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、MFNR 简介
二、MFNR 开关与决策
三、MFNR 相关的adb 命令
四、MFNR log 分析
五 参考文献
一、MFNR 简介
MFNR : Multiple Frame Noise Reduction
MFLL : Multiple Frame Low Light
BSS : Best Select Shot
MFNR 跟 MFLL 是两个功能一致，名称不同的简称，是MTK 推出的YUV domain 多帧降噪的算法。
MFNR 是在 P2_CaputureNode 中 CaptureFeaturePipe 的路径，多帧的raw 首先在 rootnode 中做 bss，同时会做 recorder 动作，然后依次进入到 P2ANode 做 raw2yuv ，产生的yuv等image，送到 MultiFrameNode（挂载 MFNR 算法）中进行多帧降噪处理，产生一张降噪后的YUV；如果还挂在其他的单帧YUV算法，则送YUVNode 处理，最终送到MDPNode 做crop ，resize处理；
大致流程如下：
Raws--> RootNode(BSS)-->Raws-->P2A(Raw2Yuv)-->YUVs-->MultiFrameNode(MFNR)-->YUV-->YUVNode-->YUV-->MDPNode-->Yuv
二、MFNR 开关与决策
2.1 MFNR 开关设置
开关控制在：MTK_CAM_MFB_SUPPORT
代码路径：/device/*/ProjectConfig.mk
如果支持，默认建议设置为 3
MTK_CAM_MFB_SUPPORT =3
0: 关 MFLL 1：开 MFLL2：开 AIS 3：开 MFLL 和AIS1.不支持MFNR时，请在 app 中设置
MTK_MFNR_FEATURE_MFB_MODE 为 MTK_MFNR_FEATURE_MFB_OFF
2.支持MFNR 时，请在 app 中设置
MTK_MFNR_FEATURE_MFB_MODE 为 MTK_MFNR_FEATURE_MFB_AUTO，由 CUST_MFLL_AUTO_MODE 决策走哪个模式
3.当支持AIS时，可以使用下面二者任一种
1.MTK_MFNR_FEATURE_AIS_MODE = MTK_MFNR_FEATURE_AIS_ON
2.MTK_MFNR_FEATURE_MFB_MODE = MTK_MFNR_FEATURE_MFB_AIS
4.当前面的meta确认为非 OFF 状态，则去判断tuning设置的threshold 是否满足，(mfll_iso_th 决策是否走MFNR)。
三、MFNR 相关的adb 命令
1.强制开、关 MFNR
adb shell setprop vendor.mfll.force 1 // 开 ：1 、 关：0
2. dump MFNR 各阶段的图片
adb shell setprop vendor.mfll.dump.all 1
路径：/data/vendor/camera_dump
3.开MFNR 的log
adb shell setprop vendor.mfll.log_level 3
4.dump MFNR 需要的RaW 跟YUV 图
adb shell setprop vendor.debug.camera.p2.dump 1
5.dump bss 之前的RAW和RRZO
adb shell setprop vendor.debug.camera.bss.dump 1
四、MFNR log 分析
Log 关键字
log关键字：MFNRPlugin|capture req|capture intent: 2|connect call|MfllCore
connect call|capture req|capture intent: 2|mfll_iso_th.*enablemfb|Mfll apply.*frames|Collected Selection|capture request frames count|BSS output|skip frame count|allocate memory|times to blend|funcprocessMemc|process.*collected request|doMsBlending|process.*callback request
| 关键字 | 解释 |
|---|---|
| connect call | 调用cameraservice的app 以及使用的api |
| capture req capture intent: 2 | 拍照请求帧以及intent |
| MFNRPlugin | MFNR |
| origin_iso | 838 当前预览iso |
| mfll_iso_th:100 | 多帧 iso 决策 ， |
| enableMfb:1 | 开启 mfll |
| frameCapture:4 | 多帧拍照张数4张 |
| evaluateCaptureSetting | 拍照决策 mainFrame:1 subFrames:3 |
| BSS output | BSS 选帧 |
| BSS: skip frame | 过BSS 算法 skip的张数 |
| allocate memory | 分配内存 |
| collected request(0/4) | MFNR 收到帧的张数 |
| doMsBlending | 多帧融合 |
| callback request | 依次 callback 每一帧 |
// 水印相机
04-10 16:41:04.080150 1422 8639 I CameraService: CameraService::connect call (PID 8414 "com.tencent.zebra", camera ID 0) and Camera API version 1
