chromium / webm / libvpx / b4e0986391819a33c71795b2dd76710104761b52 / . / 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); | |

} | |

} | |

} | |

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; | |

} |