EVS(Extended View System) 1.1의 카메라와 시스템 구성 관리 및 사용도 업데이트되었습니다. EVS 1.0은 카메라 기기 정보 및 시스템 구성을 쿼리하는 메서드를 제공하지 않으므로, 애플리케이션 개발자가 직접 정보를 가져와야 합니다. 예를 들어, 일부 컴퓨터 비전 애플리케이션을 구현하는 클라이언트에 카메라 보정 데이터가 있어야 합니다.
이런 상황을 완화하기 위해 EVS 1.1은 카메라 메타데이터로 카메라 기기 설명자를 확장하고 클라이언트가 카메라 기기 및 시스템 구성 정보를 가져올 수 있도록 여러 가지 방법을 제공합니다.
import android.frameworks.cameraservice.device@2.0::CameraMetadata;
import android.frameworks.cameraservice.common@2.0::CameraMetadataType;
/**
* Structure describing the basic properties of an EVS camera, extended
* from its v1.0 declaration.
*
* The HAL is responsible for filling out this structure for each
* EVS camera in the system.
*/
struct CameraDesc {
@1.0::CameraDesc v1;
/**
* Store camera metadata such as lens characteristics.
*/
CameraMetadata metadata;
};
CameraDesc가 확장되어 카메라 기기 메타데이터를 보유할 수 있으며, 이 유형은 android.frameworks.cameraservice.device@2.0에서 가져옵니다.
이러한 설계에서는 공급업체가 구현에 camera_metadata_t를 사용하고 camera_metadata.h에 정의된 API를 활용할 수 있습니다.
또한, 공급업체는 camera_vendor_tags.h에서 설명한 대로 Android에서 정의되지 않은 다른 정보를 전송하기 위해 자체 메타데이터 유형을 사용할 수 없습니다.
원하는 스트림 구성으로 카메라 기기 열기
import android.hardware.camera.device@3.2::Stream; /** * Get the IEvsCamera associated with a cameraId from a CameraDesc * * Given a camera's unique cameraId from CameraDesc, returns the * IEvsCamera interface associated with the specified camera. When * done using the camera, the caller may release it by calling closeCamera(). * * @param cameraId A unique identifier of the camera. * @param streamCfg A stream configuration the client wants to use. * @return evsCamera EvsCamera object associated with a given cameraId. */ openCamera_1_1(string cameraId, Stream streamCfg) generates (IEvsCamera evsCamera);
Android에서 정의하는 메타데이터 필드 중 하나는 ANDROID_SCALER_AVAILABLE_STREAM_CONFIGURATIONS입니다. EVS 드라이버는 이 유형을 사용하여 각 카메라 모듈에서 지원하는 스트림 구성을 식별할 수 있습니다. 예를 들어, 아래 제공된 참조 구현에는 지원되는 각 스트림 구성의 정보가 나열되어 있습니다.
- 스트림 ID
- 너비
- 높이
- 방향(입력 또는 출력)
- 프레임 속도
단일 카메라 HW 인스턴스에 있는 여러 클라이언트
클라이언트에서 이미 활성화된 카메라 기기를 열도록 요청하면 EVS 관리자는 요청된 스트림 구성과 활성 구성을 비교합니다. 서로 다른 경우, EVS 관리자는 IEvsCamera 객체를 null로 반환합니다. 클라이언트는 이러한 예상되는 실패를 적절하게 처리해야 합니다.
참조 구성 파일
EVS 1.1에 포함된 참조 구성 파일은 XML로 작성되며, 공급업체는 포함된 DTD 파일(아래 참고)을 사용하여 (수정된) 샘플 구성 파일을 검증하거나, 동일한 형식을 원할 경우 자체 구성 파일을 사용할 수 있습니다. DTD 파일은 각 요소 및 속성에 관한 자세한 설명도 제공합니다.
<?xml version='1.0' encoding='utf-8'?>
<!-- Copyright (C) 2019 The Android Open Source Project
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->
<!-- Author : changyeon@google.com
Version: 1.0
-->
<!ELEMENT configuration (system,camera,display)>
<!-- System Configuration that contains below informations:
- The dimension of the vehicle.
- Number of cameras available to EVS.
