一、camx的代码结构

  目前主流的机型都使用camx架构,这个架构和之前架构的主要区别就是 芯片接口层的代码从hardware/qcom 迁移到 vendor/qcom/proprietary/下面,
  我们主要关注的camera hal层的源码也是放在vendor/qcom/proprietary/camx/下面。
  Android : Camera之camx hal架构-LMLPHP

二、camx 编译:

  camx的核心目录是 vendor/qcom/proprietary/camx/src/ 目录下面:

total
drwxrwxr-x lxl lxl 4月 : ./
drwxrwxr-x lxl lxl 4月 : ../
drwxrwxr-x lxl lxl 4月 : chiiqutils/
drwxrwxr-x lxl lxl 4月 : core/
drwxrwxr-x lxl lxl 4月 : csl/
drwxrwxr-x lxl lxl 4月 : hwl/
drwxrwxr-x lxl lx 4月 : lib/
drwxrwxr-x lxl lxl 4月 : osutils/
drwxrwxr-x lxl lxl 4月 : swl/
drwxrwxr-x lxl lxl 4月 : utils/

  核心的Android.mk在 ./lib/build/android/Android.mk 中。
  其中包括的静态库如下:

# Libraries to link
LOCAL_STATIC_LIBRARIES :=   \
    libcamxcore             \
    libcamxchi              \
    libcamxcsl              \
    libcamxofflinestats     \
    libnc                   \
    libcamxncs              \
    libifestriping          \
    libstriping LOCAL_WHOLE_STATIC_LIBRARIES := \
    libcamxdspstreamer          \
    libcamxhwlbps               \
    libcamxgenerated            \
    libcamxhal                  \
    libcamxhalutils             \
    libcamxhwlfd                \
    libcamxhwlife               \
    libcamxhwlipe               \
    libcamxhwliqmodule          \
    libcamxswlfdmanager         \
    libcamxswljpeg              \
    libcamxhwljpeg              \
    libcamxhwllrme              \
    libcamxswlransac            \
    libcamxhwltitan17x          \
    libcamxiqsetting            \
    libcamxosutils              \
    libcamxstats                \
    libcamxsensor               \
    libcamxutils

  这些静态库都是camx或者其他的目录下编译的,编译工程的时候,我们要先编译这些静态库,然后编译camx的动态库(/vendor/lib/hw/camera.qcom.so)。

三、camx 代码流程分析:

  camera.provider中如何实现到camera hal层的跳跃,camera service调用到camera provider中的接口方法,现在调用到 camera provider中的 hardware/interfaces/camera/device/3.2/default/CameraDeviceSession.cpp 中的processCaptureRequest(...)方法,最终会调用到:
  status_t ret = mDevice->ops->process_capture_request(mDevice, &halRequest);
  这个mDevice->ops 就是 hardware/libhardware/include/hardware/camera3.h 中的 camera3_device_ops 结构体: (参考:https://www.jianshu.com/p/099cc3b0ab25

typedef struct camera3_device_ops {
int (*initialize)(const struct camera3_device *,
const camera3_callback_ops_t *callback_ops);
int (*configure_streams)(const struct camera3_device *,
camera3_stream_configuration_t *stream_list);
int (*register_stream_buffers)(const struct camera3_device *,
const camera3_stream_buffer_set_t *buffer_set);
const camera_metadata_t* (*construct_default_request_settings)(
const struct camera3_device *,
int type);
int (*process_capture_request)(const struct camera3_device *,
camera3_capture_request_t *request);
void (*get_metadata_vendor_tag_ops)(const struct camera3_device*,
vendor_tag_query_ops_t* ops);
void (*dump)(const struct camera3_device *, int fd);
int (*flush)(const struct camera3_device *); /* reserved for future use */
void *reserved[];
} camera3_device_ops_t;

  camera3_device_ops_t 映射函数指针操作: hardware/libhardware/modules/camera/3_0/Camera.cpp

const camera3_device_ops_t Camera::sOps = {
.initialize = default_camera_hal::initialize,
.configure_streams = default_camera_hal::configure_streams,
.register_stream_buffers = default_camera_hal::register_stream_buffers,
.construct_default_request_settings
= default_camera_hal::construct_default_request_settings,
.process_capture_request = default_camera_hal::process_capture_request,
.get_metadata_vendor_tag_ops = NULL,
.dump = default_camera_hal::dump,
.flush = default_camera_hal::flush,
.reserved = {},
};

