MetaData.h revision ee7ff20e69498ebd53dd9717a0f984188341a75e 
1/*
2 * Copyright (C) 2009 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 META_DATA_H_
18
19#define META_DATA_H_
20
21#include <sys/types.h>
22
23#include <stdint.h>
24
25#include <utils/RefBase.h>
26#include <utils/KeyedVector.h>
27
28namespace android {
29
30// The following keys map to int32_t data unless indicated otherwise.
31enum {
32    kKeyMIMEType          = 'mime',  // cstring
33    kKeyWidth             = 'widt',
34    kKeyHeight            = 'heig',
35    kKeyChannelCount      = '#chn',
36    kKeySampleRate        = 'srte',
37    kKeyBitRate           = 'brte',  // int32_t (bps)
38    kKeyESDS              = 'esds',  // raw data
39    kKeyAVCC              = 'avcc',  // raw data
40    kKeyVorbisInfo        = 'vinf',  // raw data
41    kKeyVorbisBooks       = 'vboo',  // raw data
42    kKeyWantsNALFragments = 'NALf',
43    kKeyIsSyncFrame       = 'sync',  // int32_t (bool)
44    kKeyIsCodecConfig     = 'conf',  // int32_t (bool)
45    kKeyTime              = 'time',  // int64_t (usecs)
46    kKeyDuration          = 'dura',  // int64_t (usecs)
47    kKeyColorFormat       = 'colf',
48    kKeyPlatformPrivate   = 'priv',  // pointer
49    kKeyDecoderComponent  = 'decC',  // cstring
50    kKeyBufferID          = 'bfID',
51    kKeyMaxInputSize      = 'inpS',
52    kKeyThumbnailTime     = 'thbT',  // int64_t (usecs)
53
54    kKeyAlbum             = 'albu',  // cstring
55    kKeyArtist            = 'arti',  // cstring
56    kKeyAlbumArtist       = 'aart',  // cstring
57    kKeyComposer          = 'comp',  // cstring
58    kKeyGenre             = 'genr',  // cstring
59    kKeyTitle             = 'titl',  // cstring
60    kKeyYear              = 'year',  // cstring
61    kKeyAlbumArt          = 'albA',  // compressed image data
62    kKeyAlbumArtMIME      = 'alAM',  // cstring
63    kKeyAuthor            = 'auth',  // cstring
64    kKeyCDTrackNumber     = 'cdtr',  // cstring
65    kKeyDiscNumber        = 'dnum',  // cstring
66    kKeyDate              = 'date',  // cstring
67    kKeyWriter            = 'writ',  // cstring
68};
69
70enum {
71    kTypeESDS        = 'esds',
72    kTypeAVCC        = 'avcc',
73};
74
75class MetaData : public RefBase {
76public:
77    MetaData();
78    MetaData(const MetaData &from);
79
80    enum Type {
81        TYPE_NONE     = 'none',
82        TYPE_C_STRING = 'cstr',
83        TYPE_INT32    = 'in32',
84        TYPE_INT64    = 'in64',
85        TYPE_FLOAT    = 'floa',
86        TYPE_POINTER  = 'ptr ',
87    };
88
89    void clear();
90    bool remove(uint32_t key);
91
92    bool setCString(uint32_t key, const char *value);
93    bool setInt32(uint32_t key, int32_t value);
94    bool setInt64(uint32_t key, int64_t value);
95    bool setFloat(uint32_t key, float value);
96    bool setPointer(uint32_t key, void *value);
97
98    bool findCString(uint32_t key, const char **value);
99    bool findInt32(uint32_t key, int32_t *value);
100    bool findInt64(uint32_t key, int64_t *value);
101    bool findFloat(uint32_t key, float *value);
102    bool findPointer(uint32_t key, void **value);
103
104    bool setData(uint32_t key, uint32_t type, const void *data, size_t size);
105
106    bool findData(uint32_t key, uint32_t *type,
107                  const void **data, size_t *size) const;
108
109protected:
110    virtual ~MetaData();
111
112private:
113    struct typed_data {
114        typed_data();
115        ~typed_data();
116
117        typed_data(const MetaData::typed_data &);
118        typed_data &operator=(const MetaData::typed_data &);
119
120        void clear();
121        void setData(uint32_t type, const void *data, size_t size);
122        void getData(uint32_t *type, const void **data, size_t *size) const;
123
124    private:
125        uint32_t mType;
126        size_t mSize;
127
128        union {
129            void *ext_data;
130            float reservoir;
131        } u;
132
133        bool usesReservoir() const {
134            return mSize <= sizeof(u.reservoir);
135        }
136
137        void allocateStorage(size_t size);
138        void freeStorage();
139
140        void *storage() {
141            return usesReservoir() ? &u.reservoir : u.ext_data;
142        }
143
144        const void *storage() const {
145            return usesReservoir() ? &u.reservoir : u.ext_data;
146        }
147    };
148
149    KeyedVector<uint32_t, typed_data> mItems;
150
151    // MetaData &operator=(const MetaData &);
152};
153
154}  // namespace android
155
156#endif  // META_DATA_H_
157