{"id":912,"date":"2026-06-17T15:45:52","date_gmt":"2026-06-17T15:45:52","guid":{"rendered":"https:\/\/boochlin.com\/?p=912"},"modified":"2026-09-16T09:53:40","modified_gmt":"2026-09-16T09:53:40","slug":"android-%e7%88%9b%e8%a3%9d%e7%bd%ae%e6%83%b3%e8%b7%91%e4%ba%ba%e8%87%89%e8%be%a8%e8%ad%986-gc-%e5%84%aa%e5%8c%96%e6%9c%80%e5%be%8c%e4%b8%80%e5%93%a9%e8%b7%af","status":"publish","type":"post","link":"https:\/\/boochlin.com\/?p=912","title":{"rendered":"Android \u721b\u88dd\u7f6e\u60f3\u8dd1\u4eba\u81c9\u8fa8\u8b586 \u2013 \u4e09\u8def\u9ad8\u983b\u5f71\u50cf\u6d41\u96f6\u62f7\u8c9d\uff1a\u55ae\u4e00\u53ef\u91cd\u7528 Bitmap \u9435\u7897\u8207 Zero-Allocation"},"content":{"rendered":"<p><img decoding=\"async\" src=\"..\/..\/assets\/images\/Android-%E8%A8%98%E6%86%B6%E9%AB%94%E8%AA%BF%E6%95%99.png\" alt=\"\"><\/p>\n<p>\u5728\u6211\u5011\u9019\u53f0\u639b\u5728\u7246\u4e0a\u7684\u58c1\u639b\u9580\u7981\u6a5f\u4e0a\uff0c\u540c\u6642\u63d2\u4e86\u5169\u9846\u786c\u9ad4\u93e1\u982d\uff1a<\/p>\n<ul>\n<li><strong>RGB \u53ef\u898b\u5149\u93e1\u982d<\/strong>\uff1a640&#215;480 YUV420 @ 30fps\uff08\u6bcf\u5e40 460.8 KB\uff0c\u541e\u5410\u91cf\u7d04 13.8 MB\/s\uff09\u3002<\/li>\n<li><strong>Sony IMX516 iToF \u6df1\u5ea6\u93e1\u982d<\/strong>\uff1a640&#215;1920 RAW12 @ 30fps\uff084 \u76f8\u4f4d Raw \u62fc\u63a5\uff0c\u6bcf\u5e40 1.84 MB\uff0c\u541e\u5410\u91cf\u9ad8\u9054 55.3 MB\/s\uff09\u3002<\/li>\n<\/ul>\n<p>\u7b97\u76e4\u4e00\u64a5\uff0c\u73fe\u5834\u6578\u64da\u4ee4\u4eba\u982d\u76ae\u767c\u9ebb\uff1a<\/p>\n<blockquote>\n<p>13.8 MB\/s (RGB) + 55.3 MB\/s (ToF RAW12) = 69.1 MB\/s<\/p>\n<\/blockquote>\n<p>\u5169\u9846\u93e1\u982d\u540c\u6642\u904b\u4f5c\uff0c\u5e95\u5c64\u6bcf\u79d2\u8981\u541e\u5410\u8d85\u904e 60 \u5e40\u5f71\u50cf\uff0c\u539f\u59cb\u6578\u64da\u704c\u5165\u901f\u5ea6\u63a5\u8fd1 <strong>\u6bcf\u79d2 70MB<\/strong>\u3002<\/p>\n<p>\u5982\u679c\u7167\u8457\u7db2\u8def\u4e0a\u5e38\u898b\u7684\u6559\u79d1\u66f8\u7bc4\u4f8b\u5beb\uff1a\u5728\u76f8\u6a5f\u56de\u8abf\u88e1\u628a YUV \u8f49\u6210 Bitmap\u3001\u6bcf\u4e00\u5e40 new \u4e00\u500b Data \u5bb9\u5668\u585e\u9032\u968a\u5217\u3001\u518d\u547c\u53eb\u6a21\u578b\u63a8\u8ad6\u2014\u2014<\/p>\n<blockquote>\n<p>69.1 MB\/s (\u76f8\u6a5f\u539f\u59cb\u5e40) + 36.8 MB\/s (RGB ARGB_8888 Bitmap) = 105.9 MB\/s<\/p>\n<\/blockquote>\n<p>\u6bcf\u79d2\u9418\u5f80\u8a18\u61b6\u9ad4\u88e1\u50be\u5012\u8d85\u904e 100MB \u7684\u7269\u4ef6\u5783\u573e\uff01\u5728\u6211\u5011\u9019\u53f0\u53ea\u6709 4 \u6838\u5fc3 1.3GHz \u5f31 CPU\u30012GB RAM \u7684\u7834\u677f\u5b50\u4e0a\uff0cJava Heap \u5728 1.5 \u79d2\u5167\u5c31\u6703\u88ab\u76f4\u63a5\u585e\u6eff\uff0c\u89f8\u767c\u983b\u7e41\u7684 Stop-The-World \u963b\u585e\u5f0f GC\uff0c\u756b\u9762\u77ac\u9593\u5361\u6b7b\u6210\u5e7b\u71c8\u7247\u3002<\/p>\n<p>\u9019\u662f\u4e00\u5834\u5728\u61f8\u5d16\u908a\u7de3\u7684\u6975\u9650\u62c9\u92f8\u6230\u3002\u8981\u8b93\u5f31\u96de\u786c\u9ad4\u7a69\u8dd1 30fps\uff0c\u6211\u5011\u52d5\u4e86\u4e94\u9053\u95dc\u9375\u7684\u5916\u79d1\u624b\u8853\u3002<\/p>\n<hr>\n<h2>\u624b\u8853\u4e00\uff1a\u767c\u653e\u9435\u7897\uff0c\u544a\u5225\u514d\u6d17\u9910\u5177\uff080-new \u9435\u5f8b\uff09<\/h2>\n<p>\u5728 30fps \u5f71\u50cf\u6d41\u4e0b\uff0c\u7559\u7d66\u6bcf\u4e00\u5e40\u7684\u8655\u7406\u6642\u9593\u9810\u7b97\u53ea\u6709\u6975\u5176\u56b4\u82db\u7684 <strong>33.3ms<\/strong>\u3002<\/p>\n<p>\u82e5\u6bcf\u5e40 new \u4e00\u500b 1.84MB \u7684 RAW \u9663\u5217\u52a0\u4e0a 1.22MB \u7684 Bitmap\uff0cJava \u5806\u7a4d\u6c34\u4f4d\u6bcf\u79d2\u66b4\u6f32\u3002\u6211\u5011\u7684\u539f\u5247\u6975\u5ea6\u51b7\u8840\uff1a<strong>\u5168\u7cfb\u7d71\u56b4\u7981\u4f7f\u7528\u514d\u6d17\u9910\u5177\uff0c\u6240\u6709\u4eba\u958b\u6a5f\u81ea\u5099\u9435\u7897\uff01<\/strong><\/p>\n<pre><code class=\"hljs language-java\"><span class=\"hljs-comment\">\/\/ CameraRgbHelper.java<\/span>\n<span class=\"hljs-keyword\">private<\/span> <span class=\"hljs-keyword\">static<\/span> <span class=\"hljs-keyword\">final<\/span> <span class=\"hljs-type\">int<\/span> <span class=\"hljs-variable\">YUV_QUEUE_MAX_SIZE<\/span> <span class=\"hljs-operator\">=<\/span> <span class=\"hljs-number\">3<\/span>;\n\n<span class=\"hljs-comment\">\/\/ \u958b\u6a5f\u53ea\u9810\u5148\u5206\u914d 3 \u500b\u56fa\u5b9a\u7684 byte[] \u9435\u7897\uff0c\u7d42\u751f\u4e0d\u92b7\u6bc0<\/span>\n<span class=\"hljs-keyword\">private<\/span> <span class=\"hljs-type\">ArrayBlockingQueue<\/span>&lt;<span class=\"hljs-type\">byte<\/span>[]&gt; <span class=\"hljs-variable\">mFreeYuvQueue<\/span> <span class=\"hljs-operator\">=<\/span> <span class=\"hljs-keyword\">new<\/span> <span class=\"hljs-title class_\">ArrayBlockingQueue<\/span>&lt;&gt;(YUV_QUEUE_MAX_SIZE);\n<span class=\"hljs-keyword\">private<\/span> <span class=\"hljs-type\">ArrayBlockingQueue<\/span>&lt;<span class=\"hljs-type\">byte<\/span>[]&gt; <span class=\"hljs-variable\">mYuvQueue<\/span> <span class=\"hljs-operator\">=<\/span> <span class=\"hljs-keyword\">new<\/span> <span class=\"hljs-title class_\">ArrayBlockingQueue<\/span>&lt;&gt;(YUV_QUEUE_MAX_SIZE);\n\n<span class=\"hljs-keyword\">private<\/span> <span class=\"hljs-keyword\">final<\/span> ImageReader.