  这样找到在camera hal层的函数指针的映射关系。
  映射到:vendor/qcom/proprietary/camx/src/core/hal/camxhal3entry.cpp 中的:

  // Global dispatch
  static Dispatch g_dispatchHAL3(&g_jumpTableHAL3);
/// Array containing camera3_device_ops_t methods
static camera3_device_ops_t g_camera3DeviceOps =
{
CamX::initialize,
CamX::configure_streams,
NULL,
CamX::construct_default_request_settings,
CamX::process_capture_request,
NULL,
CamX::dump,
CamX::flush,
{},
};
  定义了g_camera3DeviceOps变量:
/// Array containing camera3_device_ops_t methods
static camera3_device_ops_t g_camera3DeviceOps =
{
CamX::initialize,
CamX::configure_streams,
NULL,
CamX::construct_default_request_settings,
CamX::process_capture_request,
NULL,
CamX::dump,
CamX::flush,
{},
};

  并在\vendor\qcom\proprietary\camx\src\core\hal\camxhaldevice.cpp的Initialize方法中通过GetCamera3DeviceOps获取,建立联系:

CamxResult HALDevice::Initialize(
const HwModule* pHwModule,
UINT32 cameraId)
{
CamxResult result = CamxResultSuccess; m_cameraId = cameraId; if (CamxResultSuccess == result)
{
m_camera3Device.hwDevice.tag = HARDWARE_DEVICE_TAG; /// @todo (CAMX-351) Get from local macro
m_camera3Device.hwDevice.version = CAMERA_DEVICE_API_VERSION_3_3;
m_camera3Device.hwDevice.close = reinterpret_cast<CloseFunc>(GetHwDeviceCloseFunc());
m_camera3Device.pDeviceOps = reinterpret_cast<Camera3DeviceOps*>(GetCamera3DeviceOps());
m_camera3Device.pPrivateData = this;
// NOWHINE CP036a: Need exception here
m_camera3Device.hwDevice.pModule = const_cast<HwModule*>(pHwModule); m_HALCallbacks.ProcessCaptureResult = ProcessCaptureResult;
m_HALCallbacks.NotifyResult = Notify;
CamX::ChiOverrideBypass(&m_HALCallbacks);
} m_pHALSession = NULL;
Utils::Memset(m_flushRequest, , sizeof(m_flushRequest)); return result;
}

  看一下g_jumpTableHAL3 变量:在 vendor/qcom/proprietary/camx/src/core/hal/camxhal3.cpp 中定义的:

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Jump table for HAL3
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
JumpTableHAL3 g_jumpTableHAL3 =
{
open,
get_number_of_cameras,
get_camera_info,
set_callbacks,
get_vendor_tag_ops,
open_legacy,
set_torch_mode,
init,
parallelQuery,
setCallBack,
get_tag_count,
get_all_tags,
get_section_name,
get_tag_name,
get_tag_type,
close,
initialize,
configure_streams,
construct_default_request_settings,
process_capture_request,
dump,
flush,
camera_device_status_change,
torch_mode_status_change,
process_capture_result,
notify
};

  这儿直接构成了指针函数的映射关系(对应camxhaldevice.cpp中的函数)。

  vendor/qcom/proprietary/camx/src/core/chi/camxchitypes.h中定义了CHIAppCallbacks结构体,如下:

