diff options
Diffstat (limited to 'media/libvpx/libvpx/vp8/decoder/error_concealment.c')
| -rw-r--r-- | media/libvpx/libvpx/vp8/decoder/error_concealment.c | 482 |
1 files changed, 482 insertions, 0 deletions
diff --git a/media/libvpx/libvpx/vp8/decoder/error_concealment.c b/media/libvpx/libvpx/vp8/decoder/error_concealment.c new file mode 100644 index 0000000000..85982e4de3 --- /dev/null +++ b/media/libvpx/libvpx/vp8/decoder/error_concealment.c @@ -0,0 +1,482 @@ +/* + * 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); + } + } +} + +static void 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) { + 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; +} |