<span class=\"hljs-type\">OnImageAvailableListener<\/span> <span class=\"hljs-variable\">mOnImageAvailableListener<\/span> <span class=\"hljs-operator\">=<\/span> <span class=\"hljs-keyword\">new<\/span> <span class=\"hljs-title class_\">ImageReader<\/span>.OnImageAvailableListener() {\n    <span class=\"hljs-meta\">@Override<\/span>\n    <span class=\"hljs-keyword\">public<\/span> <span class=\"hljs-type\">void<\/span> <span class=\"hljs-title function_\">onImageAvailable<\/span><span class=\"hljs-params\">(ImageReader reader)<\/span> {\n        <span class=\"hljs-type\">Image<\/span> <span class=\"hljs-variable\">image<\/span> <span class=\"hljs-operator\">=<\/span> reader.acquireLatestImage();\n        <span class=\"hljs-keyword\">if<\/span> (image == <span class=\"hljs-literal\">null<\/span>) <span class=\"hljs-keyword\">return<\/span>;\n\n        <span class=\"hljs-keyword\">try<\/span> {\n            <span class=\"hljs-comment\">\/\/ \u5f9e\u6c60\u5b50\u501f\u51fa\u6d17\u4e7e\u6de8\u7684\u7a7a\u9592\u9435\u7897<\/span>\n            <span class=\"hljs-type\">byte<\/span>[] <span class=\"hljs-variable\">ironBowl<\/span> <span class=\"hljs-operator\">=<\/span> mFreeYuvQueue.poll();\n            <span class=\"hljs-keyword\">if<\/span> (ironBowl == <span class=\"hljs-literal\">null<\/span>) {\n                <span class=\"hljs-comment\">\/\/ \u968a\u5217\u6eff\u8f09\u6642\u7121\u60c5\u62cb\u68c4\u6700\u820a\u7684\u5e40\uff08Drop-Oldest\uff09\uff0c\u4fdd\u8b49 AI \u6c38\u9060\u53ea\u7b97\u6700\u65b0\u756b\u9762<\/span>\n                ironBowl = mYuvQueue.poll();\n            }\n\n            <span class=\"hljs-keyword\">if<\/span> (ironBowl != <span class=\"hljs-literal\">null<\/span>) {\n                <span class=\"hljs-comment\">\/\/ \u900f\u904e QFastCV \u9032\u884c ARM NEON \u5411\u91cf\u8a18\u61b6\u9ad4\u76f4\u62f7\uff08\u8017\u6642 &lt; 1ms\uff09<\/span>\n                QFastCV.yuv420SPToYuv420P(..., ironBowl, ...);\n                mYuvQueue.offer(ironBowl);\n            }\n        } <span class=\"hljs-keyword\">finally<\/span> {\n            <span class=\"hljs-comment\">\/\/ \u9748\u9b42\u95dc\u9375\uff1a\u5fc5\u9808\u5728 0.3ms \u5167\u6b78\u9084\u786c\u9ad4 Buffer\uff0c\u9632\u6b62 Camera HAL \u98e2\u9913\u6b7b\u9396\uff01<\/span>\n            image.close();\n        }\n    }\n};<\/code><\/pre>\n<p>\u76f8\u6a5f\u5e95\u5c64\u7684\u786c\u9ad4 Buffer \u53ea\u6709 2~3 \u500b\uff0c\u53ea\u8981\u4f60\u7684 Java \u57f7\u884c\u7dd2\u7a0d\u5fae\u5361\u9813\u6c92\u95dc\u9589\uff0c\u6574\u500b Camera HAL \u9a45\u52d5\u5c31\u6703\u7576\u5834\u6b7b\u9396\u3002\u6211\u5011\u5728 0.3ms \u5167\u628a\u6578\u64da\u5012\u9032\u9435\u7897\u4e26\u7acb\u523b <code>image.close()<\/code>\uff0c\u786c\u9ad4\u8cc7\u6e90\u79d2\u501f\u79d2\u9084\u3002<\/p>\n<hr>\n<h2>\u624b\u8853\u4e8c\uff1a\u7834\u9664 Bitmap \u8a5b\u5492\uff08\u55ae\u4e00\u53ef\u91cd\u7528 Bitmap \u9435\u7897\uff09<\/h2>\n<p>\u76f8\u6a5f\u5410\u51fa\u4f86\u7684\u662f YUV <code>byte[]<\/code>\uff0c\u4f46 AI SDK \u4ecb\u9762\u504f\u504f\u8981\u6c42\u50b3\u5165 <code>Bitmap<\/code>\u3002\u56e0\u70ba <code>copyPixelsFromBuffer<\/code> \u53ea\u505a\u7d14\u7cb9\u7684\u8a18\u61b6\u9ad4\u62f7\u8c9d\uff0c\u4e0d\u5305\u542b\u8272\u5f69\u7a7a\u9593\u8f49\u63db\uff0c\u6240\u4ee5\u6211\u5011\u5fc5\u9808\u5148\u5c07 YUV \u8f49\u63db\u70ba ARGB\u3002\u5982\u679c\u6bcf\u5e40\u547c\u53eb <code>Bitmap.createBitmap()<\/code> \u6216 <code>bitmap.copy()<\/code>\uff0c\u6bcf\u79d2\u6703\u984d\u5916\u7522\u751f 36MB \u7684 Bitmap \u5783\u573e\u3002<\/p>\n<p>\u6211\u5011\u5728\u958b\u6a5f\u6642<strong>\u53ea new \u4e00\u5f35\u56fa\u5b9a\u7684 Bitmap \u9435\u7897<\/strong>\uff0c\u4e26\u9810\u5148\u5206\u914d\u4e00\u584a DirectBuffer\u3002\u63a8\u8ad6\u6642\u5148\u900f\u904e Native \u5eab\u5b8c\u6210\u5fc5\u8981\u7684 YUV \u5230 ARGB \u8f49\u63db\uff0c\u518d\u5c07\u5e95\u5c64\u8a18\u61b6\u9ad4\u76f4\u63a5\u8986\u5beb\u9032 Bitmap \u50cf\u7d20\uff0c\u9054\u6210 0 \u5206\u914d\uff1a<\/p>\n<pre><code class=\"hljs language-java\"><span class=\"hljs-comment\">\/\/ \u958b\u6a5f\u53ea new \u4e00\u6b21 Bitmap \u9435\u7897\u8207 Native \u7de9\u885d\u5340<\/span>\n<span class=\"hljs-type\">Bitmap<\/span> <span class=\"hljs-variable\">reusableBitmap<\/span> <span class=\"hljs-operator\">=<\/span> Bitmap.createBitmap(<span class=\"hljs-number\">640<\/span>, <span class=\"hljs-number\">480<\/span>, Bitmap.Config.ARGB_8888);\n<span class=\"hljs-type\">ByteBuffer<\/span> <span class=\"hljs-variable\">argbBuffer<\/span> <span class=\"hljs-operator\">=<\/span> ByteBuffer.allocateDirect(<span