1 /*
2 * Copyright (C) 2021 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16
17 #include "wbmp_format_agent.h"
18
19 #include "image_log.h"
20 #include "image_plugin_type.h"
21 #include "plugin_service.h"
22 #include "string"
23
24 #undef LOG_DOMAIN
25 #define LOG_DOMAIN LOG_TAG_DOMAIN_ID_PLUGIN
26
27 #undef LOG_TAG
28 #define LOG_TAG "WbmpFormatAgent"
29
30 namespace OHOS {
31 namespace ImagePlugin {
32 using namespace ImagePlugin;
33 using namespace MultimediaPlugin;
34
35 const std::string FORMAT_TYPE = "image/vnd.wap.wbmp";
36 constexpr uint32_t HEADER_SIZE = 32;
37 constexpr uint8_t SHIF_BIT_MASK = 7;
38 constexpr uint8_t LOW_BIT_MASK = 0x7F;
39 constexpr uint8_t HIGH_BIT_MASK = 0x80;
40
read_byte(uint8_t * stream,uint8_t & value,uint32_t & offset,uint32_t dataSize)41 bool WbmpFormatAgent::read_byte(uint8_t *stream, uint8_t &value, uint32_t &offset, uint32_t dataSize)
42 {
43 if (stream == nullptr) {
44 IMAGE_LOGE("read_byte: stream is nullptr");
45 return false;
46 }
47 if (offset >= dataSize) {
48 IMAGE_LOGE("read_header data offset %{public}u. dataSize %{public}u", offset, dataSize);
49 return false;
50 }
51 value = *(stream + offset);
52 offset++;
53 return true;
54 }
55
read_mbf(uint8_t * stream,uint64_t & value,uint32_t & offset,uint32_t dataSize)56 bool WbmpFormatAgent::read_mbf(uint8_t *stream, uint64_t &value, uint32_t &offset, uint32_t dataSize)
57 {
58 uint64_t n = 0;
59 uint8_t data;
60 const uint64_t kLimit = 0xFE00000000000000;
61 do {
62 if (n & kLimit) { // Will overflow on shift by 7.
63 return false;
64 }
65 if (!read_byte(stream, data, offset, dataSize)) {
66 return false;
67 }
68 n = (n << SHIF_BIT_MASK) | (data & LOW_BIT_MASK);
69 } while (data & HIGH_BIT_MASK);
70 value = n;
71 return true;
72 }
73
read_header(const void * stream,uint32_t dataSize)74 bool WbmpFormatAgent::read_header(const void *stream, uint32_t dataSize)
75 {
76 uint8_t data;
77 uint8_t *pData = static_cast<uint8_t *>(const_cast<void *>(stream));
78 uint32_t offset = 0;
79
80 if (!read_byte(pData, data, offset, dataSize) || data != 0) { // unknown type
81 return false;
82 }
83 IMAGE_LOGD("read_header data %{public}d.", data);
84
85 if (!read_byte(pData, data, offset, dataSize) || (data & 0x9F)) { // skip fixed header
86 return false;
87 }
88 IMAGE_LOGD("read_header data %{public}d.", data);
89
90 uint64_t width;
91 uint64_t height;
92 if (!read_mbf(pData, width, offset, dataSize) || width > 0xFFFF || !width) {
93 return false;
94 }
95 IMAGE_LOGD("read_header width %{public}lld.", static_cast<long long>(width));
96
97 if (!read_mbf(pData, height, offset, dataSize) || height > 0xFFFF || !height) {
98 return false;
99 }
100 IMAGE_LOGD("read_header height %{public}lld.", static_cast<long long>(height));
101
102 return true;
103 }
104
105
GetFormatType()106 std::string WbmpFormatAgent::GetFormatType()
107 {
108 return FORMAT_TYPE;
109 }
110
GetHeaderSize()111 uint32_t WbmpFormatAgent::GetHeaderSize()
112 {
113 return HEADER_SIZE;
114 }
115
CheckFormat(const void * headerData,uint32_t dataSize)116 bool WbmpFormatAgent::CheckFormat(const void *headerData, uint32_t dataSize)
117 {
118 if (headerData == nullptr) {
119 IMAGE_LOGE("check format failed: header data is null.");
120 return false;
121 }
122
123 if (!read_header(headerData, dataSize)) {
124 IMAGE_LOGD("not wbmp image format.");
125 return false;
126 }
127
128 IMAGE_LOGD("wbmp image format ok.");
129 return true;
130 }
131 } // namespace ImagePlugin
132 } // namespace OHOS
133