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Diffstat (limited to 'include/android/metadata/system/camera_metadata.h')
| -rw-r--r-- | include/android/metadata/system/camera_metadata.h | 580 |
1 files changed, 580 insertions, 0 deletions
diff --git a/include/android/metadata/system/camera_metadata.h b/include/android/metadata/system/camera_metadata.h new file mode 100644 index 00000000..46e7ac00 --- /dev/null +++ b/include/android/metadata/system/camera_metadata.h @@ -0,0 +1,580 @@ +/* + * Copyright (C) 2012 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#ifndef SYSTEM_MEDIA_INCLUDE_ANDROID_CAMERA_METADATA_H +#define SYSTEM_MEDIA_INCLUDE_ANDROID_CAMERA_METADATA_H + +#include <string.h> +#include <stdint.h> +#include <cutils/compiler.h> + +#ifdef __cplusplus +extern "C" { +#endif + +/** + * Tag hierarchy and enum definitions for camera_metadata_entry + * ============================================================================= + */ + +/** + * Main enum definitions are in a separate file to make it easy to + * maintain + */ +#include "camera_metadata_tags.h" + +/** + * Enum range for each top-level category + */ +ANDROID_API +extern unsigned int camera_metadata_section_bounds[ANDROID_SECTION_COUNT][2]; +ANDROID_API +extern const char *camera_metadata_section_names[ANDROID_SECTION_COUNT]; + +/** + * Type definitions for camera_metadata_entry + * ============================================================================= + */ +enum { + // Unsigned 8-bit integer (uint8_t) + TYPE_BYTE = 0, + // Signed 32-bit integer (int32_t) + TYPE_INT32 = 1, + // 32-bit float (float) + TYPE_FLOAT = 2, + // Signed 64-bit integer (int64_t) + TYPE_INT64 = 3, + // 64-bit float (double) + TYPE_DOUBLE = 4, + // A 64-bit fraction (camera_metadata_rational_t) + TYPE_RATIONAL = 5, + // Number of type fields + NUM_TYPES +}; + +typedef struct camera_metadata_rational { + int32_t numerator; + int32_t denominator; +} camera_metadata_rational_t; + +/** + * A reference to a metadata entry in a buffer. + * + * The data union pointers point to the real data in the buffer, and can be + * modified in-place if the count does not need to change. The count is the + * number of entries in data of the entry's type, not a count of bytes. + */ +typedef struct camera_metadata_entry { + size_t index; + uint32_t tag; + uint8_t type; + size_t count; + union { + uint8_t *u8; + int32_t *i32; + float *f; + int64_t *i64; + double *d; + camera_metadata_rational_t *r; + } data; +} camera_metadata_entry_t; + +/** + * A read-only reference to a metadata entry in a buffer. Identical to + * camera_metadata_entry in layout + */ +typedef struct camera_metadata_ro_entry { + size_t index; + uint32_t tag; + uint8_t type; + size_t count; + union { + const uint8_t *u8; + const int32_t *i32; + const float *f; + const int64_t *i64; + const double *d; + const camera_metadata_rational_t *r; + } data; +} camera_metadata_ro_entry_t; + +/** + * Size in bytes of each entry type + */ +ANDROID_API +extern const size_t camera_metadata_type_size[NUM_TYPES]; + +/** + * Human-readable name of each entry type + */ +ANDROID_API +extern const char* camera_metadata_type_names[NUM_TYPES]; + +/** + * Main definitions for the metadata entry and array structures + * ============================================================================= + */ + +/** + * A packet of metadata. This is a list of metadata entries, each of which has + * an integer tag to identify its meaning, 'type' and 'count' field, and the + * data, which contains a 'count' number of entries of type 'type'. The packet + * has a fixed capacity for entries and for extra data. A new entry uses up one + * entry slot, and possibly some amount of data capacity; the function + * calculate_camera_metadata_entry_data_size() provides the amount of data + * capacity that would be used up by an entry. + * + * Entries are not sorted by default, and are not forced to be unique - multiple + * entries with the same tag are allowed. The packet will not dynamically resize + * when full. + * + * The packet is contiguous in memory, with size in bytes given by + * get_camera_metadata_size(). Therefore, it can be copied safely with memcpy() + * to a buffer of sufficient size. The copy_camera_metadata() function is + * intended for eliminating unused capacity in the destination packet. + */ +struct camera_metadata; +typedef struct camera_metadata camera_metadata_t; + +/** + * Functions for manipulating camera metadata + * ============================================================================= + * + * NOTE: Unless otherwise specified, functions that return type "int" + * return 0 on success, and non-0 value on error. + */ + +/** + * Allocate a new camera_metadata structure, with some initial space for entries + * and extra data. The entry_capacity is measured in entry counts, and + * data_capacity in bytes. The resulting structure is all