/src/libheif/libheif/common_utils.cc

Source
/*
 * HEIF codec.
 * Copyright (c) 2023 Dirk Farin <dirk.farin@gmail.com>
 *
 * This file is part of libheif.
 *
 * libheif is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of
 * the License, or (at your option) any later version.
 *
 * libheif is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with libheif.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "common_utils.h"
#include <cassert>


uint8_t chroma_h_subsampling(heif_chroma c)
{
  switch (c) {
    case heif_chroma_monochrome:
    case heif_chroma_444:
      return 1;

    case heif_chroma_420:
    case heif_chroma_422:
      return 2;

    case heif_chroma_interleaved_RGB:
    case heif_chroma_interleaved_RGBA:
    default:
      assert(false);
      return 0;
  }
}


uint8_t chroma_v_subsampling(heif_chroma c)
{
  switch (c) {
    case heif_chroma_monochrome:
    case heif_chroma_444:
    case heif_chroma_422:
      return 1;

    case heif_chroma_420:
      return 2;

    case heif_chroma_interleaved_RGB:
    case heif_chroma_interleaved_RGBA:
    default:
      assert(false);
      return 0;
  }
}


uint32_t get_subsampled_size_h(uint32_t width,
                               heif_channel channel,
                               heif_chroma chroma,
                               scaling_mode mode)
{
  if (channel == heif_channel_Cb ||
      channel == heif_channel_Cr) {
    uint8_t chromaSubH = chroma_h_subsampling(chroma);

    switch (mode) {
      case scaling_mode::round_up:
        // NOLINTNEXTLINE(clang-analyzer-core.DivideZero)
        return (width + chromaSubH - 1) / chromaSubH;
      case scaling_mode::round_down:
        // NOLINTNEXTLINE(clang-analyzer-core.DivideZero)
        return width / chromaSubH;
      case scaling_mode::is_divisible:
        assert(width % chromaSubH == 0);
        return width / chromaSubH;
      default:
        assert(false);
        return 0;
    }
  } else {
    return width;
  }
}


uint32_t get_subsampled_size_v(uint32_t height,
                               heif_channel channel,
                               heif_chroma chroma,
                               scaling_mode mode)
{
  if (channel == heif_channel_Cb ||
      channel == heif_channel_Cr) {
    uint8_t chromaSubV = chroma_v_subsampling(chroma);

    switch (mode) {
      case scaling_mode::round_up:
        // NOLINTNEXTLINE(clang-analyzer-core.DivideZero)
        return (height + chromaSubV - 1) / chromaSubV;
      case scaling_mode::round_down:
        // NOLINTNEXTLINE(clang-analyzer-core.DivideZero)
        return height / chromaSubV;
      case scaling_mode::is_divisible:
        assert(height % chromaSubV == 0);
        return height / chromaSubV;
      default:
        assert(false);
        return 0;
    }
  } else {
    return height;
  }
}


void get_subsampled_size(uint32_t width, uint32_t height,
                         heif_channel channel,
                         heif_chroma chroma,
                         uint32_t* subsampled_width, uint32_t* subsampled_height)
{
  *subsampled_width = get_subsampled_size_h(width, channel, chroma, scaling_mode::round_up);
  *subsampled_height = get_subsampled_size_v(height, channel, chroma, scaling_mode::round_up);
}



uint8_t compute_avif_profile(int bits_per_pixel, heif_chroma chroma)
{
  if (bits_per_pixel <= 10 &&
      (chroma == heif_chroma_420 ||
       chroma == heif_chroma_monochrome)) {
    return 0;
  }
  else if (bits_per_pixel <= 10 &&
           chroma == heif_chroma_444) {
    return 1;
  }
  else {
    return 2;
  }
}


std::string fourcc_to_string(uint32_t code)
{
  std::string str("    ");
  str[0] = static_cast<char>((code >> 24) & 0xFF);
  str[1] = static_cast<char>((code >> 16) & 0xFF);
  str[2] = static_cast<char>((code >> 8) & 0xFF);
  str[3] = static_cast<char>((code >> 0) & 0xFF);

  return str;
}


Result<std::string> vector_to_string(const std::vector<uint8_t>& vec)
{
  if (vec.empty()) {
    return std::string{}; // return empty string
  }

  if (vec.back() != 0) {
    return Error{heif_error_Invalid_input,
                 heif_suberror_Unspecified,
                 "utf8string not null-terminated"};
  }

  for (size_t i=0;i<vec.size()-1;i++) {
    if (vec[i] == 0) {
      return Error{heif_error_Invalid_input,
                   heif_suberror_Unspecified,
                   "utf8string with null character"};
    }
  }

