1 /*
2  * Copyright (C) 2015 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 /**
18  * @addtogroup Camera
19  * @{
20  */
21 
22 /**
23  * @file NdkCameraMetadata.h
24  */
25 
26 /*
27  * This file defines an NDK API.
28  * Do not remove methods.
29  * Do not change method signatures.
30  * Do not change the value of constants.
31  * Do not change the size of any of the classes defined in here.
32  * Do not reference types that are not part of the NDK.
33  * Do not #include files that aren't part of the NDK.
34  */
35 
36 #ifndef _NDK_CAMERA_METADATA_H
37 #define _NDK_CAMERA_METADATA_H
38 
39 #include <sys/cdefs.h>
40 
41 #include "NdkCameraError.h"
42 #include "NdkCameraMetadataTags.h"
43 
44 __BEGIN_DECLS
45 
46 #if __ANDROID_API__ >= 24
47 
48 /**
49  * ACameraMetadata is opaque type that provides access to read-only camera metadata like camera
50  * characteristics (via {@link ACameraManager_getCameraCharacteristics}) or capture results (via
51  * {@link ACameraCaptureSession_captureCallback_result}).
52  */
53 typedef struct ACameraMetadata ACameraMetadata;
54 
55 /**
56  * Possible data types of a metadata entry.
57  *
58  * Keep in sync with system/media/include/system/camera_metadata.h
59  */
60 enum {
61     /// Unsigned 8-bit integer (uint8_t)
62     ACAMERA_TYPE_BYTE = 0,
63     /// Signed 32-bit integer (int32_t)
64     ACAMERA_TYPE_INT32 = 1,
65     /// 32-bit float (float)
66     ACAMERA_TYPE_FLOAT = 2,
67     /// Signed 64-bit integer (int64_t)
68     ACAMERA_TYPE_INT64 = 3,
69     /// 64-bit float (double)
70     ACAMERA_TYPE_DOUBLE = 4,
71     /// A 64-bit fraction (ACameraMetadata_rational)
72     ACAMERA_TYPE_RATIONAL = 5,
73     /// Number of type fields
74     ACAMERA_NUM_TYPES
75 };
76 
77 /**
78  * Definition of rational data type in {@link ACameraMetadata}.
79  */
80 typedef struct ACameraMetadata_rational {
81     int32_t numerator;
82     int32_t denominator;
83 } ACameraMetadata_rational;
84 
85 /**
86  * A single camera metadata entry.
87  *
88  * <p>Each entry is an array of values, though many metadata fields may only have 1 entry in the
89  * array.</p>
90  */
91 typedef struct ACameraMetadata_entry {
92     /**
93      * The tag identifying the entry.
94      *
95      * <p> It is one of the values defined in {@link NdkCameraMetadataTags.h}, and defines how the
96      * entry should be interpreted and which parts of the API provide it.
97      * See {@link NdkCameraMetadataTags.h} for more details. </p>
98      */
99     uint32_t tag;
100 
101     /**
102      * The data type of this metadata entry.
103      *
104      * <p>Must be one of ACAMERA_TYPE_* enum values defined above. A particular tag always has the
105      * same type.</p>
106      */
107     uint8_t  type;
108 
109     /**
110      * Count of elements (NOT count of bytes) in this metadata entry.
111      */
112     uint32_t count;
113 
114     /**
115      * Pointer to the data held in this metadata entry.
116      *
117      * <p>The type field above defines which union member pointer is valid. The count field above
118      * defines the length of the data in number of elements.</p>
119      */
120     union {
121         uint8_t *u8;
122         int32_t *i32;
123         float   *f;
124         int64_t *i64;
125         double  *d;
126         ACameraMetadata_rational* r;
127     } data;
128 } ACameraMetadata_entry;
129 
130 /**
131  * A single read-only camera metadata entry.
132  *
133  * <p>Each entry is an array of values, though many metadata fields may only have 1 entry in the
134  * array.</p>
135  */
136 typedef struct ACameraMetadata_const_entry {
137     /**
138      * The tag identifying the entry.