struct CHIAppCallbacks
{
/// @brief Called by the driver to get number of cameras
INT(*CHIGetNumCameras)(
UINT32* pNumFwCameras,
UINT32* pNumLogicalCameras); /// @brief Called by the driver to get the camera info for the camera id
CamxResult (*CHIGetCameraInfo)(
UINT32 cameraId,
CameraInfo* pCameraInfo); /// @brief Defines the prototype for the device status change callback method from to the framework. Please refer to
/// the camera_device_status_change documentation in hardware/camera_common.h.
VOID (*CHIInitializeOverrideSession)(
UINT32 cameraId,
const Camera3Device* pCamera3Device,
const HALCallbacks* pHALCallbacks,
Camera3StreamConfig* pStreamConfig,
BOOL* isOverrideEnabled,
VOID** ppPrivate); /// @brief Defines the prototype for the torch mode status change callback method from to the framework. Please refer to
/// the torch_mode_status_change documentation in hardware/camera_common.h.
VOID (*CHIFinalizeOverrideSession)(
const Camera3Device* pCamera3Device,
UINT64* pSession,
VOID** ppPrivate); /// @brief Called by the driver to inform about session closing
VOID (*CHITeardownOverrideSession)(
const Camera3Device* pCamera3Device,
UINT64* pSession,
VOID* pPrivate); /// @brief Called by the driver to pass on capture request call to CHI
INT (*CHIOverrideProcessRequest)(
const Camera3Device* pCamera3Device,
Camera3CaptureRequest* pCaptureRequest,
VOID* pPrivate); /// @brief Called by the driver to allow for additional override processing during open()
INT(*CHIExtendOpen)(
UINT32 cameraId,
VOID* pPrivateData); /// @brief Called by the driver to allow for additional override processing during close()
INT(*CHIExtendClose)(
UINT32 cameraId,
VOID* pPrivateData); /// @brief Called by the driver to allow override to remap special camera IDs into logical camera IDs
UINT32(*CHIRemapCameraId)(
UINT32 frameworkCameraId,
CameraIdRemapMode mode); /// @brief Interface to allow various override-specific settings to be toggled.
UINT32(*CHIModifySettings)(
VOID* pPrivateData); /// @brief Get any vendor tag specific request settings the override wants to get added to the default settings
VOID (*CHIGetDefaultRequestSettings)(
UINT32 frameworkCameraId,
INT requestTemplate,
const Metadata** pAdditionalMetadata); /// @brief Called by the driver to allow for flush()
INT(*CHIOverrideFlush)(
const Camera3Device* pCamera3Device);
INT(*CHIParallelQuery) (INT num, char* list[]);
INT(*CHISetCallback) (void*); }; typedef VOID(*CHIHALOverrideEntry)(
CHIAppCallbacks* pCHIAppCallbacks);

  这个结构体是函数指针,映射关系:
  vendor/qcom/proprietary/camx/src/core/hal/camxhal3module.h 中定义了 CHIAppCallbacks m_ChiAppCallbacks;

    CHIAppCallbacks       m_ChiAppCallbacks;                    ///< CHI HAL override entry

  vendor/qcom/proprietary/camx/src/core/hal/camxhal3module.cpp中的 HAL3Module构造函数中,存在下面的执行语句:

CHIHALOverrideEntry funcCHIHALOverrideEntry =
reinterpret_cast<CHIHALOverrideEntry>(
CamX::OsUtils::LibGetAddr(m_hChiOverrideModuleHandle, "chi_hal_override_entry")); if (NULL != funcCHIHALOverrideEntry)
{
funcCHIHALOverrideEntry(&m_ChiAppCallbacks); //对应到 chxextensioninterface.cpp 中的chi_hal_override_entry函数 CAMX_ASSERT(NULL != m_ChiAppCallbacks.CHIGetNumCameras);
CAMX_ASSERT(NULL != m_ChiAppCallbacks.CHIGetCameraInfo);
CAMX_ASSERT(NULL != m_ChiAppCallbacks.CHIFinalizeOverrideSession);
CAMX_ASSERT(NULL != m_ChiAppCallbacks.CHIInitializeOverrideSession);
CAMX_ASSERT(NULL != m_ChiAppCallbacks.CHIOverrideProcessRequest);
CAMX_ASSERT(NULL != m_ChiAppCallbacks.CHIOverrideFlush);
CAMX_ASSERT(NULL != m_ChiAppCallbacks.CHITeardownOverrideSession);
CAMX_ASSERT(NULL != m_ChiAppCallbacks.CHIExtendOpen);
CAMX_ASSERT(NULL != m_ChiAppCallbacks.CHIExtendClose);
CAMX_ASSERT(NULL != m_ChiAppCallbacks.CHIRemapCameraId);
CAMX_ASSERT(NULL != m_ChiAppCallbacks.CHIModifySettings);
CAMX_ASSERT(NULL != m_ChiAppCallbacks.CHIParallelQuery);
CAMX_ASSERT(NULL != m_ChiAppCallbacks.CHISetCallback); if ((NULL != m_ChiAppCallbacks.CHIGetNumCameras) &&
(NULL != m_ChiAppCallbacks.CHIGetCameraInfo) &&
(NULL != m_ChiAppCallbacks.CHIFinalizeOverrideSession) &&
(NULL != m_ChiAppCallbacks.CHIInitializeOverrideSession) &&
(NULL != m_ChiAppCallbacks.CHIOverrideProcessRequest) &&
(NULL != m_ChiAppCallbacks.CHIOverrideFlush) &&
(NULL != m_ChiAppCallbacks.CHITeardownOverrideSession) &&
(NULL != m_ChiAppCallbacks.CHIExtendOpen) &&
(NULL != m_ChiAppCallbacks.CHIExtendClose) &&
(NULL != m_ChiAppCallbacks.CHIRemapCameraId) &&
(NULL != m_ChiAppCallbacks.CHIModifySettings) &&
(NULL != m_ChiAppCallbacks.CHIParallelQuery) &&
(NULL != m_ChiAppCallbacks.CHISetCallback))
{
CAMX_LOG_WARN(CamxLogGroupHAL, "CHI Module library function pointers exchanged");
}
}