class=\"hljs-number\">640<\/span> * <span class=\"hljs-number\">480<\/span> * <span class=\"hljs-number\">4<\/span>);\n\n<span class=\"hljs-keyword\">public<\/span> <span class=\"hljs-type\">void<\/span> <span class=\"hljs-title function_\">processFrame<\/span><span class=\"hljs-params\">(<span class=\"hljs-type\">byte<\/span>[] ironBowlBytes)<\/span> {\n    argbBuffer.rewind();\n\n    <span class=\"hljs-comment\">\/\/ \u5fc5\u9808\u7684\u8272\u5f69\u8f49\u63db\u6b65\u9a5f\uff1a\u900f\u904e LibYUV \u5728 Native \u7aef\u5c07 YUV \u8f49\u70ba ARGB \u4e26\u5beb\u5165 argbBuffer\uff08\u6975\u901f\u30010 GC\uff09<\/span>\n    NativeYuvUtils.yuv420ToArgb(ironBowlBytes, <span class=\"hljs-number\">640<\/span>, <span class=\"hljs-number\">480<\/span>, argbBuffer);\n    \n    argbBuffer.rewind();\n\n    <span class=\"hljs-comment\">\/\/ \u5c07\u5df2\u8f49\u63db\u7684 ARGB \u6578\u64da\u76f4\u63a5 memcpy \u5237\u5165\u65e2\u6709 Bitmap \u7684 Native \u8a18\u61b6\u9ad4\u4f4d\u5740\uff080 \u8a18\u61b6\u9ad4\u5206\u914d\uff09<\/span>\n    reusableBitmap.copyPixelsFromBuffer(argbBuffer);\n\n    <span class=\"hljs-comment\">\/\/ \u9935\u7d66\u4eba\u81c9\u5075\u6e2c\u6a21\u578b<\/span>\n    Face3DAIModelKit.start().runRgbFD(reusableBitmap, <span class=\"hljs-number\">140<\/span>, <span class=\"hljs-number\">140<\/span>);\n}<\/code><\/pre>\n<p>\u6574\u53f0\u8a2d\u5099\u5728\u63a8\u8ad6\u5faa\u74b0\u4e2d\u53ea\u6709\u4e00\u5f35 Bitmap \u5be6\u9ad4\uff0c\u900f\u904e Native \u8f49\u63db\u8207\u8a18\u61b6\u9ad4\u76f4\u704c\uff0c\u5fb9\u5e95\u6d88\u6ec5 GC \u58d3\u529b\u3002<\/p>\n<h3>\u9435\u7897\u5e36\u4f86\u7684\u786c\u9ad4\u7d1a\u56de\u5831\uff1aQM215 \u5be6\u6e2c\u57fa\u6e96\u6578\u64da<\/h3>\n<p>\u9019\u4e0d\u662f\u7406\u8ad6\u81ea\u55e8\u3002\u5728\u6211\u5011\u9019\u584a 2GB RAM \/ Android 9 \u7684\u9ad8\u901a QM215 \u9580\u7981\u677f\u4e0a\uff0cSystrace \u8207 dumpsys \u8a18\u9304\u4e86\u6700\u771f\u5be6\u7684\u786c\u9ad4\u9707\u64bc\uff1a<\/p>\n<table>\n<thead>\n<tr>\n<th align=\"left\">\u7cfb\u7d71\u76e3\u63a7\u6307\u6a19 (dumpsys \/ top)<\/th>\n<th align=\"left\">\u512a\u5316\u524d (\u6bcf\u5e40 new Bitmap \u514d\u6d17\u9910\u5177)<\/th>\n<th align=\"left\">\u512a\u5316\u5f8c (\u55ae\u4e00 Bitmap \u9435\u7897\u6a5f\u5236)<\/th>\n<th align=\"left\">\u5be6\u6230\u67b6\u69cb\u6536\u76ca<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td align=\"left\"><strong>Java \u5806\u5206\u914d\u901f\u7387<\/strong><\/td>\n<td