/* SPDX-License-Identifier: Apache-2.0 */ /* * 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