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