contiguous in memory, + * and can be freed with free_camera_metadata(). + */ +ANDROID_API +camera_metadata_t *allocate_camera_metadata(size_t entry_capacity, + size_t data_capacity); + +/** + * Get the required alignment of a packet of camera metadata, which is the + * maximal alignment of the embedded camera_metadata, camera_metadata_buffer_entry, + * and camera_metadata_data. + */ +ANDROID_API +size_t get_camera_metadata_alignment(); + +/** + * Allocate a new camera_metadata structure of size src_size. Copy the data, + * ignoring alignment, and then attempt validation. If validation + * fails, free the memory and return NULL. Otherwise return the pointer. + * + * The resulting pointer can be freed with free_camera_metadata(). + */ +ANDROID_API +camera_metadata_t *allocate_copy_camera_metadata_checked( + const camera_metadata_t *src, + size_t src_size); + +/** + * Place a camera metadata structure into an existing buffer. Returns NULL if + * the buffer is too small for the requested number of reserved entries and + * bytes of data. The entry_capacity is measured in entry counts, and + * data_capacity in bytes. If the buffer is larger than the required space, + * unused space will be left at the end. If successful, returns a pointer to the + * metadata header placed at the start of the buffer. It is the caller's + * responsibility to free the original buffer; do not call + * free_camera_metadata() with the returned pointer. + */ +ANDROID_API +camera_metadata_t *place_camera_metadata(void *dst, size_t dst_size, + size_t entry_capacity, + size_t data_capacity); + +/** + * Free a camera_metadata structure. Should only be used with structures + * allocated with allocate_camera_metadata(). + */ +ANDROID_API +void free_camera_metadata(camera_metadata_t *metadata); + +/** + * Calculate the buffer size needed for a metadata structure of entry_count + * metadata entries, needing a total of data_count bytes of extra data storage. + */ +ANDROID_API +size_t calculate_camera_metadata_size(size_t entry_count, + size_t data_count); + +/** + * Get current size of entire metadata structure in bytes, including reserved + * but unused space. + */ +ANDROID_API +size_t get_camera_metadata_size(const camera_metadata_t *metadata); + +/** + * Get size of entire metadata buffer in bytes, not including reserved but + * unused space. This is the amount of space needed by copy_camera_metadata for + * its dst buffer. + */ +ANDROID_API +size_t get_camera_metadata_compact_size(const camera_metadata_t *metadata); + +/** + * Get the current number of entries in the metadata packet. + * + * metadata packet must be valid, which can be checked before the call with + * validate_camera_metadata_structure(). + */ +ANDROID_API +size_t get_camera_metadata_entry_count(const camera_metadata_t *metadata); + +/** + * Get the maximum number of entries that could fit in the metadata packet. + */ +ANDROID_API +size_t get_camera_metadata_entry_capacity(const camera_metadata_t *metadata); + +/** + * Get the current count of bytes used for value storage in the metadata packet. + */ +ANDROID_API +size_t get_camera_metadata_data_count(const camera_metadata_t *metadata); + +/** + * Get the maximum count of bytes that could be used for value storage in the + * metadata packet. + */ +ANDROID_API +size_t get_camera_metadata_data_capacity(const camera_metadata_t *metadata); + +/** + * Copy a metadata structure to a memory buffer, compacting it along the + * way. That is, in the copied structure, entry_count == entry_capacity, and + * data_count == data_capacity. + * + * If dst_size > get_camera_metadata_compact_size(), the unused bytes are at the + * end of the buffer. If dst_size < get_camera_metadata_compact_size(), returns + * NULL. Otherwise returns a pointer to the metadata structure header placed at + * the start of dst. + * + * Since the buffer was not allocated by allocate_camera_metadata, the caller is + * responsible for freeing the underlying buffer when needed; do not call + * free_camera_metadata. + */ +ANDROID_API +camera_metadata_t *copy_camera_metadata(void *dst, size_t dst_size, + const camera_metadata_t *src); + + +// Non-zero return values for validate_camera_metadata_structure +enum { + CAMERA_METADATA_VALIDATION_ERROR = 1, + CAMERA_METADATA_VALIDATION_SHIFTED = 2, +}; + +/** + * Validate that a metadata is structurally sane. That is, its internal + * state is such that we won't get buffer overflows or run into other + * 'impossible' issues when calling the other API functions. + * + * This is useful in particular after copying the binary metadata blob + * from an untrusted source, since passing this check means the data is at least + * consistent. + * + * The expected_size argument is optional. + * + * Returns 0: on success + * CAMERA_METADATA_VALIDATION_ERROR: on error + * CAMERA_METADATA_VALIDATION_SHIFTED: when the data is not properly aligned, but can