// capture req#:92 capture intent: 2 第 92 帧 请求拍照
04-10 16:41:09.544396 1478 9201 D mtkcam_hal_android.device: [capture intent: 2] + ULog#158932
04-10 16:41:09.544453 1478 9201 D mtkcam_hal_android.device: [ASettingRuleHelper::updateLogicalSetting] capture intent: 2
04-10 16:41:09.544487 1478 9201 D mtkcam_hal_android.device: [capture intent: 2] - ULog#158933
04-10 16:41:09.545722 1478 9201 I mtkcam-FeatureSettingPolicy: [collectCaptureInfo] (0xb400007a86f4af30) capture req#:92
04-10 16:41:09.548862 1478 9201 D MFNRPlugin: (9201)[negotiate] Collected Selection:(0/0), ISP mode: 0, sensorId:0, Req(92)// origin_iso:838 但前预览iso
// mfll_iso_th:100 多帧 iso 决策 ，
// enableMfb:1 开启 mfll
// frameCapture:4 多帧拍照张数4张
04-10 16:41:09.549907 1478 9201 I MfllCore/Strategy: {Mfll}[queryStrategy] iso:838, origin_iso:838, mfll_iso_th:100, downscale(enabled:0, ratio:0, 16/16), finalCfg(enableMfb:1, frameCapture:4), postrefine(nr:1, mfb:1), aevc(ae:0, lcso:0)
04-10 16:41:09.550055 1478 9201 D MFNRCapability_Basic: (9201)[updateSelection] Mfll apply = 1, frames = 4
04-10 16:41:09.550410 1478 9201 D MFNRPlugin: (9201)[negotiate] Collected Selection:(1/0), ISP mode: 0, sensorId:0, Req(92)
04-10 16:41:09.550512 1478 9201 D MFNRCapability_Basic: (9201)[updateSelection] Mfll apply = 1, frames = 4
04-10 16:41:09.550784 1478 9201 D MFNRPlugin: (9201)[negotiate] Collected Selection:(2/0), ISP mode: 0, sensorId:0, Req(92)
04-10 16:41:09.550857 1478 9201 D MFNRCapability_Basic: (9201)[updateSelection] Mfll apply = 1, frames = 4
04-10 16:41:09.551145 1478 9201 D MFNRPlugin: (9201)[negotiate] Collected Selection:(3/0), ISP mode: 0, sensorId:0, Req(92)
04-10 16:41:09.551218 1478 9201 D MFNRCapability_Basic: (9201)[updateSelection] Mfll apply = 1, frames = 4// evaluateCaptureSetting 拍照决策 mainFrame:1 subFrames:3
//BSS output BSS 选帧
04-10 16:41:09.552314 1478 9201 D mtkcam-FeatureSettingPolicy: [evaluateCaptureSetting] capture request frames count(mainFrame:1, preCollectFrames:0, subFrames:3)
04-10 16:41:09.555439 1478 9201 D mtkcam-CaptureInFlightRequest: [insertRequest] insert capture RequestNo 92, size #:1
04-10 16:41:09.777355 1478 9373 D BssCore : (9373)[postPrepareRequests] MTK_FEATURE_BSS_PROCESS = 0, BSS output(enable bss:1) - order(0)
04-10 16:41:09.777365 1478 9373 D BssCore : (9373)[postPrepareRequests] MTK_FEATURE_BSS_PROCESS = 0, BSS output(enable bss:1) - order(3)
04-10 16:41:09.777373 1478 9373 D BssCore : (9373)[postPrepareRequests] MTK_FEATURE_BSS_PROCESS = 0, BSS output(enable bss:1) - order(1)
