CameraCaptureSession

Discard all captures currently pending and in-progress as fast as possible.

The camera device will discard all of its current work as fast as possible. Some in-flight captures may complete successfully and call onCaptureCompleted(CameraCaptureSession, CaptureRequest, TotalCaptureResult), while others will trigger their onCaptureFailed(CameraCaptureSession, CaptureRequest, CaptureFailure) callbacks. If a repeating request or a repeating burst is set, it will be cleared.

This method is the fastest way to switch the camera device to a new session with createCaptureSession(List, CameraCaptureSession.StateCallback, Handler), at the cost of discarding in-progress work. It must be called before the new session is created. Once all pending requests are either completed or thrown away, the onReady(CameraCaptureSession) callback will be called, if the session has not been closed. Otherwise, the onClosed(CameraCaptureSession) callback will be fired when a new session is created by the camera device.

Cancelling will introduce at least a brief pause in the stream of data from the camera device, since once the camera device is emptied, the first new request has to make it through the entire camera pipeline before new output buffers are produced.

This means that using abortCaptures() to simply remove pending requests is not recommended; it's best used for quickly switching output configurations, or for cancelling long in-progress requests (such as a multi-second capture).

Submit a request for an image to be captured by the camera device.

The request defines all the parameters for capturing the single image, including sensor, lens, flash, and post-processing settings.

Each request will produce one CaptureResult and produce new frames for one or more target Surfaces, set with the CaptureRequest builder's addTarget(Surface) method. The target surfaces (set with addTarget(Surface)) must be a subset of the surfaces provided when this capture session was created.

Multiple requests can be in progress at once. They are processed in first-in, first-out order, with minimal delays between each capture. Requests submitted through this method have higher priority than those submitted through setRepeatingRequest(CaptureRequest, CameraCaptureSession.CaptureCallback, Handler) or setRepeatingBurst(List, CameraCaptureSession.CaptureCallback, Handler), and will be processed as soon as the current repeat/repeatBurst processing completes.

Submit a list of requests to be captured in sequence as a burst. The burst will be captured in the minimum amount of time possible, and will not be interleaved with requests submitted by other capture or repeat calls.

The requests will be captured in order, each capture producing one CaptureResult and image buffers for one or more target surfaces. The target surfaces (set with addTarget(Surface)) must be a subset of the surfaces provided when this capture session was created.

The main difference between this method and simply calling capture(CaptureRequest, CameraCaptureSession.CaptureCallback, Handler) repeatedly is that this method guarantees that no other requests will be interspersed with the burst.

Close this capture session asynchronously.

Closing a session frees up the target output Surfaces of the session for reuse with either a new session, or to other APIs that can draw to Surfaces.

Note that creating a new capture session with createCaptureSession(List, CameraCaptureSession.StateCallback, Handler) will close any existing capture session automatically, and call the older session listener's onClosed(CameraCaptureSession) callback. Using createCaptureSession(List, CameraCaptureSession.StateCallback, Handler) directly without closing is the recommended approach for quickly switching to a new session, since unchanged target outputs can be reused more efficiently.

Once a session is closed, all methods on it will throw an IllegalStateException, and any repeating requests or bursts are stopped (as if stopRepeating() was called). However, any in-progress capture requests submitted to the session will be completed as normal; once all captures have completed and the session has been torn down, onClosed(CameraCaptureSession) will be called.

Closing a session is idempotent; closing more than once has no effect.

Get the camera device that this session is created for.

Request endlessly repeating capture of a sequence of images by this capture session.

With this method, the camera device will continually capture images, cycling through the settings in the provided list of CaptureRequests, at the maximum rate possible.

If a request is submitted through capture(CaptureRequest, CameraCaptureSession.CaptureCallback, Handler) or captureBurst(List, CameraCaptureSession.CaptureCallback, Handler), the current repetition of the request list will be completed before the higher-priority request is handled. This guarantees that the application always receives a complete repeat burst captured in minimal time, instead of bursts interleaved with higher-priority captures, or incomplete captures.

Repeating burst requests are a simple way for an application to maintain a preview or other continuous stream of frames where each request is different in a predicatable way, without having to continually submit requests through captureBurst(List, CameraCaptureSession.CaptureCallback, Handler).

To stop the repeating capture, call stopRepeating(). Any ongoing burst will still be completed, however. Calling abortCaptures() will also clear the request.

Calling this method will replace a previously-set repeating request or burst set up by this method or setRepeatingRequest(CaptureRequest, CameraCaptureSession.CaptureCallback, Handler), although any in-progress burst will be completed before the new repeat burst will be used.

Request endlessly repeating capture of images by this capture session.

With this method, the camera device will continually capture images using the settings in the provided CaptureRequest, at the maximum rate possible.

Repeating requests are a simple way for an application to maintain a preview or other continuous stream of frames, without having to continually submit identical requests through capture(CaptureRequest, CameraCaptureSession.CaptureCallback, Handler).

Repeat requests have lower priority than those submitted through capture(CaptureRequest, CameraCaptureSession.CaptureCallback, Handler) or captureBurst(List, CameraCaptureSession.CaptureCallback, Handler), so if capture(CaptureRequest, CameraCaptureSession.CaptureCallback, Handler) is called when a repeating request is active, the capture request will be processed before any further repeating requests are processed.

To stop the repeating capture, call stopRepeating(). Calling abortCaptures() will also clear the request.

Calling this method will replace any earlier repeating request or burst set up by this method or setRepeatingBurst(List, CameraCaptureSession.CaptureCallback, Handler), although any in-progress burst will be completed before the new repeat request will be used.

Cancel any ongoing repeating capture set by either setRepeatingRequest or setRepeatingBurst(List, CameraCaptureSession.CaptureCallback, Handler). Has no effect on requests submitted through capture or captureBurst.

Any currently in-flight captures will still complete, as will any burst that is mid-capture. To ensure that the device has finished processing all of its capture requests and is in ready state, wait for the onReady(CameraCaptureSession) callback after calling this method.