The Recording & Playback API enables you to record video and AR data once within a given environment and use that content to replace a live camera session.
Prerequisites
Make sure that you understand fundamental AR concepts and how to configure an ARCore session before proceeding.
Compatibility with other ARCore APIs
Due to the way session data is processed, ARCore APIs may produce different results during playback than observed during recording. They may also produce different results during subsequent playback sessions. For example, the number of detected trackables, the precise timing of their detection, and their poses over time may be different during playback.
Compatibility with Cloud Anchors
You can host and resolve Cloud Anchors while recording or playing back a session.
Recording
Start, stop, and check the status of an ARCore session recording.
Record an ARCore session
To record an entire ARCore session, call
Session.StartRecording().
This method will fail if a recording is already in progress. Recording may
continue even if the session is paused. If this happens, ARCore will continue to
capture sensor data, while recording the camera feed as a black screen.
ARCoreRecordingConfig config = new ARCoreRecordingConfig();
config.Mp4DatasetFilepath = "path/to/file.mp4";
Session.StartRecording(config);
Stop a recording
To stop recording, call
Session.StopRecording().
Session.StopRecording();
Check recording status
ARRecordingManager.RecordingStatus
can be used at any time to determine the current RecordingStatus.
Debug.Log("Current Recording Status: " + Session.RecordingStatus);
Playback
Play back previously recorded AR sessions. Sessions play back in real time, and session playback or speed cannot be adjusted.
Play back a previously recorded session
To play back a previously recorded session, call Session.SetPlaybackDataset() and provide a file path for the dataset you wish to play back. You must pause the session to use this method. Resume the session for the change to take effect.
Once playback has started, pausing the session by by disabling the ARCoreSession will suspend processing of all camera image frames and any other recorded sensor data in the dataset. Camera image frames and sensor frame data that is discarded in this way will not be reprocessed when the session is again resumed by re-enabling the ARCoreSession. AR tracking for the session will generally suffer due to the gap in processed data.
// Pause the current session when providing the path.
session.enabled = false;
// In the next frame, provide a filepath for the dataset you wish to play back.
session.SetPlaybackDataset("path/to/file.mp4");
// In the frame after that, resume the session.
session.enabled = true;
Restart playback from the beginning
To restart a playback from the beginning of the dataset, pause the session and call Session.SetPlaybackDataset(), specifying the same MP4 recording before resuming the session.
// Pause the current session when re-setting the path.
session.enabled = false;
// In the next frame, specify the same dataset.
session.SetPlaybackDataset(filepath); // filepath is the same path you used before
// In the frame after that, resume playback from the beginning of the dataset.
session.enabled = true;
Play back a different session
To play back a different dataset, call Session.SetPlaybackDataset() and specify a new
dataset before resuming the session.
// Pause the current session when re-setting the path.
session.enabled = false;
// In the next frame, specify a new dataset.
session.SetPlaybackDataset(newFilepath); // newFilepath is a different path than the one you used before
// In the frame after that, resume playback from the beginning of the new dataset.
session.enabled = true;
Check playback status
ARPlaybackManager.PlaybackStatus
can be used at any time to determine the current playback status.
Debug.Log("Current Playback Status: " + session.PlaybackStatus);
What’s next
- Learn how to add custom data to recorded sessions.