The android.hardware.camera2 package provides an interface to
individual camera devices connected to an Android device. It replaces
the deprecated Camera
class.
This package models a camera device as a pipeline, which takes in input requests for capturing a single frame, captures the single image per the request, and then outputs one capture result metadata packet, plus a set of output image buffers for the request. The requests are processed in-order, and multiple requests can be in flight at once. Since the camera device is a pipeline with multiple stages, having multiple requests in flight is required to maintain full framerate on most Android devices.
To enumerate, query, and open available camera devices, obtain a
CameraManager
instance.
Individual CameraDevices
provide a set of static property information that
describes the hardware device and the available settings and output
parameters for the device. This information is provided through the
CameraCharacteristics
object, and is
available through getCameraCharacteristics(String)
To capture or stream images from a camera device, the application
must first create a camera capture session
with a set of output Surfaces for use with the camera device, with
createCaptureSession(List
. Each
Surface has to be pre-configured with an appropriate
size and format
(if applicable) to match the sizes and formats
available from the camera device. A target Surface can be obtained
from a variety of classes, including SurfaceView
,
SurfaceTexture
via
Surface(SurfaceTexture)
,
MediaCodec
, MediaRecorder
,
Allocation
, and ImageReader
.
Generally, camera preview images are sent to SurfaceView
or TextureView
(via its
SurfaceTexture
). Capture of JPEG images or
RAW buffers for DngCreator
can be done
with ImageReader
with the
{android.graphics.ImageFormat#JPEG} and
{android.graphics.ImageFormat#RAW_SENSOR} formats. Application-driven
processing of camera data in RenderScript, OpenGL ES, or directly in
managed or native code is best done through Allocation
with a YUV Type
, SurfaceTexture
,
and ImageReader
with a
{android.graphics.ImageFormat#YUV_420_888} format, respectively.
The application then needs to construct a CaptureRequest
, which defines all the
capture parameters needed by a camera device to capture a single
image. The request also lists which of the configured output Surfaces
should be used as targets for this capture. The CameraDevice has a
factory method
for creating a request builder
for a
given use case, which is optimized for the Android device the
application is running on.
Once the request has been set up, it can be handed to the active
capture session either for a one-shot capture
or for
an endlessly repeating
use. Both methods also have a variant that accepts a list
of requests to use as a burst capture / repeating burst. Repeating
requests have a lower priority than captures, so a request submitted
through capture()
while there's a repeating request
configured will be captured before any new instances of the currently
repeating (burst) capture will begin capture.
After processing a request, the camera device will produce a TotalCaptureResult
object, which contains
information about the state of the camera device at time of capture,
and the final settings used. These may vary somewhat from the request,
if rounding or resolving contradictory parameters was necessary. The
camera device will also send a frame of image data into each of the
output Surfaces
included in the request. These are produced
asynchronously relative to the output CaptureResult, sometimes
substantially later.
CameraCaptureSession | A configured capture session for a CameraDevice , used for capturing
images from the camera. |
CameraCaptureSession.CaptureListener | A listener for tracking the progress of a |
CameraCaptureSession.StateListener | A listener for tracking the state of a camera capture session. |
CameraCharacteristics | The properties describing a
|
CameraCharacteristics.Key<T> | A Key is used to do camera characteristics field lookups with
get(CameraCharacteristics.Key . |
CameraDevice | The CameraDevice class is a representation of a single camera connected to an Android device, allowing for fine-grain control of image capture and post-processing at high frame rates. |
CameraDevice.CaptureListener |
This class is deprecated.
Use CameraCaptureSession.CaptureListener instead
|
CameraDevice.StateListener | A listener for notifications about the state of a camera device. |
CameraManager | A system service manager for detecting, characterizing, and connecting to
|
CameraManager.AvailabilityListener | A listener for camera devices becoming available or unavailable to open. |
CameraMetadata<TKey> | The base class for camera controls and information. |
CaptureFailure | A report of failed capture for a single image capture from the image sensor. |
CaptureRequest | An immutable package of settings and outputs needed to capture a single image from the camera device. |
CaptureRequest.Builder | A builder for capture requests. |
CaptureRequest.Key<T> | A Key is used to do capture request field lookups with
get(CaptureResult.Key or to set fields with
set(Key, Object) . |
CaptureResult | The subset of the results of a single image capture from the image sensor. |
CaptureResult.Key<T> | A Key is used to do capture result field lookups with
get(CaptureResult.Key . |
DngCreator | The DngCreator class provides functions to write raw pixel data as a DNG file. |
TotalCaptureResult | The total assembled results of a single image capture from the image sensor. |
CameraAccessException |
|