ref: f8c416f7bb32c781434bce40af9b86cf3e73b82f
dir: /vp8/common/vp8_skin_detection.c/
/* * 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 "vp8/common/alloccommon.h" #include "vp8/common/vp8_skin_detection.h" #include "vpx_dsp/vpx_dsp_common.h" #include "vpx_mem/vpx_mem.h" #include "vpx_util/vpx_write_yuv_frame.h" static int avg_2x2(const uint8_t *s, int p) { int i, j; int sum = 0; for (i = 0; i < 2; ++i, s += p) { for (j = 0; j < 2; ++j) { sum += s[j]; } } return (sum + 2) >> 2; } int vp8_compute_skin_block(const uint8_t *y, const uint8_t *u, const uint8_t *v, int stride, int strideuv, SKIN_DETECTION_BLOCK_SIZE 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; if (consec_zeromv > 25 && curr_motion_magn == 0) motion = 0; if (bsize == SKIN_16X16) { // Take the average of center 2x2 pixels. const int ysource = avg_2x2(y + 7 * stride + 7, stride); const int usource = avg_2x2(u + 3 * strideuv + 3, strideuv); const int vsource = avg_2x2(v + 3 * strideuv + 3, strideuv); return vpx_skin_pixel(ysource, usource, vsource, motion); } else { int num_skin = 0; int i, j; for (i = 0; i < 2; i++) { for (j = 0; j < 2; j++) { // Take the average of center 2x2 pixels. const int ysource = avg_2x2(y + 3 * stride + 3, stride); const int usource = avg_2x2(u + strideuv + 1, strideuv); const int vsource = avg_2x2(v + strideuv + 1, strideuv); num_skin += vpx_skin_pixel(ysource, usource, vsource, motion); if (num_skin >= 2) return 1; y += 8; u += 4; v += 4; } y += (stride << 3) - 16; u += (strideuv << 2) - 8; v += (strideuv << 2) - 8; } return 0; } } } #ifdef OUTPUT_YUV_SKINMAP // For viewing skin map on input source. void vp8_compute_skin_map(VP8_COMP *const cpi, FILE *yuv_skinmap_file) { int i, j, mb_row, mb_col, num_bl; VP8_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; int offset = 0; YV12_BUFFER_CONFIG skinmap; memset(&skinmap, 0, sizeof(skinmap)); if (vp8_yv12_alloc_frame_buffer(&skinmap, cm->Width, cm->Height, VP8BORDERINPIXELS) < 0) { 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. for (mb_row = 0; mb_row < cm->mb_rows; mb_row += 1) { num_bl = 0; for (mb_col = 0; mb_col < cm->mb_cols; mb_col += 1) { const int is_skin = cpi->skin_map[offset++]; for (i = 0; i < 16; i++) { for (j = 0; j < 16; j++) { y[i * src_ystride + j] = is_skin ? 255 : src_y[i * src_ystride + j]; } } num_bl++; y += 16; src_y += 16; } y += (src_ystride << 4) - (num_bl << 4); src_y += (src_ystride << 4) - (num_bl << 4); } vpx_write_yuv_frame(yuv_skinmap_file, &skinmap); vpx_free_frame_buffer(&skinmap); } #endif // OUTPUT_YUV_SKINMAP