libavutil/video_hint.c

   1 /*
   2  * Copyright 2023 Elias Carotti <eliascrt at amazon dot it>
   3  *
   4  * This file is part of FFmpeg.
   5  *
   6  * FFmpeg is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * FFmpeg is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with FFmpeg; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #include <string.h>
  22
  23 #include "avstring.h"
  24 #include "frame.h"
  25 #include "macros.h"
  26 #include "mem.h"
  27 #include "video_hint.h"
  28
  29 AVVideoHint *av_video_hint_alloc(size_t nb_rects,
  30                                  size_t *out_size)
  31 {
  32     struct TestStruct {
  33         AVVideoHint hint;
  34         AVVideoRect rect;
  35     };
  36     const size_t rect_offset = offsetof(struct TestStruct, rect);
  37     size_t size = rect_offset;
  38     AVVideoHint *hint;
  39
  40     *out_size = 0;
  41     if (nb_rects > (SIZE_MAX - size) / sizeof(AVVideoRect))
  42         return NULL;
  43     size += sizeof(AVVideoRect) * nb_rects;
  44
  45     hint = av_mallocz(size);
  46     if (!hint)
  47         return NULL;
  48
  49     hint->nb_rects    = nb_rects;
  50     hint->rect_offset = rect_offset;
  51     hint->rect_size   = sizeof(AVVideoRect);
  52
  53     *out_size = size;
  54
  55     return hint;
  56 }
  57
  58 AVVideoHint *av_video_hint_create_side_data(AVFrame *frame,
  59                                             size_t nb_rects)
  60 {
  61     AVVideoHint *hint;
  62     AVBufferRef *buf;
  63     size_t size = 0;
  64
  65     hint = av_video_hint_alloc(nb_rects, &size);
  66     if (!hint)
  67         return NULL;
  68
  69     buf = av_buffer_create((uint8_t *)hint, size, NULL, NULL, 0);
  70     if (!buf) {
  71         av_freep(&hint);
  72         return NULL;
  73     }
  74
  75     if (!av_frame_new_side_data_from_buf(frame, AV_FRAME_DATA_VIDEO_HINT, buf)) {
  76         av_buffer_unref(&buf);
  77         return NULL;
  78     }
  79
  80     return hint;
  81 }