ArTrackData

External data track, used by Recording and Playback API.

Summary

Typedefs
ArTrackData typedef
struct ArTrackData_
Data that has been recorded to an external track.
ArTrackDataList typedef
struct ArTrackDataList_
A list of ArTrackData.

Functions
ArTrackDataList_acquireItem(const ArSession *session, const ArTrackDataList *track_data_list, int32_t index, ArTrackData **out_track_data)
void
Acquires a reference to an indexed entry in the list.
ArTrackDataList_create(const ArSession *session, ArTrackDataList **out_track_data_list)
void
Creates an ArTrackDataList object.
ArTrackDataList_destroy(ArTrackDataList *track_data_list)
void
Releases the memory used by the ArTrackData list object.
ArTrackDataList_getSize(const ArSession *session, const ArTrackDataList *track_data_list, int32_t *out_size)
void
Retrieves the number of ArTrackData elements in the list.
ArTrackData_getData(const ArSession *session, const ArTrackData *track_data, const uint8_t **out_data, int32_t *out_size)
void
Retrieves the ArTrackData byte data that was recorded by ArFrame_recordTrackData.
ArTrackData_getFrameTimestamp(const ArSession *session, const ArTrackData *track_data, int64_t *out_timestamp_ns)
void
Retrieves the timestamp in nanoseconds of the frame the given ArTrackData was recorded on.
ArTrackData_release(ArTrackData *track_data)
void
Releases a reference to a ArTrackData.

Typedefs

ArTrackData

struct ArTrackData_ ArTrackData

Data that has been recorded to an external track.

ArTrackDataList

struct ArTrackDataList_ ArTrackDataList

A list of ArTrackData.

Functions

ArTrackDataList_acquireItem

void ArTrackDataList_acquireItem(
  const ArSession *session,
  const ArTrackDataList *track_data_list,
  int32_t index,
  ArTrackData **out_track_data
)

Acquires a reference to an indexed entry in the list.

This call must eventually be matched with a call to ArTrackData_release.

Details
Parameters
session
The ARCore session
track_data_list
The list being queried
index
The index of the list
out_track_data
The pointer to the ArTrackData acquired at the given index in the list

ArTrackDataList_create

void ArTrackDataList_create(
  const ArSession *session,
  ArTrackDataList **out_track_data_list
)

Creates an ArTrackDataList object.

Details
Parameters
session
The ARCore session
out_track_data_list
The pointer to the list to be initialized

ArTrackDataList_destroy

void ArTrackDataList_destroy(
  ArTrackDataList *track_data_list
)

Releases the memory used by the ArTrackData list object.

Details
Parameters
track_data_list
The pointer to the ArTrackDataList memory being released

ArTrackDataList_getSize

void ArTrackDataList_getSize(
  const ArSession *session,
  const ArTrackDataList *track_data_list,
  int32_t *out_size
)

Retrieves the number of ArTrackData elements in the list.

Details
Parameters
session
The ARCore session.
track_data_list
The list being checked for size
out_size
The size of the list, 0 if track_data_list is empty

ArTrackData_getData

void ArTrackData_getData(
  const ArSession *session,
  const ArTrackData *track_data,
  const uint8_t **out_data,
  int32_t *out_size
)

Retrieves the ArTrackData byte data that was recorded by ArFrame_recordTrackData.

The pointer returned by this function is valid until ArTrackData_release is called.

Details
Parameters
session
The ARCore session
track_data
The ArTrackData to pull the data from
out_data
The pointer to the ArTrackDataList byte data being populated. Will point to an empty list if no data present
out_size
The number of bytes that were populated in out_data, 0 if list is empty

ArTrackData_getFrameTimestamp

void ArTrackData_getFrameTimestamp(
  const ArSession *session,
  const ArTrackData *track_data,
  int64_t *out_timestamp_ns
)

Retrieves the timestamp in nanoseconds of the frame the given ArTrackData was recorded on.

This timestamp is equal to the result of ArFrame_getTimestamp on the frame during which the track data was written.

Details
Parameters
session
The ARCore session
track_data
The ArTrackData to pull the timestamp from
out_timestamp_ns
The int64_t timestamp value to be set

ArTrackData_release

void ArTrackData_release(
  ArTrackData *track_data
)

Releases a reference to a ArTrackData.

Acquire a ArTrackData with ArTrackDataList_acquireItem.

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

Details
Parameters
track_data
The ArTrackData being released