7.5. Cameras

If device implementations include at least one camera, they:

  • [C-1-1] MUST declare the android.hardware.camera.any feature flag.
  • [C-1-2] MUST be possible for an application to simultaneously allocate 3 RGBA_8888 bitmaps equal to the size of the images produced by the largest-resolution camera sensor on the device, while camera is open for the purpose of basic preview and still capture.
  • [C-1-3] MUST ensure that the preinstalled default camera application handling intents MediaStore.ACTION_IMAGE_CAPTURE, MediaStore.ACTION_IMAGE_CAPTURE_SECURE, or MediaStore.ACTION_VIDEO_CAPTURE, is responsible for removing the user location in the image metadata before sending it to the receiving application when the receiving application does not have ACCESS_FINE_LOCATION.

7.5.1. Rear-Facing Camera

A rear-facing camera is a camera located on the side of the device opposite the display; that is, it images scenes on the far side of the device, like a traditional camera.

Device implementations:

  • SHOULD include a rear-facing camera.

If device implementations include at least one rear-facing camera, they:

  • [C-1-1] MUST report the feature flag android.hardware.camera and android.hardware.camera.any.
  • [C-1-2] MUST have a resolution of at least 2 megapixels.
  • SHOULD have either hardware auto-focus or software auto-focus implemented in the camera driver (transparent to application software).
  • MAY have fixed-focus or EDOF (extended depth of field) hardware.
  • MAY include a flash.

If the camera includes a flash:

  • [C-2-1] the flash lamp MUST NOT be lit while an android.hardware.Camera.PreviewCallback instance has been registered on a Camera preview surface, unless the application has explicitly enabled the flash by enabling the FLASH_MODE_AUTO or FLASH_MODE_ON attributes of a Camera.Parameters object. Note that this constraint does not apply to the device’s built-in system camera application, but only to third-party applications using Camera.PreviewCallback.

7.5.2. Front-Facing Camera

A front-facing camera is a camera located on the same side of the device as the display; that is, a camera typically used to image the user, such as for video conferencing and similar applications.

Device implementations:

  • MAY include a front-facing camera.

If device implementations include at least one front-facing camera, they:

  • [C-1-1] MUST report the feature flag android.hardware.camera.any and android.hardware.camera.front.
  • [C-1-2] MUST have a resolution of at least VGA (640x480 pixels).
  • [C-1-3] MUST NOT use a front-facing camera as the default for the Camera API and MUST NOT configure the API to treat a front-facing camera as the default rear-facing camera, even if it is the only camera on the device.
  • [C-1-4] The camera preview MUST be mirrored horizontally relative to the orientation specified by the application when the current application has explicitly requested that the Camera display be rotated via a call to the android.hardware.Camera.setDisplayOrientation() method. Conversely, the preview MUST be mirrored along the device’s default horizontal axis when the current application does not explicitly request that the Camera display be rotated via a call to the android.hardware.Camera.setDisplayOrientation() method.
  • [C-1-5] MUST NOT mirror the final captured still image or video streams returned to application callbacks or committed to media storage.
  • [C-1-6] MUST mirror the image displayed by the postview in the same manner as the camera preview image stream.
  • MAY include features (such as auto-focus, flash, etc.) available to rear-facing cameras as described in section 7.5.1.

If device implementations are capable of being rotated by user (such as automatically via an accelerometer or manually via user input):

  • [C-2-1] The camera preview MUST be mirrored horizontally relative to the device’s current orientation.

7.5.3. External Camera

Device implementations:

  • MAY include support for an external camera that is not necessarily always connected.

If device implementations include support for an external camera, they:

  • [C-1-1] MUST declare the platform feature flag android.hardware.camera.external and android.hardware camera.any.
  • [C-1-2] MUST support USB Video Class (UVC 1.0 or higher) if the external camera connects through the USB host port.
  • [C-1-3] MUST pass camera CTS tests with a physical external camera device connected. Details of camera CTS testing are available at source.android.com.
  • SHOULD support video compressions such as MJPEG to enable transfer of high-quality unencoded streams (i.e. raw or independently compressed picture streams).
  • MAY support multiple cameras.
  • MAY support camera-based video encoding.

If camera-based video encoding is supported:

  • [C-2-1] A simultaneous unencoded / MJPEG stream (QVGA or greater resolution) MUST be accessible to the device implementation.

7.5.4. Camera API Behavior

Android includes two API packages to access the camera, the newer android.hardware.camera2 API expose lower-level camera control to the app, including efficient zero-copy burst/streaming flows and per-frame controls of exposure, gain, white balance gains, color conversion, denoising, sharpening, and more.

