1 /*
2 * Copyright (c) 2008, 2009, Google Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met:
7 *
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following disclaimer
12 * in the documentation and/or other materials provided with the
13 * distribution.
14 * * Neither the name of Google Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31 #include "third_party/blink/renderer/platform/image-decoders/bmp/bmp_image_decoder.h"
32
33 #include "third_party/blink/renderer/platform/image-decoders/bmp/bmp_image_reader.h"
34 #include "third_party/blink/renderer/platform/image-decoders/fast_shared_buffer_reader.h"
35
36 namespace blink {
37
38 // Number of bits in .BMP used to store the file header (doesn't match
39 // "sizeof(BMPImageDecoder::BitmapFileHeader)" since we omit some fields and
40 // don't pack).
41 static const size_t kSizeOfFileHeader = 14;
42
BMPImageDecoder(AlphaOption alpha_option,const ColorBehavior & color_behavior,size_t max_decoded_bytes)43 BMPImageDecoder::BMPImageDecoder(AlphaOption alpha_option,
44 const ColorBehavior& color_behavior,
45 size_t max_decoded_bytes)
46 : ImageDecoder(alpha_option,
47 ImageDecoder::kDefaultBitDepth,
48 color_behavior,
49 max_decoded_bytes),
50 decoded_offset_(0) {}
51
52 BMPImageDecoder::~BMPImageDecoder() = default;
53
OnSetData(SegmentReader * data)54 void BMPImageDecoder::OnSetData(SegmentReader* data) {
55 if (reader_)
56 reader_->SetData(data);
57 }
58
SetFailed()59 bool BMPImageDecoder::SetFailed() {
60 reader_.reset();
61 return ImageDecoder::SetFailed();
62 }
63
Decode(bool only_size)64 void BMPImageDecoder::Decode(bool only_size) {
65 if (Failed())
66 return;
67
68 // If we couldn't decode the image but we've received all the data, decoding
69 // has failed.
70 if (!DecodeHelper(only_size) && IsAllDataReceived())
71 SetFailed();
72 // If we're done decoding the image, we don't need the BMPImageReader
73 // anymore. (If we failed, |reader_| has already been cleared.)
74 else if (!frame_buffer_cache_.IsEmpty() &&
75 (frame_buffer_cache_.front().GetStatus() ==
76 ImageFrame::kFrameComplete))
77 reader_.reset();
78 }
79
DecodeHelper(bool only_size)80 bool BMPImageDecoder::DecodeHelper(bool only_size) {
81 size_t img_data_offset = 0;
82 if ((decoded_offset_ < kSizeOfFileHeader) &&
83 !ProcessFileHeader(img_data_offset))
84 return false;
85
86 if (!reader_) {
87 reader_ = std::make_unique<BMPImageReader>(this, decoded_offset_,
88 img_data_offset, false);
89 reader_->SetData(data_.get());
90 }
91
92 if (!frame_buffer_cache_.IsEmpty())
93 reader_->SetBuffer(&frame_buffer_cache_.front());
94
95 return reader_->DecodeBMP(only_size);
96 }
97
ProcessFileHeader(size_t & img_data_offset)98 bool BMPImageDecoder::ProcessFileHeader(size_t& img_data_offset) {
99 // Read file header.
100 DCHECK(!decoded_offset_);
101 FastSharedBufferReader fast_reader(data_);
102 char buffer[kSizeOfFileHeader];
103 const char* file_header;
104 uint16_t file_type;
105 if (!GetFileType(fast_reader, buffer, file_header, file_type))
106 return false;
107
108 // See if this is a bitmap filetype we understand.
109 enum {
110 BMAP = 0x424D, // "BM"
111 BITMAPARRAY = 0x4241, // "BA"
112 // The following additional OS/2 2.x header values (see
113 // http://www.fileformat.info/format/os2bmp/egff.htm ) aren't widely
114 // decoded, and are unlikely to be in much use.
115 /*
116 ICON = 0x4943, // "IC"
117 POINTER = 0x5054, // "PT"
118 COLORICON = 0x4349, // "CI"
119 COLORPOINTER = 0x4350, // "CP"
120 */
121 };
122 if (file_type == BITMAPARRAY) {
123 // Skip initial 14-byte header, try to read the first entry as a BMAP.
124 decoded_offset_ += kSizeOfFileHeader;
125 if (!GetFileType(fast_reader, buffer, file_header, file_type))
126 return false;
127 }
128 if (file_type != BMAP)
129 return SetFailed();
130
131 img_data_offset = BMPImageReader::ReadUint32(&file_header[10]);
132 decoded_offset_ += kSizeOfFileHeader;
133 return true;
134 }
135
GetFileType(const FastSharedBufferReader & fast_reader,char * buffer,const char * & file_header,uint16_t & file_type) const136 bool BMPImageDecoder::GetFileType(const FastSharedBufferReader& fast_reader,
137 char* buffer,
138 const char*& file_header,
139 uint16_t& file_type) const {
140 if (data_->size() - decoded_offset_ < kSizeOfFileHeader)
141 return false;
142 file_header = fast_reader.GetConsecutiveData(decoded_offset_,
143 kSizeOfFileHeader, buffer);
144 file_type = (file_header[0] << 8) | static_cast<uint8_t>(file_header[1]);
145 return true;
146 }
147
148 } // namespace blink
149