  m_ChiAppCallbacks 通过 funcCHIHALOverrideEntry 映射到 chi_hal_override_entry这个 chi_hal_override_entry 就是指 vendor/qcom/proprietary/chi-cdk/vendor/chioverride/default/chxextensioninterface.cpp 中的 chi_hal_override_entry 函数,如下:

void chi_hal_override_entry(
chi_hal_callback_ops_t* callbacks)
{
ExtensionModule* pExtensionModule = ExtensionModule::GetInstance(); CHX_ASSERT(NULL != callbacks); if (NULL != pExtensionModule)
{
callbacks->chi_get_num_cameras = chi_get_num_cameras;
callbacks->chi_get_camera_info = chi_get_camera_info;
callbacks->chi_initialize_override_session = chi_initialize_override_session;
callbacks->chi_finalize_override_session = chi_finalize_override_session;
callbacks->chi_override_process_request = chi_override_process_request;
callbacks->chi_teardown_override_session = chi_teardown_override_session;
callbacks->chi_extend_open = chi_extend_open;
callbacks->chi_extend_close = chi_extend_close;
callbacks->chi_remap_camera_id = chi_remap_camera_id;
callbacks->chi_modify_settings = chi_modify_settings;
callbacks->chi_get_default_request_settings = chi_get_default_request_settings;
callbacks->chi_override_flush = chi_override_flush;
callbacks->chi_parallelquery = chi_parallelquery;
callbacks->chi_setcallback = chi_setcallback;
}
}

  这样就建立了 CHIAppCallbacks 中函数指针的一一映射关系。

  Android : Camera之camx hal架构-LMLPHP

  vendor/qcom/proprietary/chi-cdk/vendor/chioverride/default/chxextensionmodule.cpp 中的 ExtensionModule::OverrideProcessRequest 函数中执行了 m_pUsecaseFactory->CreateUsecaseObject,如下:

m_pSelectedUsecase[logicalCameraId] =
m_pUsecaseFactory->CreateUsecaseObject(&m_logicalCameraInfo[logicalCameraId],
static_cast<UsecaseId>(m_SelectedUsecaseId[logicalCameraId]),
m_pStreamConfig[logicalCameraId]);

  直接调用到: vendor/qcom/proprietary/chi-cdk/vendor/chioverride/default/chxusecaseutils.cpp 中的 UsecaseFactory::CreateUsecaseObject 函数:

Usecase* UsecaseFactory::CreateUsecaseObject(
LogicalCameraInfo* pLogicalCameraInfo, ///< camera info
UsecaseId usecaseId, ///< Usecase Id
camera3_stream_configuration_t* pStreamConfig) ///< Stream config
{
Usecase* pUsecase = NULL;
UINT camera0Id = pLogicalCameraInfo->ppDeviceInfo[]->cameraId;
CHX_LOG_ERROR("UsecaseFactory::CreateUsecaseObject id = %d", usecaseId);
switch (usecaseId)
{
case UsecaseId::PreviewZSL:
pUsecase = AdvancedCameraUsecase::Create(pLogicalCameraInfo, pStreamConfig, usecaseId);
break;
case UsecaseId::MultiCamera:
pUsecase = UsecaseMultiCamera::Create(pLogicalCameraInfo, pStreamConfig);
break;
case UsecaseId::MultiCameraVR:
pUsecase = UsecaseMultiVRCamera::Create(pLogicalCameraInfo, pStreamConfig);
break;
case UsecaseId::MFNR:
pUsecase = UsecaseMFNR::Create(camera0Id, pStreamConfig);
break;
case UsecaseId::QuadCFA:
pUsecase = UsecaseQuadCFA::Create(pLogicalCameraInfo, pStreamConfig);
break;
case UsecaseId::Torch:
pUsecase = UsecaseTorch::Create(camera0Id, pStreamConfig);
break;
default:
pUsecase = AdvancedCameraUsecase::Create(pLogicalCameraInfo, pStreamConfig, usecaseId);
break;
} return pUsecase;
}
enum class UsecaseId
{
NoMatch = ,
Default = ,
Preview = ,
PreviewZSL = ,
MFNR = ,
MFSR = ,
MultiCamera = ,
QuadCFA = ,
RawJPEG = ,
MultiCameraVR = ,
Torch = ,
YUVInBlobOut = ,
MaxUsecases = ,
};

  前置摄像头的UsecaseId是 PreviewZSL,是单摄,后置摄像头的UsecaseId是 MultiCamera,是多摄。

  Android : Camera之camx hal架构-LMLPHP

  camx-usecase

  Android : Camera之camx hal架构-LMLPHP

  vendor/qcom/proprietary/camx/src/core/chi/camxchi.cpp中的 ChiEntry函数如下:

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/// ChiEntry
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
CAMX_VISIBILITY_PUBLIC VOID ChiEntry(
ChiContextOps* pChiContextOps)
{
if (NULL != pChiContextOps)
{
pChiContextOps->size = sizeof(ChiContextOps); pChiContextOps->majorVersion = CHI_API_MAJOR_VERSION;
pChiContextOps->minorVersion = CHI_API_MINOR_VERSION;
pChiContextOps->pOpenContext = CamX::ChiOpenContext;
pChiContextOps->pCloseContext = CamX::ChiCloseContext;
pChiContextOps->pGetNumCameras = CamX::ChiGetNumCameras;
pChiContextOps->pGetCameraInfo = CamX::ChiGetCameraInfo;
pChiContextOps->pEnumerateSensorModes = CamX::ChiEnumerateSensorModes;
pChiContextOps->pCreatePipelineDescriptor = CamX::ChiCreatePipelineDescriptor;
pChiContextOps->pDestroyPipelineDescriptor = CamX::ChiDestroyPipelineDescriptor;
pChiContextOps->pCreateSession = CamX::ChiCreateSession;
pChiContextOps->pDestroySession = CamX::ChiDestroySession;
pChiContextOps->pFlushSession = CamX::ChiFlushSession;
pChiContextOps->pActivatePipeline = CamX::ChiActivatePipeline;
pChiContextOps->pDeactivatePipeline = CamX::ChiDeactivatePipeline;
pChiContextOps->pSubmitPipelineRequest = CamX::ChiSubmitPipelineRequest;
pChiContextOps->pTagOps = CamX::ChiGetTagOps;
} // This is the workaround for presil HAL3test on Windows
// On Device, set_camera_metadata_vendor_ops will be call the set the
// static vendor tag operation in camera_metadata.c
//
// On Windows side, theoretically hal3test should mimic what Android framework
// does and call the set_camera_metadata_vendor_ops function in libcamxext library
// However, in Windows, if both hal3test.exe and hal.dll link to libcamxext library,
// there are two different instance of static varibles sit in different memory location.
// Even if set_camera_metadata_vendor_ops is called in hal3test, when hal try to
// access to vendor tag ops, it is still not set.
//
// This is also a workaround to call vendor tag ops in Chi at GetNumCameras which happens to get called before
// GetVendorTagOps
CamX::g_vendorTagOps.get_all_tags = CamX::ChiGetAllTags;
CamX::g_vendorTagOps.get_section_name = CamX::ChiGetSectionName;
CamX::g_vendorTagOps.get_tag_count = CamX::ChiGetTagCount;
CamX::g_vendorTagOps.get_tag_name = CamX::ChiGetTagName;
CamX::g_vendorTagOps.get_tag_type = CamX::ChiGetTagType; set_camera_metadata_vendor_ops(&(CamX::g_vendorTagOps));
}