The older API package,android.hardware.Camera, is marked as deprecated in Android 5.0 but as it should still be available for apps to use. Android device implementations MUST ensure the continued support of the API as described in this section and in the Android SDK.

All features that are common between the deprecated android.hardware.Camera class and the newer android.hardware.camera2 package MUST have equivalent performance and quality in both APIs. For example, with equivalent settings, autofocus speed and accuracy must be identical, and the quality of captured images must be the same. Features that depend on the different semantics of the two APIs are not required to have matching speed or quality, but SHOULD match as closely as possible.

Device implementations MUST implement the following behaviors for the camera-related APIs, for all available cameras. Device implementations:

  • [C-0-1] MUST use android.hardware.PixelFormat.YCbCr_420_SP for preview data provided to application callbacks when an application has never called android.hardware.Camera.Parameters.setPreviewFormat(int).
  • [C-0-2] MUST further be in the NV21 encoding format when an application registers an android.hardware.Camera.PreviewCallback instance and the system calls the onPreviewFrame() method and the preview format is YCbCr_420_SP, the data in the byte[] passed into onPreviewFrame(). That is, NV21 MUST be the default.
  • [C-0-3] MUST support the YV12 format (as denoted by the android.graphics.ImageFormat.YV12 constant) for camera previews for both front- and rear-facing cameras for android.hardware.Camera. (The hardware video encoder and camera may use any native pixel format, but the device implementation MUST support conversion to YV12.)
  • [C-0-4] MUST support the android.hardware.ImageFormat.YUV_420_888 and android.hardware.ImageFormat.JPEG formats as outputs through the android.media.ImageReader API for android.hardware.camera2 devices that advertise REQUEST_AVAILABLE_CAPABILITIES_BACKWARD_COMPATIBLE capability in android.request.availableCapabilities.
  • [C-0-5] MUST still implement the full Camera API included in the Android SDK documentation, regardless of whether the device includes hardware autofocus or other capabilities. For instance, cameras that lack autofocus MUST still call any registered android.hardware.Camera.AutoFocusCallback instances (even though this has no relevance to a non-autofocus camera.) Note that this does apply to front-facing cameras; for instance, even though most front-facing cameras do not support autofocus, the API callbacks must still be “faked” as described.
  • [C-0-6] MUST recognize and honor each parameter name defined as a constant in the android.hardware.Camera.Parameters class and the android.hardware.camera2.CaptureRequest class. Conversely, device implementations MUST NOT honor or recognize string constants passed to the android.hardware.Camera.setParameters() method other than those documented as constants on the android.hardware.Camera.Parameters. That is, device implementations MUST support all standard Camera parameters if the hardware allows, and MUST NOT support custom Camera parameter types. For instance, device implementations that support image capture using high dynamic range (HDR) imaging techniques MUST support camera parameter Camera.SCENE_MODE_HDR.
  • [C-0-7] MUST report the proper level of support with the android.info.supportedHardwareLevel property as described in the Android SDK and report the appropriate framework feature flags.
  • [C-0-8] MUST also declare its individual camera capabilities of android.hardware.camera2 via the android.request.availableCapabilities property and declare the appropriate feature flags; MUST define the feature flag if any of its attached camera devices supports the feature.
  • [C-0-9] MUST broadcast the Camera.ACTION_NEW_PICTURE intent whenever a new picture is taken by the camera and the entry of the picture has been added to the media store.
  • [C-0-10] MUST broadcast the Camera.ACTION_NEW_VIDEO intent whenever a new video is recorded by the camera and the entry of the picture has been added to the media store.
  • [C-0-11] MUST have all cameras accessible via the deprecated android.hardware.Camera API also accessible via the android.hardware.camera2 API.
  • [C-SR] For devices with multiple RGB cameras facing in the same direction, are STRONGLY RECOMMENDED to support a logical camera device that lists capability CameraMetadata.REQUEST_AVAILABLE_CAPABILITIES_LOGICAL_MULTI_CAMERA, consisting of all of the RGB cameras facing that direction as physical sub-devices.

If device implementations provide a proprietary camera API to 3rd-party apps, they:

7.5.5. Camera Orientation

If device implementations have a front- or a rear-facing camera, such camera(s):

  • [C-1-1] MUST be oriented so that the long dimension of the camera aligns with the screen’s long dimension. That is, when the device is held in the landscape orientation, cameras MUST capture images in the landscape orientation. This applies regardless of the device’s natural orientation; that is, it applies to landscape-primary devices as well as portrait-primary devices.