CameraMetadata.h revision fc42642ab78da5fe25bcbea7a568bf880268a9dc 
1/*
2 * Copyright (C) 2012 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef ANDROID_CLIENT_CAMERA2_CAMERAMETADATA_CPP
18#define ANDROID_CLIENT_CAMERA2_CAMERAMETADATA_CPP
19
20#include "system/camera_metadata.h"
21#include <utils/String8.h>
22#include <utils/Vector.h>
23
24namespace android {
25
26/**
27 * A convenience wrapper around the C-based camera_metadata_t library.
28 */
29class CameraMetadata {
30  public:
31    /** Creates an empty object; best used when expecting to acquire contents
32     * from elsewhere */
33    CameraMetadata();
34    /** Creates an object with space for entryCapacity entries, with
35     * dataCapacity extra storage */
36    CameraMetadata(size_t entryCapacity, size_t dataCapacity = 10);
37
38    ~CameraMetadata();
39
40    /** Takes ownership of passed-in buffer */
41    CameraMetadata(camera_metadata_t *buffer);
42    /** Clones the metadata */
43    CameraMetadata(const CameraMetadata &other);
44
45    /**
46     * Assignment clones metadata buffer.
47     */
48    CameraMetadata &operator=(const CameraMetadata &other);
49    CameraMetadata &operator=(const camera_metadata_t *buffer);
50
51    /**
52     * Release a raw metadata buffer to the caller. After this call,
53     * CameraMetadata no longer references the buffer, and the caller takes
54     * responsibility for freeing the raw metadata buffer (using
55     * free_camera_metadata()), or for handing it to another CameraMetadata
56     * instance.
57     */
58    camera_metadata_t* release();
59
60    /**
61     * Clear the metadata buffer and free all storage used by it
62     */
63    void clear();
64
65    /**
66     * Acquire a raw metadata buffer from the caller. After this call,
67     * the caller no longer owns the raw buffer, and must not free or manipulate it.
68     * If CameraMetadata already contains metadata, it is freed.
69     */
70    void acquire(camera_metadata_t* buffer);
71
72    /**
73     * Acquires raw buffer from other CameraMetadata object. After the call, the argument
74     * object no longer has any metadata.
75     */
76    void acquire(CameraMetadata &other);
77
78    /**
79     * Append metadata from another CameraMetadata object.
80     */
81    status_t append(const CameraMetadata &other);
82
83    /**
84     * Number of metadata entries.
85     */
86    size_t entryCount() const;
87
88    /**
89     * Is the buffer empty (no entires)
90     */
91    bool isEmpty() const;
92
93    /**
94     * Sort metadata buffer for faster find
95     */
96    status_t sort();
97
98    /**
99     * Update metadata entry. Will create entry if it doesn't exist already, and
100     * will reallocate the buffer if insufficient space exists. Overloaded for
101     * the various types of valid data.
102     */
103    status_t update(uint32_t tag,
104            const uint8_t *data, size_t data_count);
105    status_t update(uint32_t tag,
106            const int32_t *data, size_t data_count);
107    status_t update(uint32_t tag,
108            const float *data, size_t data_count);
109    status_t update(uint32_t tag,
110            const int64_t *data, size_t data_count);
111    status_t update(uint32_t tag,
112            const double *data, size_t data_count);
113    status_t update(uint32_t tag,
114            const camera_metadata_rational_t *data, size_t data_count);
115    status_t update(uint32_t tag,
116            const String8 &string);
117
118    template<typename T>
119    status_t update(uint32_t tag, Vector<T> data) {
120        return update(tag, data.array(), data.size());
121    }
122
123    /**
124     * Check if a metadata entry exists for a given tag id
125     *
126     */
127    bool exists(uint32_t tag) const;
128
129    /**
130     * Get metadata entry by tag id
131     */
132    camera_metadata_entry find(uint32_t tag);
133
134    /**
135     * Get metadata entry by tag id, with no editing
136     */
137    camera_metadata_ro_entry find(uint32_t tag) const;
138
139    /**
140     * Delete metadata entry by tag
141     */
142    status_t erase(uint32_t tag);
143
144    /**
145     * Dump contents into FD for debugging. The verbosity levels are
146     * 0: Tag entry information only, no data values
147     * 1: Level 0 plus at most 16 data values per entry
148     * 2: All information
149     *
150     * The indentation parameter sets the number of spaces to add to the start
151     * each line of output.
152     */
153    void dump(int fd, int verbosity = 1, int indentation = 0) const;
154
155  private:
156    camera_metadata_t *mBuffer;
157
158    /**
159     * Check if tag has a given type
160     */
161    status_t checkType(uint32_t tag, uint8_t expectedType);
162
163    /**
164     * Base update entry method
165     */
166    status_t update(uint32_t tag, const void *data, size_t data_count);
167
168    /**
169     * Resize metadata buffer if needed by reallocating it and copying it over.
170     */
171    status_t resizeIfNeeded(size_t extraEntries, size_t extraData);
172
173};
174
175}; // namespace android
176
177#endif
178