- List of predefined use cases.
-->
<!ELEMENT system (dimension,num_cameras,supported_use_case*)>
<!-- The x, y, and z dimension of the vehicle in the unit of centimeters. Axes are defined at
https://source.android.com/docs/core/interaction/sensors/sensor-types#auto_axes
-->
<!ELEMENT dimension EMPTY>
<!ATTLIST dimension
x CDATA '0'
y CDATA '0'
z CDATA '0'
>
<!-- The number of cameras that are available to EVS on the vehicle.
This must be equal to the number of camera elements of the device element.
-->
<!ELEMENT num_cameras EMPTY>
<!ATTLIST num_cameras
value CDATA #REQUIRED
>
<!-- List of predefined use cases -->
<!ELEMENT supported_use_case (use_case)*>
<!-- Predefined configurations for each of listed use cases.
@attr id : Unique string identifier of this use case.
@attr camera : ID of either a single camera device or a camera group.
@attr stream_id: Preferred stream configuration of camera device/group
that is set by camera attribute.
-->
<!ELEMENT use_case EMPTY>
<!ATTLIST use_case
id CDATA #REQUIRED
camera CDATA #REQUIRED
stream_id CDATA #REQUIRED
>
<!-- Device descriptions -->
<!ELEMENT camera (group|device)*>
<!-- Camera group descriptor
@attr group_id : Unique logical camera group identifier. Camera device use this to be
a member of the group.
@attr device_id : Comma-separated list of unique camera identifiers of member camera
devices.
@attr synchronized: Boolean field that tells whether or not this camera is synchronized
with other cameras in the same group. This will be ineffective if
there is a single camera in the group or a group is invalid.
-->
<!ELEMENT group (caps)>
<!ATTLIST group
group_id CDATA #REQUIRED
device_id CDATA #REQUIRED
synchronized CDATA #REQUIRED
>
<!-- Please note that a camera may have stream configurations. If it has, all stream
configurations must be supported by each camera device in the group.
-->
<!-- Camera device descriptor
@attr id : Unique camera identifier.
@attr position : Must be one of front, rear, left, or right.
-->
<!ELEMENT device (caps,characteristics*)>
<!ATTLIST device
id CDATA #REQUIRED
position CDATA #REQUIRED
>
<!-- Camera metadata that contains:
- A list of supported controls.
- A list of supported stream configurations.
-->
<!ELEMENT caps (supported_controls|stream)*>
<!-- A list of supported controls.
This must be a subset of android.hardware.automotive.evs@1.1::CameraParam.
-->
<!ELEMENT supported_controls EMPTY>
<!ATTLIST supported_controls
value CDATA #REQUIRED
>
<!-- A list of supported output sizes. -->
<!ELEMENT stream EMPTY>
<!ATTLIST stream
id CDATA #REQUIRED
width CDATA #REQUIRED
height CDATA #REQUIRED
format CDATA #REQUIRED
>
<!-- Camera module characteristics including its optics and imaging sensor. -->
<!ELEMENT characteristics (parameter)*>
<!ELEMENT parameter EMPTY>
<!-- A name of camera characteristic. This must be a subset of
android.hardware.automotive.evs@1.1::CameraCharacteristics.
-->
<!ATTLIST parameter
name CDATA #REQUIRED
type CDATA #REQUIRED
size CDATA #REQUIRED
value CDATA #REQUIRED
>
<!-- Available display devices -->
<!ELEMENT display (display_device)*>
<!-- Display device descriptor
@attr id : Unique display identifier.
@attr position: Display mount location.
-->
<!ELEMENT display_device (supported_formats)*>
<!ATTLIST display_device
id CDATA #REQUIRED
position CDATA #REQUIRED
>
<!-- A list of supported input data formats.
@attr value: A comma separated list of input data formats
-->
<!ELEMENT supported_formats EMPTY>
<!ATTLIST supported_formats
value CDATA #REQUIRED
>
아래는 샘플 구성 파일입니다(샘플에는 더미 수치 데이터가 포함되어 있음).
<?xml version='1.0' encoding='utf-8'?>
<!-- Copyright (C) 2019 The Android Open Source Project
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->
<!-- Extended View System Example Configuration
Android Automotive axes are used to define coordinates.
