第14讲 从CameraServer角度详解Camera启动性能 - Android Camera性能分析

本讲是Android Camera性能分析专题的第14讲，我们介绍从CameraServer角度详解Camera启动性能，包括如下内容：

1. 从CameraServer角度详解Camera启动性能
2. CameraServer核心函数流程拆解

视频在线观看：

• 极客笔记：
  https://app5d5waway1614.h5.xiaoeknow.com/p/course/column/p_6252b815e4b01a4851ef948a?type=3

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从CameraServer角度详解Camera启动性能

模块	开始点	结束点
App	点击Camera App Icon	开始调用connectDevice
HAL	开始调用connectDevice	调用connectDevice结束
App	调用connectDevice结束	开始调用endConfigure
HAL	开始调用endConfigure	调用endConfigure结束
App	调用endConfigure结束	调用submitRequestList
HAL	调用submitRequestList	CameraServer收到第一帧

CameraServer核心函数流程拆解

getCameraCharacteristics

1.shouldRejectSystemCameraConnection
2.getCameraCharacteristicsLocked // 从CameraProviderManager中获取CameraCharacteristics
3.getCameraCharacteristics::checkPermission

connectDevice

会调用到HAL的CameraHal::openSession

1.validateConnectLocked
2.CameraDeviceClient::initializeImpl
      Camera2ClientBase::initializeImpl
            Camera3Device::initialize
                CameraHal::openSession
3.finishConnectLocked

createDefaultRequest

会调用到HAL的CameraHal::constructDefaultRequestSettings

1.CameraDeviceClient::createDefaultRequest
    Camera3Device::createDefaultRequest
        CameraHal::constructDefaultRequestSettings

beginConfigure

CameraDeviceClient::beginConfigure //Not implemented yet

createStream

核心在创建 Camera3OutputStream

CameraDeviceClient::createStream
    SessionConfigurationUtils::createSurfaceFromGbp
        query(width,height,format,dataspace)
    Camera3Device::createStream
        new Camera3OutputStream
    setStreamTransformLocked

endConfigure

会调用到HAL的CameraHal::configureStreams

CameraDeviceClient::endConfigure
    Camera3Device::configureStreams
        Camera3Stream::startConfiguration
        CameraHal::configureStreams
        Camera3Stream::finishConfiguration
        Boost priority of request thread to SCHED_FIFO

submitRequestList

CaptureRequest送下来后会等待Active

CameraDeviceClient::submitRequestList
    Camera3Device::setStreamingRequestList
        Camera3Device::RequestThread::setRepeatingRequests
        Camera3Device::waitUntilStateThenRelock

Request thread线程开始给HAL送Request，调用 CameraHal::processBatchCaptureRequests

Camera3Device::RequestThread::threadLoop
    Camera3Device::RequestThread::waitForNextRequestBatch
    Camera3Device::RequestThread::prepareHalRequests
    Camera3Device::RequestThread::sendRequestsBatch
        CameraHal::processBatchCaptureRequests

StatusTracker通知status变化：

Camera3Device::notifyStatus
    Camera3Device::internalUpdateStatusLocked
        mStatusChanged.broadcast
        Camera2ClientBase<TClientBase>::notifyActive
            CameraService::BasicClient::startCameraStreamingOps

Stream 0: first full buffer

HAL回调processCaptureResult后，如果有Buffer，则取出来 queueBuffer给 Consumer

Camera3Device::processCaptureResult
  Camera3OutputUtils::returnAndRemovePendingOutputBuffers
    Camera3OutputUtils::returnOutputBuffers
      Camera3Stream::returnBuffer
        Camera3OutputStream::returnBufferLocked
          Camera3IOStreamBase::returnAnyBufferLocked
            Camera3OutputStream::returnBufferCheckedLocked
              Camera3OutputStream::queueBufferToConsumer