Update libvpx snapshot to v0.9.7-p1 (Cayuga).

source/libvpx/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 "error_concealment.h"
+#include "onyxd_int.h"
+#include "decodemv.h"
+#include "vpx_mem/vpx_mem.h"
+#include "vp8/common/recon.h"
+#include "vp8/common/findnearmv.h"
+
+#include <assert.h>
+
+#define MIN(x,y) (((x)<(y))?(x):(y))
+#define MAX(x,y) (((x)>(y))?(x):(y))
+
+#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;
+    vpx_memset(pbi->overlaps, 0,
+               sizeof(MB_OVERLAP) * pbi->common.mb_rows * pbi->common.mb_cols);
+    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 = MAX(b1_row, b2_row); // top
+    const int int_left = MAX(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 = MIN(b1_col + (4<<3), b2_col + (4<<3)); // right
+    const int int_bottom = MIN(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 = MAX(rel_ol_blk_row,0) * 4 + MAX(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 = MIN(4 + mb_row * 4 - first_blk_row, 2);
+    int end_col = MIN(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 <= (-4 << 3) || new_col <= (-4 << 3))
+    {
+        /* 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 = MIN(mb_rows - overlap_mb_row, 2);
+    end_col = MIN(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 i;
+    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;
+    for (i = 0; i < 16; ++i)
+    {
+        /* 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,
+                                                         mb_to_left_edge,
+                                                         mb_to_right_edge,
+                                                         mb_to_top_edge,
+                                                         mb_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;
+    vpx_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);
+}
+
+/* Calculates which reference frame type is dominating among the neighbors */
+static MV_REFERENCE_FRAME dominant_ref_frame(EC_BLOCK *neighbors)
+{
+    /* Default to referring to "skip" */
+    MV_REFERENCE_FRAME dom_ref_frame = LAST_FRAME;
+    int max_ref_frame_cnt = 0;
+    int ref_frame_cnt[MAX_REF_FRAMES] = {0};
+    int i;
+    /* Count neighboring reference frames */
+    for (i = 0; i < NUM_NEIGHBORS; ++i)
+    {
+        if (neighbors[i].ref_frame < MAX_REF_FRAMES &&
+            neighbors[i].ref_frame != INTRA_FRAME)
+            ++ref_frame_cnt[neighbors[i].ref_frame];
+    }
+    /* Find maximum */
+    for (i = 0; i < MAX_REF_FRAMES; ++i)
+    {
+        if (ref_frame_cnt[i] > max_ref_frame_cnt)
+        {
+            dom_ref_frame = i;
+            max_ref_frame_cnt = ref_frame_cnt[i];
+        }
+    }
+    return dom_ref_frame;
+}
+
+/* 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}
+                                      };
+    for (row = 0; row < 4; ++row)
+    {
+        for (col = 0; col < 4; ++col)
+        {
+            int w_sum = 0;
+            int mv_row_sum = 0;
+            int mv_col_sum = 0;
+            int_mv * const mv = &(mi->bmi[row*4 + col].mv);
+            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->mb_to_left_edge,
+                                                       mb->mb_to_right_edge,
+                                                       mb->mb_to_top_edge,
+                                                       mb->mb_to_bottom_edge);
+            }
+            else
+            {
+                mv->as_int = 0;
+                mi->mbmi.need_to_clamp_mvs = 0;
+            }
+        }
+    }
+}
+
+void vp8_interpolate_motion(MACROBLOCKD *mb,
+                        int mb_row, int mb_col,
+                        int mb_rows, int mb_cols,
+                        int mi_stride)
+{
+    /* Find relevant neighboring blocks */
+    EC_BLOCK neighbors[NUM_NEIGHBORS];
+    MV_REFERENCE_FRAME dom_ref_frame;
+    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);
+    /* Determine the dominant block type */
+    dom_ref_frame = dominant_ref_frame(neighbors);
+    /* Interpolate MVs for the missing blocks
+     * from the dominating MVs */
+    interpolate_mvs(mb, neighbors, dom_ref_frame);
+
+    mb->mode_info_context->mbmi.ref_frame = dom_ref_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;
+}
+
+void vp8_conceal_corrupt_mb(MACROBLOCKD *xd)
+{
+    /* This macroblock has corrupt residual, use the motion compensated
+       image (predictor) for concealment */
+    vp8_recon_copy16x16(xd->predictor, 16, xd->dst.y_buffer, xd->dst.y_stride);
+    vp8_recon_copy8x8(xd->predictor + 256, 8,
+                      xd->dst.u_buffer, xd->dst.uv_stride);
+    vp8_recon_copy8x8(xd->predictor + 320, 8,
+                      xd->dst.v_buffer, xd->dst.uv_stride);
+}