SkJpegUtility.h revision e3b95ce468c73af8247ba9582a7b84548b19f06a 
1/*
2 * Copyright 2015 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8
9#ifndef SkJpegUtility_codec_DEFINED
10#define SkJpegUtility_codec_DEFINED
11
12#include "SkStream.h"
13
14#include <setjmp.h>
15// stdio is needed for jpeglib
16#include <stdio.h>
17
18extern "C" {
19    #include "jpeglib.h"
20    #include "jerror.h"
21}
22
23static constexpr uint32_t kICCMarker = JPEG_APP0 + 2;
24static constexpr uint32_t kICCMarkerHeaderSize = 14;
25static constexpr uint8_t kICCSig[] = {
26        'I', 'C', 'C', '_', 'P', 'R', 'O', 'F', 'I', 'L', 'E', '\0',
27};
28
29/*
30 * Error handling struct
31 */
32struct skjpeg_error_mgr : jpeg_error_mgr {
33    jmp_buf fJmpBuf;
34};
35
36/*
37 * Error handling function
38 */
39void skjpeg_err_exit(j_common_ptr cinfo);
40
41/*
42 * Source handling struct for that allows libjpeg to use our stream object
43 */
44struct skjpeg_source_mgr : jpeg_source_mgr {
45    skjpeg_source_mgr(SkStream* stream);
46
47    SkStream* fStream; // unowned
48    enum {
49        // TODO (msarett): Experiment with different buffer sizes.
50        // This size was chosen because it matches SkImageDecoder.
51        kBufferSize = 1024
52    };
53    uint8_t fBuffer[kBufferSize];
54};
55
56#endif
57