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1 /*
2  * Copyright (c) 2010, 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 "config.h"
32 #include "JPEGImageEncoder.h"
33 
34 #include "ImageData.h"
35 #include "IntSize.h"
36 #include "SkBitmap.h"
37 #include "SkColorPriv.h"
38 #include "SkUnPreMultiply.h"
39 extern "C" {
40 #include <stdio.h> // jpeglib.h needs stdio.h FILE
41 #include "jpeglib.h"
42 #include <setjmp.h>
43 }
44 
45 namespace WebCore {
46 
47 struct JPEGOutputBuffer : public jpeg_destination_mgr {
48     Vector<unsigned char>* output;
49     Vector<unsigned char> buffer;
50 };
51 
prepareOutput(j_compress_ptr cinfo)52 static void prepareOutput(j_compress_ptr cinfo)
53 {
54     JPEGOutputBuffer* out = static_cast<JPEGOutputBuffer*>(cinfo->dest);
55     const size_t internalBufferSize = 8192;
56     out->buffer.resize(internalBufferSize);
57     out->next_output_byte = out->buffer.data();
58     out->free_in_buffer = out->buffer.size();
59 }
60 
writeOutput(j_compress_ptr cinfo)61 static boolean writeOutput(j_compress_ptr cinfo)
62 {
63     JPEGOutputBuffer* out = static_cast<JPEGOutputBuffer*>(cinfo->dest);
64     out->output->append(out->buffer.data(), out->buffer.size());
65     out->next_output_byte = out->buffer.data();
66     out->free_in_buffer = out->buffer.size();
67     return TRUE;
68 }
69 
finishOutput(j_compress_ptr cinfo)70 static void finishOutput(j_compress_ptr cinfo)
71 {
72     JPEGOutputBuffer* out = static_cast<JPEGOutputBuffer*>(cinfo->dest);
73     const size_t size = out->buffer.size() - out->free_in_buffer;
74     out->output->append(out->buffer.data(), size);
75 }
76 
handleError(j_common_ptr common)77 static void handleError(j_common_ptr common)
78 {
79     jmp_buf* jumpBufferPtr = static_cast<jmp_buf*>(common->client_data);
80     longjmp(*jumpBufferPtr, -1);
81 }
82 
preMultipliedBGRAtoRGB(const void * pixels,unsigned int pixelCount,unsigned char * output)83 static void preMultipliedBGRAtoRGB(const void* pixels, unsigned int pixelCount, unsigned char* output)
84 {
85     const SkPMColor* input = static_cast<const SkPMColor*>(pixels);
86     for (; pixelCount-- > 0; ++input) {
87         *output++ = SkGetPackedR32(*input);
88         *output++ = SkGetPackedG32(*input);
89         *output++ = SkGetPackedB32(*input);
90     }
91 }
92 
RGBAtoRGB(const unsigned char * input,unsigned int pixels,unsigned char * output)93 static void RGBAtoRGB(const unsigned char* input, unsigned int pixels, unsigned char* output)
94 {
95     for (; pixels-- > 0; input += 4) {
96         *output++ = input[0];
97         *output++ = input[1];
98         *output++ = input[2];
99     }
100 }
101 
encodePixels(const IntSize & inputSize,unsigned char * inputPixels,bool premultiplied,int quality,Vector<unsigned char> * output)102 static bool encodePixels(const IntSize& inputSize, unsigned char* inputPixels,
103                          bool premultiplied, int quality, Vector<unsigned char>* output)
104 {
105     IntSize imageSize(inputSize);
106     imageSize.clampNegativeToZero();
107     JPEGOutputBuffer destination;
108     destination.output = output;
109     Vector<JSAMPLE> row;
110 
111     jpeg_compress_struct cinfo;
112     jpeg_error_mgr error;
113     cinfo.err = jpeg_std_error(&error);
114     error.error_exit = handleError;
115     jmp_buf jumpBuffer;
116     cinfo.client_data = &jumpBuffer;
117 
118     if (setjmp(jumpBuffer)) {
119         jpeg_destroy_compress(&cinfo);
120         return false;
121     }
122 
123     jpeg_create_compress(&cinfo);
124     cinfo.dest = &destination;
125     cinfo.dest->init_destination = prepareOutput;
126     cinfo.dest->empty_output_buffer = writeOutput;
127     cinfo.dest->term_destination = finishOutput;
128     cinfo.image_height = imageSize.height();
129     cinfo.image_width = imageSize.width();
130     cinfo.in_color_space = JCS_RGB;
131     cinfo.input_components = 3;
132 
133     jpeg_set_defaults(&cinfo);
134     jpeg_set_quality(&cinfo, quality, TRUE);
135     jpeg_start_compress(&cinfo, TRUE);
136 
137     unsigned char* pixels = inputPixels;
138     row.resize(cinfo.image_width * cinfo.input_components);
139     while (cinfo.next_scanline < cinfo.image_height) {
140         if (premultiplied)
141             preMultipliedBGRAtoRGB(pixels, cinfo.image_width, row.data());
142         else
143             RGBAtoRGB(pixels, cinfo.image_width, row.data());
144         jpeg_write_scanlines(&cinfo, row.dataSlot(), 1);
145         pixels += cinfo.image_width * 4;
146     }
147 
148     jpeg_finish_compress(&cinfo);
149     jpeg_destroy_compress(&cinfo);
150     return true;
151 }
152 
encode(const SkBitmap & bitmap,int quality,Vector<unsigned char> * output)153 bool JPEGImageEncoder::encode(const SkBitmap& bitmap, int quality, Vector<unsigned char>* output)
154 {
155     if (bitmap.config() != SkBitmap::kARGB_8888_Config)
156         return false; // Only support ARGB 32 bpp skia bitmaps.
157 
158     SkAutoLockPixels bitmapLock(bitmap);
159     IntSize imageSize(bitmap.width(), bitmap.height());
160 
161     return encodePixels(imageSize, static_cast<unsigned char *>(bitmap.getPixels()),
162                         true, quality, output);
163 }
164 
encode(const ImageData & imageData,int quality,Vector<unsigned char> * output)165 bool JPEGImageEncoder::encode(const ImageData& imageData, int quality, Vector<unsigned char>* output)
166 {
167     return encodePixels(imageData.size(), imageData.data()->data()->data(),
168                         false, quality, output);
169 }
170 
171 } // namespace WebCore
172