04-10 16:41:09.777379 1478 9373 D BssCore : (9373)[postPrepareRequests] MTK_FEATURE_BSS_PROCESS = 0, BSS output(enable bss:1) - order(2)// BSS: skip frame 过BSS 算法 skip的张数
04-10 16:41:09.778173 1478 9373 I MtkCam/CapturePipe/RootNode: [reorder]BSS: skip frame count: 0, golden:0// allocate memory 分配内存
04-10 16:41:09.820663 1478 9505 D MfllCore: {Mfll}[operator()] future allocate memory +// collected request(0/4) MFNR 收到帧的张数
04-10 16:41:09.821332 1478 9379 D MFNRPlugin: (9379)[process] collected request(0/4)
04-10 16:41:09.821347 1478 9508 D MfllCore: {Mfll}[operator()] times to blend(3), MEMC instanceNum(1), threadsNum(1)
04-10 16:41:09.821375 1478 9508 D MfllCore: {Mfll}[operator()] funcProcessMemc(0) +
04-10 16:41:09.841445 1478 9379 D MFNRPlugin: (9379)[process] collected request(1/4)
04-10 16:41:09.847348 1478 9505 D MfllCore: {Mfll}[operator()] future allocate memory -
04-10 16:41:09.863183 1478 9379 D MFNRPlugin: (9379)[process] collected request(2/4)
04-10 16:41:09.886023 1478 9379 D MFNRPlugin: (9379)[process] collected request(3/4)// memc 过完
04-10 16:41:09.913152 1478 9508 D MfllCore: {Mfll}[operator()] funcProcessMemc(0) -
04-10 16:41:09.913241 1478 9508 D MfllCore: {Mfll}[operator()] funcProcessMemc(1) +
04-10 16:41:09.920605 1478 9508 D MfllCore: {Mfll}[operator()] funcProcessMemc(1) -
04-10 16:41:09.920615 1478 9508 D MfllCore: {Mfll}[operator()] funcProcessMemc(2) +
04-10 16:41:09.927396 1478 9508 D MfllCore: {Mfll}[operator()] funcProcessMemc(2) -//doMsBlending 多帧融合
04-10 16:41:09.950564 1478 9510 D MfllCore: {Mfll}[doMsBlending] blending (0) ok
04-10 16:41:09.950575 1478 9510 D MfllCore: {Mfll}[doMsBlending] re-use input base buffer for 2nd blend
04-10 16:41:09.975629 1478 9510 D MfllCore: {Mfll}[doMsBlending] blending (1) ok
04-10 16:41:10.008877 1478 9510 D MfllCore: {Mfll}[doMsBlending] use working buffer as output
04-10 16:41:10.053627 1478 9510 D MfllCore: {Mfll}[doMsBlending] blending (2) ok
04-10 17:19:21.915968 13594 15334 D MfllCore: {Mfll}[doMsBlending] blending (4) ok// callback request 依次 callback 每一帧
04-10 16:41:10.053840 1478 9379 D MFNRPlugin: (9379)[process] callback request(0/4) 0xb4000079471651a8
04-10 16:41:10.054679 1478 9379 D MFNRPlugin: (9379)[process] callback request(1/4) 0xb4000079471651a8
04-10 16:41:10.055064 1478 9379 D MFNRPlugin: (9379)[process] callback request(2/4) 0xb4000079471651a8
04-10 16:41:10.055407 1478 9379 D MFNRPlugin: (9379)[process] callback request(3/4) 0xb4000079471651a8五 参考文献
MTK文档
参考文献：
【腾讯文档】Camera学习知识库
https://docs.qq.com/doc/DSWZ6dUlNemtUWndv
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