  这个函数映射关系很重要,也在camx chi中比较常见,直接映射在此文件的CamxChi类中。都是从 vendor/qcom/proprietary/chi-cdk/vendor/chioverride/default/chxextensionmodule.cpp中调用过来的。

  下面是预览时capture request 处理流程图:

  Android : Camera之camx hal架构-LMLPHP

 check这段流程的时候我们最关注应该是5个重要的处理类型:

1.UseCase , vendor/qcom/proprietary/chi-cdk/vendor/chioverride/default/chxusecase.h 上面有介绍类图。UseCase在camx中很有很多衍生类,这是camx针对不同的stream来建立不同的usecase对象,用来管理选择feature,并且创建 pipeline以及session。
    2.ChiFeature, vendor/qcom/proprietary/chi-cdk/vendor/chioverride/default/chxfeature.h, usecase选择相应的feature,关联一组pipeline,收到request请求,根据request选择对应的feature。
    3.Node , vendro/qcom/propriatary/camx/src/core/camxnode.h ,下面有类图。Node是camx中非常重要的一个父类,是camx中处理camera 请求的一个中间节点,用于处理pipeline下发的请求,下面有类图介绍,比较重要**的Node子类已经标出来了。
    4.pipeline , 一连串node的集合,通过pipeline下发给各个node处理。
    5.session , 若干个有关联的pipeline的集合,用来管理pipeline,使用pipeline处理请求。

 注: Node 节点在camx chi架构中至关重要,数据的处理都是通过封装好的Node节点来进行的。

  Android : Camera之camx hal架构-LMLPHP

  camxnode结构图:

  Android : Camera之camx hal架构-LMLPHP

  

  node节点的创建地方在vendor/qcom/proprietary/camx/src/hwl/titian17x/camxtitian17xfactory.cpp

Node* Titan17xFactory::HwCreateNode(
const NodeCreateInputData* pCreateInputData,
NodeCreateOutputData* pCreateOutputData
) const
{
Node* pNode = NULL; switch (pCreateInputData->pNodeInfo->nodeId)
{
case AutoFocus:
pNode = AutoFocusNode::Create(pCreateInputData, pCreateOutputData);
break;
case BPS:
pNode = BPSNode::Create(pCreateInputData, pCreateOutputData);
break;
case IFE:
pNode = IFENode::Create(pCreateInputData, pCreateOutputData);
break;
case IPE:
pNode = IPENode::Create(pCreateInputData, pCreateOutputData);
break;
case Sensor:
pNode = SensorNode::Create(pCreateInputData, pCreateOutputData);
break;
case StatsProcessing:
pNode = StatsProcessingNode::Create(pCreateInputData, pCreateOutputData);
break;
case JPEG:
pNode = JPEGEncNode::Create(pCreateInputData, pCreateOutputData);
break;
case JPEGAggregator:
pNode = JPEGAggrNode::Create(pCreateInputData, pCreateOutputData);
break;
case StatsParse:
pNode = StatsParseNode::Create(pCreateInputData, pCreateOutputData);
break;
case ChiExternalNode:
pNode = ChiNodeWrapper::Create(pCreateInputData, pCreateOutputData);
break;
case FDHw:
pNode = FDHwNode::Create(pCreateInputData, pCreateOutputData);
break;
case FDManager:
pNode = FDManagerNode::Create(pCreateInputData, pCreateOutputData);
break;
case OfflineStats:
pNode = OfflineStatsNode::Create(pCreateInputData, pCreateOutputData);
break;
case Torch:
pNode = TorchNode::Create(pCreateInputData, pCreateOutputData);
break;
case LRME:
pNode = LRMENode::Create(pCreateInputData, pCreateOutputData);
break;
case RANSAC:
pNode = RANSACNode::Create(pCreateInputData, pCreateOutputData);
break;
default:
CAMX_ASSERT_ALWAYS_MESSAGE("Unexpected node type");
break;
} return pNode;
}