be + * used as input of clone_camera_metadata and the returned metadata will be valid. + * + */ +ANDROID_API +int validate_camera_metadata_structure(const camera_metadata_t *metadata, + const size_t *expected_size); + +/** + * Append camera metadata in src to an existing metadata structure in dst. This + * does not resize the destination structure, so if it is too small, a non-zero + * value is returned. On success, 0 is returned. Appending onto a sorted + * structure results in a non-sorted combined structure. + */ +ANDROID_API +int append_camera_metadata(camera_metadata_t *dst, const camera_metadata_t *src); + +/** + * Clone an existing metadata buffer, compacting along the way. This is + * equivalent to allocating a new buffer of the minimum needed size, then + * appending the buffer to be cloned into the new buffer. The resulting buffer + * can be freed with free_camera_metadata(). Returns NULL if cloning failed. + */ +ANDROID_API +camera_metadata_t *clone_camera_metadata(const camera_metadata_t *src); + +/** + * Calculate the number of bytes of extra data a given metadata entry will take + * up. That is, if entry of 'type' with a payload of 'data_count' values is + * added, how much will the value returned by get_camera_metadata_data_count() + * be increased? This value may be zero, if no extra data storage is needed. + */ +ANDROID_API +size_t calculate_camera_metadata_entry_data_size(uint8_t type, + size_t data_count); + +/** + * Add a metadata entry to a metadata structure. Returns 0 if the addition + * succeeded. Returns a non-zero value if there is insufficient reserved space + * left to add the entry, or if the tag is unknown. data_count is the number of + * entries in the data array of the tag's type, not a count of + * bytes. Vendor-defined tags can not be added using this method, unless + * set_vendor_tag_query_ops() has been called first. Entries are always added to + * the end of the structure (highest index), so after addition, a + * previously-sorted array will be marked as unsorted. + * + * Returns 0 on success. A non-0 value is returned on error. + */ +ANDROID_API +int add_camera_metadata_entry(camera_metadata_t *dst, + uint32_t tag, + const void *data, + size_t data_count); + +/** + * Sort the metadata buffer for fast searching. If already marked as sorted, + * does nothing. Adding or appending entries to the buffer will place the buffer + * back into an unsorted state. + * + * Returns 0 on success. A non-0 value is returned on error. + */ +ANDROID_API +int sort_camera_metadata(camera_metadata_t *dst); + +/** + * Get metadata entry at position index in the metadata buffer. + * Index must be less than entry count, which is returned by + * get_camera_metadata_entry_count(). + * + * src and index are inputs; the passed-in entry is updated with the details of + * the entry. The data pointer points to the real data in the buffer, and can be + * updated as long as the data count does not change. + * + * Returns 0 on success. A non-0 value is returned on error. + */ +ANDROID_API +int get_camera_metadata_entry(camera_metadata_t *src, + size_t index, + camera_metadata_entry_t *entry); + +/** + * Get metadata entry at position index, but disallow editing the data. + */ +ANDROID_API +int get_camera_metadata_ro_entry(const camera_metadata_t *src, + size_t index, + camera_metadata_ro_entry_t *entry); + +/** + * Find an entry with given tag value. If not found, returns -ENOENT. Otherwise, + * returns entry contents like get_camera_metadata_entry. + * + * If multiple entries with the same tag exist, does not have any guarantees on + * which is returned. To speed up searching for tags, sort the metadata + * structure first by calling sort_camera_metadata(). + */ +ANDROID_API +int find_camera_metadata_entry(camera_metadata_t *src, + uint32_t tag, + camera_metadata_entry_t *entry); + +/** + * Find an entry with given tag value, but disallow editing the data + */ +ANDROID_API +int find_camera_metadata_ro_entry(const camera_metadata_t *src, + uint32_t tag, + camera_metadata_ro_entry_t *entry); + +/** + * Delete an entry at given index. This is an expensive operation, since it + * requires repacking entries and possibly entry data. This also invalidates any + * existing camera_metadata_entry.data pointers to this buffer. Sorting is + * maintained. + */ +ANDROID_API +int delete_camera_metadata_entry(camera_metadata_t *dst, + size_t index); + +/** + * Updates a metadata entry with new data. If the data size is changing, may + * need to adjust the data array, making this an O(N) operation. If the data + * size is the same or still fits in the entry space, this is O(1). Maintains + * sorting, but invalidates camera_metadata_entry instances that point to the + * updated entry. If a non-NULL value is passed in to entry, the entry structure + * is updated to match the new buffer state. Returns a non-zero value if there + * is