row) * 16) << 3; for (; mb_col < mb_cols; ++mb_col) { int mb_to_left_edge = -((mb_col * 16) << 3); int mb_to_right_edge = ((mb_cols - 1 - mb_col) * 16) << 3; const B_OVERLAP *block_overlaps = overlaps[mb_row * mb_cols + mb_col].overlaps; mi->mbmi.ref_frame = LAST_FRAME; mi->mbmi.mode = SPLITMV; mi->mbmi.uv_mode = DC_PRED; mi->mbmi.partitioning = 3; mi->mbmi.segment_id = 0; estimate_mb_mvs(block_overlaps, mi, mb_to_left_edge, mb_to_right_edge, mb_to_top_edge, mb_to_bottom_edge); ++mi; } mb_col = 0; ++mi; } } void vp8_estimate_missing_mvs(VP8D_COMP *pbi) { VP8_COMMON *const pc = &pbi->common; estimate_missing_mvs(pbi->overlaps, pc->mi, pc->prev_mi, pc->mb_rows, pc->mb_cols, pbi->mvs_corrupt_from_mb); } static void assign_neighbor(EC_BLOCK *neighbor, MODE_INFO *mi, int block_idx) { assert(mi->mbmi.ref_frame < MAX_REF_FRAMES); neighbor->ref_frame = mi->mbmi.ref_frame; neighbor->mv = mi->bmi[block_idx].mv.as_mv; } /* Finds the neighboring blocks of a macroblocks. In the general case * 20 blocks are found. If a fewer number of blocks are found due to * image boundaries, those positions in the EC_BLOCK array are left "empty". * The neighbors are enumerated with the upper-left neighbor as the first * element, the second element refers to the neighbor to right of the previous * neighbor, and so on. The last element refers to the neighbor below the first * neighbor. */ static void find_neighboring_blocks(MODE_INFO *mi, EC_BLOCK *neighbors, int mb_row, int mb_col, int mb_rows, int mb_cols, int mi_stride) { int i = 0; int j; if (mb_row > 0) { /* upper left */ if (mb_col > 0) assign_neighbor(&neighbors[i], mi - mi_stride - 1, 15); ++i; /* above */ for (j = 12; j < 16; ++j, ++i) assign_neighbor(&neighbors[i], mi - mi_stride, j); } else i += 5; if (mb_col < mb_cols - 1) { /* upper right */ if (mb_row > 0) assign_neighbor(&neighbors[i], mi - mi_stride + 1, 12); ++i; /* right */ for (j = 0; j <= 12; j += 4, ++i) assign_neighbor(&neighbors[i], mi + 1, j); } else i += 5; if (mb_row < mb_rows - 1) { /* lower right */ if (mb_col < mb_cols - 1) assign_neighbor(&neighbors[i], mi + mi_stride + 1, 0); ++i; /* below */ for (j = 0; j < 4; ++j, ++i) assign_neighbor(&neighbors[i], mi + mi_stride, j); } else i += 5; if (mb_col > 0) { /* lower left */ if (mb_row < mb_rows - 1) assign_neighbor(&neighbors[i], mi + mi_stride - 1, 4); ++i; /* left */ for (j = 3; j < 16; j += 4, ++i) { assign_neighbor(&neighbors[i], mi - 1, j); } } else i += 5; assert(i == 20); } /* Interpolates all motion vectors for a macroblock from the neighboring blocks' * motion vectors. */ static void interpolate_mvs(MACROBLOCKD *mb, EC_BLOCK *neighbors, MV_REFERENCE_FRAME dom_ref_frame) { int row, col, i; MODE_INFO *const mi = mb->mode_info_context; /* Table with the position of the neighboring blocks relative the position * of the upper left block of the current MB. Starting with the upper left * neighbor and going to the right. */ const EC_POS neigh_pos[NUM_NEIGHBORS] = { { -1, -1 }, { -1, 0 }, { -1, 1 }, { -1, 2 }, { -1, 3 }, { -1, 4 }, { 0, 4 }, { 1, 4 }, { 2, 4 }, { 3, 4 }, { 4, 4 }, { 4, 3 }, { 4, 2 }, { 4, 1 }, { 4, 0 }, { 4, -1 }, { 3, -1 }, { 2, -1 }, { 1, -1 }, { 0, -1 } }; mi->mbmi.need_to_clamp_mvs = 0; for (row = 0; row < 4; ++row) { int mb_to_top_edge = mb->mb_to_top_edge + ((row * 4) << 3); int mb_to_bottom_edge = mb->mb_to_bottom_edge - ((row * 4) << 3); for (col = 0; col < 4; ++col) { int mb_to_left_edge = mb->mb_to_left_edge + ((col * 4) << 3); int mb_to_right_edge = mb->mb_to_right_edge - ((col * 4) << 3); int w_sum = 0; int mv_row_sum = 0; int mv_col_sum = 0; int_mv *const mv = &(mi->bmi[row * 4 + col].mv); mv->as_int = 0; for (i = 0; i < NUM_NEIGHBORS; ++i) { /* Calculate the weighted sum of neighboring MVs referring * to the dominant frame type. */ const int w = weights_q7[abs(row - neigh_pos[i].row)] [abs(col - neigh_pos[i].col)]; if (neighbors[i].ref_frame != dom_ref_frame) continue; w_sum += w; /* Q7 * Q3 = Q10 */ mv_row_sum += w * neighbors[i].mv.row; mv_col_sum += w * neighbors[i].mv.col; } if (w_sum > 0) { /* Avoid division by zero. * Normalize with the sum of the coefficients * Q3 = Q10 / Q7 */ mv->as_mv.row = mv_row_sum / w_sum; mv->as_mv.col = mv_col_sum / w_sum; mi->mbmi.need_to_clamp_mvs |= vp8_check_mv_bounds(mv, mb_to_left_edge, mb_to_right_edge, mb_to_top_edge, mb_to_bottom_edge); } } } } void vp8_interpolate_motion(MACROBLOCKD *mb, int mb_row, int mb_col, int mb_rows, int mb_cols) { /* Find relevant neighboring blocks */ EC_BLOCK neighbors[NUM_NEIGHBORS]; int i; /* Initialize the array. MAX_REF_FRAMES is interpreted as "doesn't exist" */ for (i = 0; i < NUM_NEIGHBORS; ++i) { neighbors[i].ref_frame = MAX_REF_FRAMES; neighbors[i].mv.row = neighbors[i].mv.col = 0; } find_neighboring_blocks(mb->mode_info_context, neighbors, mb_row, mb_col, mb_rows, mb_cols, mb->mode_info_stride); /* Interpolate MVs for the missing blocks from the surrounding * blocks which refer to the last frame. */ interpolate_mvs(mb, neighbors, LAST_FRAME); mb->mode_info_context->mbmi.ref_frame = LAST_FRAME; mb->mode_info_context->mbmi.mode = SPLITMV; mb->mode_info_context->mbmi.uv_mode = DC_PRED; mb->mode_info_context->mbmi.partitioning = 3; mb->mode_info_context->mbmi.segment_id = 0; }