diff options
Diffstat (limited to 'media/libvpx/libvpx/vp9/encoder/vp9_skin_detection.c')
-rw-r--r-- | media/libvpx/libvpx/vp9/encoder/vp9_skin_detection.c | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/media/libvpx/libvpx/vp9/encoder/vp9_skin_detection.c b/media/libvpx/libvpx/vp9/encoder/vp9_skin_detection.c new file mode 100644 index 0000000000..cc6c967767 --- /dev/null +++ b/media/libvpx/libvpx/vp9/encoder/vp9_skin_detection.c @@ -0,0 +1,174 @@ +/* + * Copyright (c) 2015 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 <limits.h> +#include <math.h> + +#include "vp9/common/vp9_blockd.h" +#include "vp9/encoder/vp9_encoder.h" +#include "vp9/encoder/vp9_skin_detection.h" + +int vp9_compute_skin_block(const uint8_t *y, const uint8_t *u, const uint8_t *v, + int stride, int strideuv, int bsize, + int consec_zeromv, int curr_motion_magn) { + // No skin if block has been zero/small motion for long consecutive time. + if (consec_zeromv > 60 && curr_motion_magn == 0) { + return 0; + } else { + int motion = 1; + // Take center pixel in block to determine is_skin. + const int y_width_shift = (4 << b_width_log2_lookup[bsize]) >> 1; + const int y_height_shift = (4 << b_height_log2_lookup[bsize]) >> 1; + const int uv_width_shift = y_width_shift >> 1; + const int uv_height_shift = y_height_shift >> 1; + const uint8_t ysource = y[y_height_shift * stride + y_width_shift]; + const uint8_t usource = u[uv_height_shift * strideuv + uv_width_shift]; + const uint8_t vsource = v[uv_height_shift * strideuv + uv_width_shift]; + + if (consec_zeromv > 25 && curr_motion_magn == 0) motion = 0; + return vpx_skin_pixel(ysource, usource, vsource, motion); + } +} + +void vp9_compute_skin_sb(VP9_COMP *const cpi, BLOCK_SIZE bsize, int mi_row, + int mi_col) { + int i, j, num_bl; + VP9_COMMON *const cm = &cpi->common; + const uint8_t *src_y = cpi->Source->y_buffer; + const uint8_t *src_u = cpi->Source->u_buffer; + const uint8_t *src_v = cpi->Source->v_buffer; + const int src_ystride = cpi->Source->y_stride; + const int src_uvstride = cpi->Source->uv_stride; + const int y_bsize = 4 << b_width_log2_lookup[bsize]; + const int uv_bsize = y_bsize >> 1; + const int shy = (y_bsize == 8) ? 3 : 4; + const int shuv = shy - 1; + const int fac = y_bsize / 8; + const int y_shift = src_ystride * (mi_row << 3) + (mi_col << 3); + const int uv_shift = src_uvstride * (mi_row << 2) + (mi_col << 2); + const int mi_row_limit = VPXMIN(mi_row + 8, cm->mi_rows - 2); + const int mi_col_limit = VPXMIN(mi_col + 8, cm->mi_cols - 2); + src_y += y_shift; + src_u += uv_shift; + src_v += uv_shift; + + for (i = mi_row; i < mi_row_limit; i += fac) { + num_bl = 0; + for (j = mi_col; j < mi_col_limit; j += fac) { + int consec_zeromv = 0; + int bl_index = i * cm->mi_cols + j; + int bl_index1 = bl_index + 1; + int bl_index2 = bl_index + cm->mi_cols; + int bl_index3 = bl_index2 + 1; + // Don't detect skin on the boundary. + if (i == 0 || j == 0) continue; + if (bsize == BLOCK_8X8) + consec_zeromv = cpi->consec_zero_mv[bl_index]; + else + consec_zeromv = VPXMIN(cpi->consec_zero_mv[bl_index], + VPXMIN(cpi->consec_zero_mv[bl_index1], + VPXMIN(cpi->consec_zero_mv[bl_index2], + cpi->consec_zero_mv[bl_index3]))); + cpi->skin_map[bl_index] = + vp9_compute_skin_block(src_y, src_u, src_v, src_ystride, src_uvstride, + bsize, consec_zeromv, 