no room for the new data in the buffer. + */ +ANDROID_API +int update_camera_metadata_entry(camera_metadata_t *dst, + size_t index, + const void *data, + size_t data_count, + camera_metadata_entry_t *updated_entry); + +/** + * Retrieve human-readable name of section the tag is in. Returns NULL if + * no such tag is defined. Returns NULL for tags in the vendor section, unless + * set_vendor_tag_query_ops() has been used. + */ +ANDROID_API +const char *get_camera_metadata_section_name(uint32_t tag); + +/** + * Retrieve human-readable name of tag (not including section). Returns NULL if + * no such tag is defined. Returns NULL for tags in the vendor section, unless + * set_vendor_tag_query_ops() has been used. + */ +ANDROID_API +const char *get_camera_metadata_tag_name(uint32_t tag); + +/** + * Retrieve the type of a tag. Returns -1 if no such tag is defined. Returns -1 + * for tags in the vendor section, unless set_vendor_tag_query_ops() has been + * used. + */ +ANDROID_API +int get_camera_metadata_tag_type(uint32_t tag); + +/** + * Retrieve human-readable name of section the tag is in. Returns NULL if + * no such tag is defined. + */ +ANDROID_API +const char *get_local_camera_metadata_section_name(uint32_t tag, + const camera_metadata_t *meta); + +/** + * Retrieve human-readable name of tag (not including section). Returns NULL if + * no such tag is defined. + */ +ANDROID_API +const char *get_local_camera_metadata_tag_name(uint32_t tag, + const camera_metadata_t *meta); + +/** + * Retrieve the type of a tag. Returns -1 if no such tag is defined. + */ +ANDROID_API +int get_local_camera_metadata_tag_type(uint32_t tag, + const camera_metadata_t *meta); + +/** + * Set up vendor-specific tag query methods. These are needed to properly add + * entries with vendor-specified tags and to use the + * get_camera_metadata_section_name, _tag_name, and _tag_type methods with + * vendor tags. Returns 0 on success. + * + * **DEPRECATED** - Please use vendor_tag_ops defined in camera_vendor_tags.h + * instead. + */ +typedef struct vendor_tag_query_ops vendor_tag_query_ops_t; +struct vendor_tag_query_ops { + /** + * Get vendor section name for a vendor-specified entry tag. Only called for + * tags >= 0x80000000. The section name must start with the name of the + * vendor in the Java package style. For example, CameraZoom inc must prefix + * their sections with "com.camerazoom." Must return NULL if the tag is + * outside the bounds of vendor-defined sections. + */ + const char *(*get_camera_vendor_section_name)( + const vendor_tag_query_ops_t *v, + uint32_t tag); + /** + * Get tag name for a vendor-specified entry tag. Only called for tags >= + * 0x80000000. Must return NULL if the tag is outside the bounds of + * vendor-defined sections. + */ + const char *(*get_camera_vendor_tag_name)( + const vendor_tag_query_ops_t *v, + uint32_t tag); + /** + * Get tag type for a vendor-specified entry tag. Only called for tags >= + * 0x80000000. Must return -1 if the tag is outside the bounds of + * vendor-defined sections. + */ + int (*get_camera_vendor_tag_type)( + const vendor_tag_query_ops_t *v, + uint32_t tag); + /** + * Get the number of vendor tags supported on this platform. Used to + * calculate the size of buffer needed for holding the array of all tags + * returned by get_camera_vendor_tags(). + */ + int (*get_camera_vendor_tag_count)( + const vendor_tag_query_ops_t *v); + /** + * Fill an array with all the supported vendor tags on this platform. + * get_camera_vendor_tag_count() returns the number of tags supported, and + * tag_array should be allocated with enough space to hold all of the tags. + */ + void (*get_camera_vendor_tags)( + const vendor_tag_query_ops_t *v, + uint32_t *tag_array); +}; + +/** + * **DEPRECATED** - This should only be used by the camera framework. Camera + * metadata will transition to using vendor_tag_ops defined in + * camera_vendor_tags.h instead. + */ +ANDROID_API +int set_camera_metadata_vendor_tag_ops(const vendor_tag_query_ops_t *query_ops); + +/** + * Print fields in the metadata to the log. + * verbosity = 0: Only tag entry information + * verbosity = 1: Tag entry information plus at most 16 data values + * verbosity = 2: All information + */ +ANDROID_API +void dump_camera_metadata(const camera_metadata_t *metadata, + int fd, + int verbosity); + +/** + * Print fields in the metadata to the log; adds indentation parameter, which + * specifies the number of spaces to insert before each line of the dump + */ +ANDROID_API +void dump_indented_camera_metadata(const camera_metadata_t *metadata, + int fd, + int verbosity, + int indentation); + +/** + * Prints the specified tag value as a string. Only works for enum tags. + * Returns 0 on success, -1 on failure. + */ +ANDROID_API +int camera_metadata_enum_snprint(uint32_t tag, + uint32_t value, + char *dst, + size_t size); + +#ifdef __cplusplus +} +#endif + +#endif |