139      *
140      * <p> It is one of the values defined in {@link NdkCameraMetadataTags.h}, and defines how the
141      * entry should be interpreted and which parts of the API provide it.
142      * See {@link NdkCameraMetadataTags.h} for more details. </p>
143      */
144     uint32_t tag;
145 
146     /**
147      * The data type of this metadata entry.
148      *
149      * <p>Must be one of ACAMERA_TYPE_* enum values defined above. A particular tag always has the
150      * same type.</p>
151      */
152     uint8_t  type;
153 
154     /**
155      * Count of elements (NOT count of bytes) in this metadata entry.
156      */
157     uint32_t count;
158 
159     /**
160      * Pointer to the data held in this metadata entry.
161      *
162      * <p>The type field above defines which union member pointer is valid. The count field above
163      * defines the length of the data in number of elements.</p>
164      */
165     union {
166         const uint8_t *u8;
167         const int32_t *i32;
168         const float   *f;
169         const int64_t *i64;
170         const double  *d;
171         const ACameraMetadata_rational* r;
172     } data;
173 } ACameraMetadata_const_entry;
174 
175 /**
176  * Get a metadata entry from an input {@link ACameraMetadata}.
177  *
178  * <p>The memory of the data field in the returned entry is managed by camera framework. Do not
179  * attempt to free it.</p>
180  *
181  * @param metadata the {@link ACameraMetadata} of interest.
182  * @param tag the tag value of the camera metadata entry to be get.
183  * @param entry the output {@link ACameraMetadata_const_entry} will be filled here if the method
184  *        call succeeeds.
185  *
186  * @return <ul>
187  *         <li>{@link ACAMERA_OK} if the method call succeeds.</li>
188  *         <li>{@link ACAMERA_ERROR_INVALID_PARAMETER} if metadata or entry is NULL.</li>
189  *         <li>{@link ACAMERA_ERROR_METADATA_NOT_FOUND} if input metadata does not contain an entry
190  *             of input tag value.</li></ul>
191  */
192 camera_status_t ACameraMetadata_getConstEntry(
193         const ACameraMetadata* metadata, uint32_t tag, /*out*/ACameraMetadata_const_entry* entry);
194 
195 /**
196  * List all the entry tags in input {@link ACameraMetadata}.
197  *
198  * @param metadata the {@link ACameraMetadata} of interest.
199  * @param numEntries number of metadata entries in input {@link ACameraMetadata}
200  * @param tags the tag values of the metadata entries. Length of tags is returned in numEntries
201  *             argument. The memory is managed by ACameraMetadata itself and must NOT be free/delete
202  *             by application. Do NOT access tags after calling ACameraMetadata_free.
203  *
204  * @return <ul>
205  *         <li>{@link ACAMERA_OK} if the method call succeeds.</li>
206  *         <li>{@link ACAMERA_ERROR_INVALID_PARAMETER} if metadata, numEntries or tags is NULL.</li>
207  *         <li>{@link ACAMERA_ERROR_UNKNOWN} if the method fails for some other reasons.</li></ul>
208  */
209 camera_status_t ACameraMetadata_getAllTags(
210         const ACameraMetadata* metadata, /*out*/int32_t* numEntries, /*out*/const uint32_t** tags);
211 
212 /**
213  * Create a copy of input {@link ACameraMetadata}.
214  *
215  * <p>The returned ACameraMetadata must be freed by the application by {@link ACameraMetadata_free}
216  * after application is done using it.</p>
217  *
218  * @param src the input {@link ACameraMetadata} to be copied.
219  *
220  * @return a valid ACameraMetadata pointer or NULL if the input metadata cannot be copied.
221  */
222 ACameraMetadata* ACameraMetadata_copy(const ACameraMetadata* src);
223 
224 /**
225  * Free a {@link ACameraMetadata} structure.
226  *
227  * @param metadata the {@link ACameraMetadata} to be freed.
228  */
229 void ACameraMetadata_free(ACameraMetadata* metadata);
230 
231 #endif /* __ANDROID_API__ >= 24 */
232 
233 __END_DECLS
234 
235 #endif /* _NDK_CAMERA_METADATA_H */
236 
237 /** @} */
238