libavutil/detection_bbox.h

   1 /*
   2  * This file is part of FFmpeg.
   3  *
   4  * FFmpeg is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * FFmpeg is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with FFmpeg; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  17  */
  18
  19 #ifndef AVUTIL_DETECTION_BBOX_H
  20 #define AVUTIL_DETECTION_BBOX_H
  21
  22 #include "rational.h"
  23 #include "avassert.h"
  24 #include "frame.h"
  25
  26 typedef struct AVDetectionBBox {
  27     /**
  28      * Distance in pixels from the left/top edge of the frame,
  29      * together with width and height, defining the bounding box.
  30      */
  31     int x;
  32     int y;
  33     int w;
  34     int h;
  35
  36 #define AV_DETECTION_BBOX_LABEL_NAME_MAX_SIZE 64
  37
  38     /**
  39      * Detect result with confidence
  40      */
  41     char detect_label[AV_DETECTION_BBOX_LABEL_NAME_MAX_SIZE];
  42     AVRational detect_confidence;
  43
  44     /**
  45      * At most 4 classifications based on the detected bounding box.
  46      * For example, we can get max 4 different attributes with 4 different
  47      * DNN models on one bounding box.
  48      * classify_count is zero if no classification.
  49      */
  50 #define AV_NUM_DETECTION_BBOX_CLASSIFY 4
  51     uint32_t classify_count;
  52     char classify_labels[AV_NUM_DETECTION_BBOX_CLASSIFY][AV_DETECTION_BBOX_LABEL_NAME_MAX_SIZE];
  53     AVRational classify_confidences[AV_NUM_DETECTION_BBOX_CLASSIFY];
  54 } AVDetectionBBox;
  55
  56 typedef struct AVDetectionBBoxHeader {
  57     /**
  58      * Information about how the bounding box is generated.
  59      * for example, the DNN model name.
  60      */
  61     char source[256];
  62
  63     /**
  64      * Number of bounding boxes in the array.
  65      */
  66     uint32_t nb_bboxes;
  67
  68     /**
  69      * Offset in bytes from the beginning of this structure at which
  70      * the array of bounding boxes starts.
  71      */
  72     size_t bboxes_offset;
  73
  74     /**
  75      * Size of each bounding box in bytes.
  76      */
  77     size_t bbox_size;
  78 } AVDetectionBBoxHeader;
  79
  80 /*
  81  * Get the bounding box at the specified {@code idx}. Must be between 0 and nb_bboxes.
  82  */
  83 static av_always_inline AVDetectionBBox *
  84 av_get_detection_bbox(const AVDetectionBBoxHeader *header, unsigned int idx)
  85 {
  86     av_assert0(idx < header->nb_bboxes);
  87     return (AVDetectionBBox *)((uint8_t *)header + header->bboxes_offset +
  88                                idx * header->bbox_size);
  89 }
  90
  91 /**
  92  * Allocates memory for AVDetectionBBoxHeader, plus an array of {@code nb_bboxes}
  93  * AVDetectionBBox, and initializes the variables.
  94  * Can be freed with a normal av_free() call.
  95  *
  96  * @param nb_bboxes number of AVDetectionBBox structures to allocate
  97  * @param out_size if non-NULL, the size in bytes of the resulting data array is
  98  * written here.
  99  */
 100 AVDetectionBBoxHeader *av_detection_bbox_alloc(uint32_t nb_bboxes, size_t *out_size);
 101
 102 /**
 103  * Allocates memory for AVDetectionBBoxHeader, plus an array of {@code nb_bboxes}
 104  * AVDetectionBBox, in the given AVFrame {@code frame} as AVFrameSideData of type
 105  * AV_FRAME_DATA_DETECTION_BBOXES and initializes the variables.
 106  */
 107 AVDetectionBBoxHeader *av_detection_bbox_create_side_data(AVFrame *frame, uint32_t nb_bboxes);
 108 #endif