FPS帧率统计工具
时间:2025-02-19 09:54 来源:www.it.net.cn 作者:IT
从trace和录屏能算出大致帧率，更准确的帧率数据还需要从代码中统计
为了评估流畅度是否好，要计算1s 实际绘制的帧数，空闲不绘制的帧数，所以最好用2个帧率：
一个是满帧fps，一个是实际绘制fps，
好处是相比Surfaceflinger统计消费App生成的Buffer数量，可以从2个fps知道发现低于60帧，是真的掉帧了，还是没有绘制不是掉帧
如：doFrame ran 60 times (Real:34) 表示实际只绘制了34帧，但是可以绘制到60帧
实现原理：
在Choreographer的doFrame方法中加入一个计数器mFrameCount；当doFrame方法被调用时+1（mFrameCount++），启动1个Timer，1秒打印一个次logcat
每次doframe之后强制调用scheduleVsyncLocked()接受vsync，记录强制注册vsync的doFrame次数用变量mFrameMuteCount记录
但是统计不到Surfaceview（视频和地图），可以通过命令查看最近128帧内平均fps
dumpsys SurfaceFlinger --latency {layer_name}
输出结果：SurfaceView[renderframe]在最近128帧内平均fps: 29.88
使用方法：python fps.py com.map/com.map.MainActivity#0
dumpsys SurfaceFlinger --latency原理是：
https://cs.android.com/android/platform/superproject/+/master:frameworks/native/services/surfaceflinger/SurfaceFlinger.cpp
# prints some information about the last 128 frames displayed in # that window.The data returned looks like this: # 16954612 # 7657467895508 7657482691352 7657493499756 # (...) # # The first line is the refresh period of the HWC(vsync,here 16.95 ms)(e.g. 60hz->16.6ms 90hz->11.1ms) # 1st) app-vsync （fps.py get this value） # 2st) HWC-vsync # 3st) timestamp after SF submitted frame to the HWC # The difference between the 1st and 3rd timestamp is the frame-latency. # An interesting data is when the frame latency crosses a refresh period # boundary, this can be calculated this way: # # ceil((C - A) / refresh-period) # # (each time the number above changes, we have a "jank"). # If this happens a lot during an animation, the animation appears # janky, even if it runs at 60 fps in average void SurfaceFlinger::dumpStatsLocked(const DumpArgs& args, std::string& result) const { StringAppendF(&result, "%" PRId64 "\n", getVsyncPeriodFromHWC()); if (args.size() > 1) { const auto name = String8(args[1]); mCurrentState.traverseInZOrder([&](Layer* layer) { if (layer->getName() == name.string()) { layer->dumpFrameStats(result); } }); } else { mAnimFrameTracker.dumpStats(result); } }
其它统计方式：
window.addOnFrameMetricsAvailableListener 性能好，数据全，关键是找好接入时机
（官方推荐统计方式 https://zhuanlan.zhihu.com/p/619383056
adb shell dumpsys gfxinfo com.demo framestats 从应用生成的最近120个帧中输出带有纳秒时间戳的帧时间信息
(责任编辑：IT)
| 从trace和录屏能算出大致帧率，更准确的帧率数据还需要从代码中统计 为了评估流畅度是否好，要计算1s 实际绘制的帧数，空闲不绘制的帧数，所以最好用2个帧率： 一个是满帧fps，一个是实际绘制fps， 好处是相比Surfaceflinger统计消费App生成的Buffer数量，可以从2个fps知道发现低于60帧，是真的掉帧了，还是没有绘制不是掉帧 如：doFrame ran 60 times (Real:34) 表示实际只绘制了34帧，但是可以绘制到60帧 实现原理： 在Choreographer的doFrame方法中加入一个计数器mFrameCount；当doFrame方法被调用时+1（mFrameCount++），启动1个Timer，1秒打印一个次logcat 每次doframe之后强制调用scheduleVsyncLocked()接受vsync，记录强制注册vsync的doFrame次数用变量mFrameMuteCount记录 但是统计不到Surfaceview（视频和地图），可以通过命令查看最近128帧内平均fps dumpsys SurfaceFlinger --latency {layer_name} 输出结果：SurfaceView[renderframe]在最近128帧内平均fps: 29.88 使用方法：python fps.py com.map/com.map.MainActivity#0 dumpsys SurfaceFlinger --latency原理是： https://cs.android.com/android/platform/superproject/+/master:frameworks/native/services/surfaceflinger/SurfaceFlinger.cpp # prints some information about the last 128 frames displayed in # that window.The data returned looks like this: # 16954612 # 7657467895508 7657482691352 7657493499756 # (...) # # The first line is the refresh period of the HWC(vsync,here 16.95 ms)(e.g. 60hz->16.6ms 90hz->11.1ms) # 1st) app-vsync （fps.py get this value） # 2st) HWC-vsync # 3st) timestamp after SF submitted frame to the HWC # The difference between the 1st and 3rd timestamp is the frame-latency. # An interesting data is when the frame latency crosses a refresh period # boundary, this can be calculated this way: # # ceil((C - A) / refresh-period) # # (each time the number above changes, we have a "jank"). # If this happens a lot during an animation, the animation appears # janky, even if it runs at 60 fps in average void SurfaceFlinger::dumpStatsLocked(const DumpArgs& args, std::string& result) const { StringAppendF(&result, "%" PRId64 "\n", getVsyncPeriodFromHWC()); if (args.size() > 1) { const auto name = String8(args[1]); mCurrentState.traverseInZOrder([&](Layer* layer) { if (layer->getName() == name.string()) { layer->dumpFrameStats(result); } }); } else { mAnimFrameTracker.dumpStats(result); } } 其它统计方式： window.addOnFrameMetricsAvailableListener 性能好，数据全，关键是找好接入时机 （官方推荐统计方式 https://zhuanlan.zhihu.com/p/619383056 adb shell dumpsys gfxinfo com.demo framestats 从应用生成的最近120个帧中输出带有纳秒时间戳的帧时间信息 (责任编辑：IT) |