See https://source.android.com/docs/core/interaction/sensors/sensor-types#auto_axes
Use evs_configuration.dtd with xmllint tool, to validate XML configuration file
-->
<configuration>
<!-- system configuration -->
<system>
<!-- reference dimension of the vehicle in the unit of centimeters -->
<dimension x='200' y='400' z='100' />
<!-- number of cameras available to EVS -->
<num_cameras value='2'/>
<!-- list of supported use cases -->
<supported_use_case>
<!-- use case configuration -->
<use_case
id='rear_view'
camera='/dev/video1'
stream_id='1'
/>
<!-- use case configuration -->
<use_case
id='surround_view'
camera='group1'
stream_id='0'
/>
</supported_use_case>
</system>
<!-- camera device information -->
<camera>
<!-- camera group 0 -->
<group group_id='group0'
device_id='/dev/video1,/dev/video2'
synchronized='false'
>
<caps>
<stream id='0' width='640' height='360' format='V4L2_PIX_UYUV'/>
</caps>
</group>
<!-- camera device starts -->
<device id='/dev/video1' position='rear'>
<caps>
<!-- list of supported controls -->
<supported_controls
value='BRIGHTNESS,
CONTRAST,
AUTO_WHITE_BALANCE,
WHITE_BALANCE_TEMPERATURE,
SHARPNESS,
AUTO_EXPOSURE,
ABSOLUTE_EXPOSURE,
AUTO_FOCUS,
ABSOLUTE_ZOOM'
/>
<!-- list of supported stream configurations -->
<stream id='0' width='1280' height='1080' format='V4L2_PIX_NV21'/>
<stream id='1' width='1280' height='1080' format='V4L2_PIX_YUYV'/>
<stream id='2' width='1280' height='1080' format='V4L2_PIX_UYUV'/>
<stream id='3' width='640' height='360' format='V4L2_PIX_NV21'/>
<stream id='4' width='640' height='360' format='V4L2_PIX_YUYV'/>
<stream id='5' width='640' height='360' format='V4L2_PIX_UYUV'/>
<stream id='6' width='320' height='240' format='V4L2_PIX_NV21'/>
<stream id='7' width='320' height='240' format='V4L2_PIX_YUYV'/>
<stream id='8' width='320' height='240' format='V4L2_PIX_UYUV'/>
</caps>
<!-- list of parameters -->
<characteristics>
<!-- Lens distortion information. See
https://developer.android.com/reference/android/hardware/camera2/CameraCharacteristics.html#LENS_DISTORTION
-->
<parameter
name='LENS_DISTORTION'
type='float'
size='5'
value='0.0,0.0,0.0,0.0,0.0'
/>
<!-- Camera intrinsic calibration matrix. See
https://developer.android.com/reference/android/hardware/camera2/CameraCharacteristics.html#LENS_INTRINSIC_CALIBRATION
-->
<parameter
name='LENS_INTRINSIC_CALIBRATION'
type='float'
size='5'
value='0.0,0.0,0.0,0.0,0.0'
/>
<!-- Camera pose translation and rotation. See
https://developer.android.com/reference/android/hardware/camera2/CameraCharacteristics.html#LENS_POSE_TRANSLATION
https://developer.android.com/reference/android/hardware/camera2/CameraCharacteristics.html#LENS_POSE_ROTATION
-->
<parameter
name='LENS_POSE_TRANSLATION'
type='float'
size='3'
value='0.0,0.0,0.0'
/>
<parameter
name='LENS_POSE_ROTATION'
type='float'
size='4'
value='0.0,0.0,0.0,0.0'
/>
</characteristics>
</device>
<device id='/dev/video2' position='front'>
<caps>
<!-- list of supported stream configurations -->
<stream id='0' width='1280' height='1080' format='V4L2_PIX_NV21'/>
</caps>
</device>
</camera>
<!-- display device starts -->
<display>
<display_device id='display0' position='driver'>
<!-- list of supported input formats
This must be a subset of android_pixel_format_t enum.
-->
<supported_formats
value='RGBA_8888,
YUYV,
UYVY'
/>
</display_device>
</display>
</configuration>