  Android : Camera之camx hal架构-LMLPHP

  camx_feature:

  Android : Camera之camx hal架构-LMLPHP

  在 vendor/qcom/proprietary/chi-cdk/vendor/chioverride/default/chxadvancedcamerausecase.cpp中的SelectFeatures(...)函数中有这些feature的创建代码。 

  拍照的场景分为前置和后置,前置是单摄,后置是多摄,前面也有介绍,单摄和多摄使用的usecase是不同:

  前置拍照创建的pipeline有:

MiuiZSLSnapshotJpeg at index  for session , session's pipeline 0, camera id:1
MiuiZSLPreviewRaw at index for session , session's pipeline 0, camera id:1
BinningZSLYuv2Jpeg at index for session , session's pipeline 0, camera id:1
BinningMerge3YuvCustomTo1Yuv at index for session , session's pipeline 0, camera id:1
ZSLSnapshotYUV at index for session , session's pipeline 0, camera id:1
AdvancedAsdMeta at index for session , session's pipeline 0, camera id:1
SWMFClearShotYuv at index for session , session's pipeline 0, camera id:1
BinningZSLSnapshotYUV at index for session , session's pipeline 0, camera id:1

  后置拍照创建的pipeline有:

BackCameraJpegEncode at index  for session , session's pipeline 0, camera id:0
MfnrPrefilter at index for session , session's pipeline 1, camera id:0
MfnrBlend at index for session , session's pipeline 2, camera id:0
MfnrPostFilter at index for session , session's pipeline 3, camera id:0
MfnrScale at index for session , session's pipeline 4, camera id:0
Merge3YuvCustomTo1Yuv at index for session , session's pipeline 0, camera id:0
ZSLSnapshotYUV at index for session , session's pipeline 0, camera id:0
ZSLSnapshotYUVAux at index for session , session's pipeline 0, camera id:3
SWMFSRYuv at index for session , session's pipeline 0, camera id:0
AdvancedAsdMeta at index for session , session's pipeline 0, camera id:0

  pipeline在camx中的配置文件是:vendor/qcom/proprietary/chi-cdk/vendor/topology/default/titan17x_usecases.xml,编译时会根据此xml的配置生成对应vendor\qcom\proprietary\chi-cdk\vendor\chioverride\default\g_pipelines.h,
  vendor\qcom\proprietary\chi-cdk\vendor\chioverride\default\build\android\Android.mk:

...
$(info $(shell perl $(CAMX_CDK_PATH)/topology/usecaseconverter.pl $(CAMX_VENDOR_PATH)/topology/default/titan17x_usecases.xml $(LOCAL_PATH)/g_pipelines.h))
...

  然后在\vendor\qcom\proprietary\chi-cdk\vendor\chioverride\default\chxusecaseutils.cpp中会根据pStreamConfig->num_streams选择到对应的Usecases(g_pipelines.h中定义):

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// UsecaseSelector::DefaultMatchingUsecase
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
ChiUsecase* UsecaseSelector::DefaultMatchingUsecase(
camera3_stream_configuration_t* pStreamConfig)
{
...
  pSelectedUsecase = &pChiTargetUsecases->pChiUsecases[i];
... }

  DefaultMatchingUsecase方法即在 \vendor\qcom\proprietary\chi-cdk\vendor\chioverride\default\chxadvancedcamerausecase.cpp 被调用:

CDKResult AdvancedCameraUsecase::SelectUsecaseConfig(
LogicalCameraInfo* pCameraInfo, ///< Camera info
camera3_stream_configuration_t* pStreamConfig) ///< Stream configuration
{
...
m_pChiUsecase = UsecaseSelector::DefaultMatchingUsecase(pStreamConfig);
...
}

四、调试:

修改 \vendor\qcom\proprietary\camx\src\core\camxsettings.xml 设置 log 打印级别,如:

overrideLogLevels=0x1F
logInfoMask=0x40080
logVerboseMask=0x40000

-end-

05-03 20:48