1// Copyright 2014 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef CHROME_UTILITY_MEDIA_GALLERIES_IMAGE_METADATA_EXTRACTOR_H_
6#define CHROME_UTILITY_MEDIA_GALLERIES_IMAGE_METADATA_EXTRACTOR_H_
7
8#include <string>
9
10#include "base/basictypes.h"
11#include "base/callback_forward.h"
12#include "base/memory/ref_counted.h"
13
14namespace media {
15class DataSource;
16}
17
18namespace net {
19class DrainableIOBuffer;
20}
21
22namespace metadata {
23
24// Extracts a basic set of image metadata tags. Users must initialize the
25// library before use. Each class instance is 'one-time-use', and cannot be used
26// to extract metadata from multiple images.
27class ImageMetadataExtractor {
28 public:
29  typedef base::Callback<void(bool)> DoneCallback;
30
31  // One of these two is required before use of this class.
32  static bool InitializeLibrary();
33  static bool InitializeLibraryForTesting();
34
35  ImageMetadataExtractor();
36  ~ImageMetadataExtractor();
37
38  // |callback| called with whether or not the extraction succeeded. Should
39  // only be called once.
40  void Extract(media::DataSource* source, const DoneCallback& callback);
41
42  // All below methods require Extract to have already succeeded.
43  // Returns -1 if file does not define a width or height.
44  int width() const;
45  int height() const;
46
47  // In degrees.
48  int rotation() const;
49
50  // In pixels per inch.
51  double x_resolution() const;
52  double y_resolution() const;
53
54  // In the same string form as the original file.
55  const std::string& date() const;
56
57  const std::string& camera_make() const;
58  const std::string& camera_model() const;
59  double exposure_time_sec() const;
60  bool flash_fired() const;
61  double f_number() const;
62  double focal_length_mm() const;
63  int iso_equivalent() const;
64
65 private:
66  // Second half of the Extract method.
67  void FinishExtraction(const DoneCallback& callback,
68                        const scoped_refptr<net::DrainableIOBuffer>& buffer);
69
70  bool extracted_;
71
72  int width_;
73  int height_;
74
75  int rotation_;
76
77  double x_resolution_;
78  double y_resolution_;
79
80  std::string date_;
81
82  std::string camera_make_;
83  std::string camera_model_;
84  double exposure_time_sec_;
85  bool flash_fired_;
86  double f_number_;
87  double focal_length_mm_;
88  int iso_equivalent_;
89
90  DISALLOW_COPY_AND_ASSIGN(ImageMetadataExtractor);
91};
92
93}  // namespace metadata
94
95#endif  // CHROME_UTILITY_MEDIA_GALLERIES_IMAGE_METADATA_EXTRACTOR_H_
96