0); + num_bl++; + src_y += y_bsize; + src_u += uv_bsize; + src_v += uv_bsize; + } + src_y += (src_ystride << shy) - (num_bl << shy); + src_u += (src_uvstride << shuv) - (num_bl << shuv); + src_v += (src_uvstride << shuv) - (num_bl << shuv); + } + + // Remove isolated skin blocks (none of its neighbors are skin) and isolated + // non-skin blocks (all of its neighbors are skin). + // Skip 4 corner blocks which have only 3 neighbors to remove isolated skin + // blocks. Skip superblock borders to remove isolated non-skin blocks. + for (i = mi_row; i < mi_row_limit; i += fac) { + for (j = mi_col; j < mi_col_limit; j += fac) { + int bl_index = i * cm->mi_cols + j; + int num_neighbor = 0; + int mi, mj; + int non_skin_threshold = 8; + // Skip 4 corners. + if ((i == mi_row && (j == mi_col || j == mi_col_limit - fac)) || + (i == mi_row_limit - fac && (j == mi_col || j == mi_col_limit - fac))) + continue; + // There are only 5 neighbors for non-skin blocks on the border. + if (i == mi_row || i == mi_row_limit - fac || j == mi_col || + j == mi_col_limit - fac) + non_skin_threshold = 5; + + for (mi = -fac; mi <= fac; mi += fac) { + for (mj = -fac; mj <= fac; mj += fac) { + if (i + mi >= mi_row && i + mi < mi_row_limit && j + mj >= mi_col && + j + mj < mi_col_limit) { + int bl_neighbor_index = (i + mi) * cm->mi_cols + j + mj; + if (cpi->skin_map[bl_neighbor_index]) num_neighbor++; + } + } + } + + if (cpi->skin_map[bl_index] && num_neighbor < 2) + cpi->skin_map[bl_index] = 0; + if (!cpi->skin_map[bl_index] && num_neighbor == non_skin_threshold) + cpi->skin_map[bl_index] = 1; + } + } +} + +#ifdef OUTPUT_YUV_SKINMAP +// For viewing skin map on input source. +void vp9_output_skin_map(VP9_COMP *const cpi, FILE *yuv_skinmap_file) { + int i, j, mi_row, mi_col, num_bl; + VP9_COMMON *const cm = &cpi->common; + uint8_t *y; + const uint8_t *src_y = cpi->Source->y_buffer; + const int src_ystride = cpi->Source->y_stride; + const int y_bsize = 16; // Use 8x8 or 16x16. + const int shy = (y_bsize == 8) ? 3 : 4; + const int fac = y_bsize / 8; + + YV12_BUFFER_CONFIG skinmap; + memset(&skinmap, 0, sizeof(YV12_BUFFER_CONFIG)); + if (vpx_alloc_frame_buffer(&skinmap, cm->width, cm->height, cm->subsampling_x, + cm->subsampling_y, VP9_ENC_BORDER_IN_PIXELS, + cm->byte_alignment)) { + vpx_free_frame_buffer(&skinmap); + return; + } + memset(skinmap.buffer_alloc, 128, skinmap.frame_size); + y = skinmap.y_buffer; + // Loop through blocks and set skin map based on center pixel of block. + // Set y to white for skin block, otherwise set to source with gray scale. + // Ignore rightmost/bottom boundary blocks. + for (mi_row = 0; mi_row < cm->mi_rows - 1; mi_row += fac) { + num_bl = 0; + for (mi_col = 0; mi_col < cm->mi_cols - 1; mi_col += fac) { + const int block_index = mi_row * cm->mi_cols + mi_col; + const int is_skin = cpi->skin_map[block_index]; + for (i = 0; i < y_bsize; i++) { + for (j = 0; j < y_bsize; j++) { + y[i * src_ystride + j] = is_skin ? 255 : src_y[i * src_ystride + j]; + } + } + num_bl++; + y += y_bsize; + src_y += y_bsize; + } + y += (src_ystride << shy) - (num_bl << shy); + src_y += (src_ystride << shy) - (num_bl << shy); + } + vpx_write_yuv_frame(yuv_skinmap_file, &skinmap); + vpx_free_frame_buffer(&skinmap); +} +#endif |