ArImageMetadata

Provides access to CPU image camera metadata.

Summary

Typedefs
ArImageMetadata	typedef struct ArImageMetadata_ Camera capture metadata (reference type, large data).
ArImageMetadata_const_entry	typedef struct ArImageMetadata_const_entry Defines a single read-only image metadata entry.
ArImageMetadata_rational	typedef struct ArImageMetadata_rational Defines a rational data type in ArImageMetadata_const_entry.

Functions
ArImageMetadata_getAllKeys(const ArSession *session, const ArImageMetadata *image_metadata, int32_t *out_number_of_tags, const uint32_t **out_tags)	void Retrieves the list of the supported image metadata tags that can be queried for their value.
ArImageMetadata_getConstEntry(const ArSession *session, const ArImageMetadata *image_metadata, uint32_t tag, ArImageMetadata_const_entry *out_metadata_entry)	ArStatus Get a metadata entry for the provided ArImageMetadata and tag.
ArImageMetadata_release(ArImageMetadata *metadata)	void Releases a reference to the metadata.

Structs
ArImageMetadata_const_entry	Defines a single read-only image metadata entry.
ArImageMetadata_rational	Defines a rational data type in ArImageMetadata_const_entry.

Typedefs

ArImageMetadata

struct ArImageMetadata_ ArImageMetadata

Camera capture metadata (reference type, large data).

• Acquire with: ArFrame_acquireImageMetadata
• Release with: ArImageMetadata_release

ArImageMetadata_const_entry

struct ArImageMetadata_const_entry ArImageMetadata_const_entry

Defines a single read-only image metadata entry.

Struct matches ACameraMetadata_const_entry in Android NDK r21.

ArImageMetadata_rational

struct ArImageMetadata_rational ArImageMetadata_rational

Defines a rational data type in ArImageMetadata_const_entry.

Struct matches ACameraMetadata_rational in Android NDK r21.

Functions

ArImageMetadata_getAllKeys

void ArImageMetadata_getAllKeys(
  const ArSession *session,
  const ArImageMetadata *image_metadata,
  int32_t *out_number_of_tags,
  const uint32_t **out_tags
)

Retrieves the list of the supported image metadata tags that can be queried for their value.

The out_tags list remains valid until image_metadata is released via ArImageMetadata_release.

Details
Parameters	session The ARCore session. image_metadata ArImageMetadata struct obtained from ArFrame_acquireImageMetadata. out_number_of_tags Number of metadata tags returned in the list. out_tags The data pointer to the beginning of the list of uint32_t tags.

ArImageMetadata_getConstEntry

ArStatus ArImageMetadata_getConstEntry(
  const ArSession *session,
  const ArImageMetadata *image_metadata,
  uint32_t tag,
  ArImageMetadata_const_entry *out_metadata_entry
)

Get a metadata entry for the provided ArImageMetadata and tag.

The returned out_metadata_entry remains valid until the provided image_metadata is released via ArImageMetadata_release.

Details
Parameters	session The ARCore session. image_metadata ArImageMetadata struct obtained from ArFrame_acquireImageMetadata. tag The desired uint32_t metadata tag to be retrieved from the provided ArImageMetadata struct. out_metadata_entry The ArImageMetadata_const_entry struct to which the metadata tag data should be written to, updated only when function returns AR_SUCCESS.
Returns	AR_SUCCESS or any of: AR_ERROR_INVALID_ARGUMENT - if either session, image_metadata or out_metadata_entry is null. AR_ERROR_METADATA_NOT_FOUND - if image_metadata does not contain an entry of the tag value.

ArImageMetadata_release

void ArImageMetadata_release(
  ArImageMetadata *metadata
)

Releases a reference to the metadata.

This must match a call to ArFrame_acquireImageMetadata.

This function may safely be called with NULL - it will do nothing.