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和你一起终身学习，这里是程序员Android
经典好文推荐，通过阅读本文，您将收获以下知识点:
一、Systrace 拆解概览
二、Systrace 阶段拆解详解
一、Systrace 拆解概览
MTK Camera 照片切换视频trace 拆解(非切换摄像头类)
| 照片切换视频 | 模块 | trace 关键字 |
|---|---|---|
| S0 | Camera APP | deliverInputEvent ⇒ abortCaptures/CameraHal::flush 开始 |
| S1 | Camera HAL | abortCaptures/CameraHal::flush |
| S2 | Camera APP | abortCaptures/CameraHal::flush 结束 ⇒ CameraHal::configureStreams start |
| S3 | Camera HAL | CameraHal::configureStreams |
| S4 | Camera APP | CameraHal::configureStreams end ⇒ setRepeatingRequest start |
| S5 | Camera HAL | setRepeatingRequest start ⇒ first full buffer |
| S6 | Camera APP、SF | first full buffer ⇒ 第一帧显示(onPreviewOk) |
二、Systrace 阶段拆解详解
2.1 点击照片模式切换视频模式
S0 deliverInputEvent ⇒ abortCapture/CameraHal::flush 开始
Camera 响应点击事件开始abortCapture
Systrace 关键字：
Camera app 点击照片切换视频模式响应：deliverInputEvent
Camera app 下发停止预览请求：abortCaptures
Camera FWK 响应abortcapture 的处理： flush 、CameraHal::flush
S1 abortCaptures/CameraHal::flush
CameraHAL 响应flush的流程
StreamingNode flush
Systrace 关键字：
StreamingNode::flush
P2_Dispatch:notifyFlush()
P2_Streaming:notifyFlush()
P2_Dispatch:waitFlush()
P2_Streaming:waitFlush()
CaptureNode flush
Systrace 关键字：
CaptureNode::flush
P2_Capture:notifyFlush()
P2_Capture:waitFlush()
S2 abortCaptures/CameraHal::flush 结束 ⇒ CameraHal::configureStreams start
初始化videomode,MediaRecorder ，prepare MediaRecorder
Systrace 关键字：
videoMode.doInitMode
AIDL::cpp::ICameraService::getNumberOfCameras::cppClient
videoMode.mediaRecorderinit
videoMode.mediaRecorderPrepare
Camera APP通过bind 跟mediaserver 进行通讯，并创建createRecord
createRecord 实例
AIDL::cpp::IAudioFlingerService::createRecord::cppClient
S3 CameraHal::configureStreams
configureStreams 概览
Systrace 关键字：
createCaptureSession
endConfigure
configureStreams
configureStreamsLocked
CameraHal::configureStreams
Delete3路照片流
Systrace 关键字：
deleteStream
disconnect
freeBuffer
创建3路视频流
Systrace 关键字：
AIDL::cpp::ICameraDeviceUser::createStream::cppServer
createStream
Camera HAL CaptureNode ，StreamNode uninit
Systrace 关键字：
StreamingNode::flush
CaptureNode::flush
CaptureNode::uninit
StreamingNode::uninit
StreamingNode flush && CaptureNode flush
StreamingNode flush
Systrace 关键字：
StreamingNode::flush
P2_Dispatch:waitFlush()
P2_Streaming:waitFlush()
P2_Dispatch:notifyFlush()
P2_Streaming:notifyFlush()
CaptureNode flush
Systrace 关键字：
CaptureNode::flush
P2_Capture:waitFlush()
P2_Capture:notifyFlush()
CaptureNode uninit &&StreamingNode uninit
CaptureNode uninit
CaptureNode::uninit
P2_Capture:uninit()
StreamingNode uninit
StreamingNode::uninit
P2_Dispatch:uninit()
P2_Streaming:uninit()
releaseGeneralPipe
uninit
uninitPool
fpipe.p2g.fullImg.destroy
~GraphicBuffer
free
freeBuffer
TPI uninit
uninitHalISP
StreamingNode::uninitLock
uninit3DNR
uninitDsdnPools
releaseBuffer
fpipe.fullImg.destroy
uninitNodes
uninitSMVR
Camera HAL 决策配流Feature evaluateConfiguration
Systrace 关键字：
configureStreams
eatureSettingPolicy::evaluateConfiguration
evaluateCaptureConfiguration
updateStreamConfiguration
为申请的3路视频流申请buffers
Systrace 关键字：
configureStreams
initProducer-Hal:Image:FD
initProducer-Hal:Image:P1:Resizeraw_main1
initProducer-Hal:Image:STT_main1
allocateBuffers
endConfigure dump
Camera FWK 配流结束 finishConfiguration
Systrace 关键字：
endConfigure
finishConfiguration
Camera FWK 配流结束 finishConfiguration 的同时 FdNode init
,StreamNode init,CaptureNode init
Systrace 关键字：
finishConfiguration
FdNode init
StreamingNode::init
CaptureNode::init
submitRequestList
StreamingNode::init
Systrace 关键字：
StreamingNode::init
P2_Dispatch:init()
P2_Streaming:FeaturePipe create
prepareGeneralPipe
P2_Streaming:FeaturePipe init
TPI init_config
CaptureNode::init && config
Systrace 关键字：
CaptureNode::init
P2_Capture:init()
P2_Capture:FeaturePipe create & init
CaptureNode::config
P2_Capture:config()
S4：CameraHal::configureStreams 结束 -->submitRequestList
CameraHal::configureStreams 结束 -->submitRequestList 下发预览请求 trace TAG
submitRequestList 下发预览请求
Sysrace TAG:
AIDL::cpp::ICameraDeviceUser::submitRequestList::cppServer
submitRequestList
setStreamingRequestList
submitRequestsHelper
setRepeatingRequests
S5：submitRequestList --> first full buffer
第一帧预览请求
第一帧预览请求 Trace
Camera FWK trace TAG：sendRequestsBatchCameraHal::processBatchCaptureRequestsframe capture
Camera HAL trace TAG：processCaptureRequest
第一帧出图callback 请求
第一帧出图定位： callback Camera FWK 关键trace TAG
Trace TAG:processCaptureResultsStream 0: first full buffer
第一帧出图callback Camera HAL --> Camera FWK -->Camera APP
第一帧callback 流程（Camera HAL -->Camera FWK）
第一帧出图callback Camera HAL trace TAGprocessCaptureResult
第一帧出图callback Camera FWK 关键 trace TAG：first full bufferStream 0: first full bufferframe capture
第一帧callback 流程（Camera FWK -->Camera APP）
Camera APP trace TAG:SurfaceTexture
S6： first full buffer ⇒ 第一帧显示(onPreviewOk)
第一帧callback 流程（Camera APP -->SurfaceFliger 送显示）
SF 显示trace TAG：surfaceflingervsync-sfBufferTxFence
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