  return std::string(vec.begin(), vec.end()-1);
}

Line	Count	Source
1		/*
2		* HEIF codec.
3		* Copyright (c) 2023 Dirk Farin <dirk.farin@gmail.com>
4		*
5		* This file is part of libheif.
6		*
7		* libheif is free software: you can redistribute it and/or modify
8		* it under the terms of the GNU Lesser General Public License as
9		* published by the Free Software Foundation, either version 3 of
10		* the License, or (at your option) any later version.
11		*
12		* libheif is distributed in the hope that it will be useful,
13		* but WITHOUT ANY WARRANTY; without even the implied warranty of
14		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15		* GNU Lesser General Public License for more details.
16		*
17		* You should have received a copy of the GNU Lesser General Public License
18		* along with libheif. If not, see <http://www.gnu.org/licenses/>.
19		*/
20
21		#include "common_utils.h"
22		#include <cassert>
23
24
25		uint8_t chroma_h_subsampling(heif_chroma c)
26	2.96k	{
27	2.96k	switch (c) {
28	0	case heif_chroma_monochrome:
29	2.24k	case heif_chroma_444:
30	2.24k	return 1;
31
32	662	case heif_chroma_420:
33	712	case heif_chroma_422:
34	712	return 2;
35
36	0	case heif_chroma_interleaved_RGB:
37	0	case heif_chroma_interleaved_RGBA:
38	0	default:
39	0	assert(false);
40	0	return 0;
41	2.96k	}
42	2.96k	}
43
44
45		uint8_t chroma_v_subsampling(heif_chroma c)
46	2.96k	{
47	2.96k	switch (c) {
48	0	case heif_chroma_monochrome:
49	2.24k	case heif_chroma_444:
50	2.29k	case heif_chroma_422:
51	2.29k	return 1;
52
53	662	case heif_chroma_420:
54	662	return 2;
55
56	0	case heif_chroma_interleaved_RGB:
57	0	case heif_chroma_interleaved_RGBA:
58	0	default:
59	0	assert(false);
60	0	return 0;
61	2.96k	}
62	2.96k	}
63
64
65		uint32_t get_subsampled_size_h(uint32_t width,
66		heif_channel channel,
67		heif_chroma chroma,
68		scaling_mode mode)
69	2.11k	{
70	2.11k	if (channel == heif_channel_Cb \|\|
71	1.92k	channel == heif_channel_Cr) {
72	368	uint8_t chromaSubH = chroma_h_subsampling(chroma);
73
74	368	switch (mode) {
75	16	case scaling_mode::round_up:
76		// NOLINTNEXTLINE(clang-analyzer-core.DivideZero)
77	16	return (width + chromaSubH - 1) / chromaSubH;
78	176	case scaling_mode::round_down:
79		// NOLINTNEXTLINE(clang-analyzer-core.DivideZero)
80	176	return width / chromaSubH;
81	176	case scaling_mode::is_divisible:
82	176	assert(width % chromaSubH == 0);
83	176	return width / chromaSubH;
84	0	default:
85	0	assert(false);
86	0	return 0;
87	368	}
88	1.75k	} else {
89	1.75k	return width;
90	1.75k	}
91	2.11k	}
92
93
94		uint32_t get_subsampled_size_v(uint32_t height,
95		heif_channel channel,
96		heif_chroma chroma,
97		scaling_mode mode)
98	2.11k	{
99	2.11k	if (channel == heif_channel_Cb \|\|
100	1.92k	channel == heif_channel_Cr) {
101	368	uint8_t chromaSubV = chroma_v_subsampling(chroma);
102
103	368	switch (mode) {
104	16	case scaling_mode::round_up:
105		// NOLINTNEXTLINE(clang-analyzer-core.DivideZero)
106	16	return (height + chromaSubV - 1) / chromaSubV;
107	176	case scaling_mode::round_down:
108		// NOLINTNEXTLINE(clang-analyzer-core.DivideZero)
109	176	return height / chromaSubV;
110	176	case scaling_mode::is_divisible:
111	176	assert(height % chromaSubV == 0);
112	176	return height / chromaSubV;
113	0	default:
114	0	assert(false);
115	0	return 0;
116	368	}
117	1.75k	} else {
118	1.75k	return height;
119	1.75k	}
120	2.11k	}
121
122
123		void get_subsampled_size(uint32_t width, uint32_t height,
124		heif_channel channel,
125		heif_chroma chroma,
126		uint32_t* subsampled_width, uint32_t* subsampled_height)
127	16	{
128	16	*subsampled_width = get_subsampled_size_h(width, channel, chroma, scaling_mode::round_up);
129	16	*subsampled_height = get_subsampled_size_v(height, channel, chroma, scaling_mode::round_up);
130	16	}
131
132
133
134		uint8_t compute_avif_profile(int bits_per_pixel, heif_chroma chroma)
135	0	{
136	0	if (bits_per_pixel <= 10 &&
137	0	(chroma == heif_chroma_420 \|\|
138	0	chroma == heif_chroma_monochrome)) {
139	0	return 0;
140	0	}
141	0	else if (bits_per_pixel <= 10 &&
142	0	chroma == heif_chroma_444) {
143	0	return 1;
144	0	}
145	0	else {
146	0	return 2;
147	0	}
148	0	}
149
150
151		std::string fourcc_to_string(uint32_t code)
152	903k	{
153	903k	std::string str(" ");
154	903k	str[0] = static_cast<char>((code >> 24) & 0xFF);
155	903k	str[1] = static_cast<char>((code >> 16) & 0xFF);
156	903k	str[2] = static_cast<char>((code >> 8) & 0xFF);
157	903k	str[3] = static_cast<char>((code >> 0) & 0xFF);
158
159	903k	return str;
160	903k	}
161
162
163		Result<std::string> vector_to_string(const std::vector<uint8_t>& vec)
164	0	{
165	0	if (vec.empty()) {
166	0	return std::string{}; // return empty string
167	0	}
168
169	0	if (vec.back() != 0) {
170	0	return Error{heif_error_Invalid_input,
171	0	heif_suberror_Unspecified,
172	0	"utf8string not null-terminated"};
173	0	}
174
175	0	for (size_t i=0;i<vec.size()-1;i++) {
176	0	if (vec[i] == 0) {
177	0	return Error{heif_error_Invalid_input,
178	0	heif_suberror_Unspecified,
179	0	"utf8string with null character"};
180	0	}
181	0	}
182
183	0	return std::string(vec.begin(), vec.end()-1);
184	0	}

Coverage Report

Created: 2025-12-31 07:53