align=\"left\"><strong>45 ~ 55 MB\/s<\/strong><\/td>\n<td align=\"left\"><strong>0 bytes\/s (\u7a69\u614b\u96f6\u65b0\u589e)<\/strong><\/td>\n<td align=\"left\">\u5fb9\u5e95\u6d88\u6ec5\u77ed\u547d\u5927\u7269\u4ef6\uff08LOS\uff09<\/td>\n<\/tr>\n<tr>\n<td align=\"left\"><strong>GC \u983b\u7387\u8207\u985e\u578b<\/strong><\/td>\n<td align=\"left\">\u6bcf\u79d2 <strong>2 ~ 3 \u6b21<\/strong> <code>GC_FOR_ALLOC<\/code><\/td>\n<td align=\"left\"><strong>0 \u6b21 \/ \u5c0f\u6642<\/strong>\uff08\u7a69\u614b\u96f6 GC\uff09<\/td>\n<td align=\"left\">\u6d88\u9664 JVM \u5167\u90e8\u8cc7\u6e90\u722d\u596a<\/td>\n<\/tr>\n<tr>\n<td align=\"left\"><strong>STW \u505c\u9813\u6642\u9593<\/strong><\/td>\n<td align=\"left\">\u6bcf\u6b21 <strong>15 ~ 35 ms<\/strong>\uff08\u756b\u9762\u51cd\u7d50\uff09<\/td>\n<td align=\"left\"><strong>0 ms<\/strong><\/td>\n<td align=\"left\">\u5fb9\u5e95\u675c\u7d55 UI \u8207\u76f8\u6a5f\u7ba1\u7dda\u5361\u6b7b<\/td>\n<\/tr>\n<tr>\n<td align=\"left\"><strong>Linux \u5167\u6838 <code>kswapd0<\/code> \u4f54\u7528<\/strong><\/td>\n<td align=\"left\"><strong>45% ~ 60%<\/strong>\uff08\u760b\u72c2\u58d3\u7e2e\u5206\u9801\u81f3 ZRAM\uff09<\/td>\n<td align=\"left\"><strong>&lt; 2%<\/strong>\uff08\u5167\u6838\u6975\u5ea6\u5e73\u7a69\uff09<\/td>\n<td align=\"left\"><strong>\u596a\u56de 50%+ \u5be6\u9ad4 CPU \u7b97\u529b<\/strong><\/td>\n<\/tr>\n<tr>\n<td align=\"left\"><strong>\u76f8\u6a5f\u9810\u89bd\u6389\u5e40\u7387<\/strong><\/td>\n<td align=\"left\"><strong>35% ~ 42%<\/strong>\uff0830fps \u66b4\u8dcc\u81f3 18fps\uff09<\/td>\n<td align=\"left\"><strong>&lt; 0.1% (\u7a69\u8dd1 30.0 fps)<\/strong><\/td>\n<td align=\"left\">\u9054\u6210 720h \u4e0d\u505c\u6a5f\u901a\u884c<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>\u56b4\u8b39\u6b63\u540d\uff1aZero-Allocation vs. \u771f\u6b63\u6676\u7247\u7d1a Zero-Copy<\/h3>\n<p>\u56b4\u683c\u4f86\u8aaa\uff0c<code>reusableBitmap.copyPixelsFromBuffer(argbBuffer)<\/code> \u5e95\u5c64\u5728 Skia \u4ecd\u6703\u57f7\u884c\u4e00\u6b21 CPU <code>memcpy<\/code>\u3002\u5728\u5e95\u5c64\u591a\u5a92\u9ad4\u5de5\u7a0b\u5e2b\u773c\u88e1\uff0c\u9019\u4e0d\u53eb\u771f\u6b63\u7684\u6676\u7247\u7d1a\u96f6\u62f7\u8c9d\uff08\u771f\u6b63\u96f6\u62f7\u8c9d\u8d70\u7684\u662f\u76f8\u6a5f ISP \u76f4\u63a5\u8f38\u51fa DMA-BUF \/ ION \u5171\u4eab\u8a18\u61b6\u9ad4\uff0cGPU \u76f4\u63a5\u8cbc\u5716\u6e32\u67d3\uff0cCPU \u78b0\u90fd\u4e0d\u78b0\uff09\u3002<\/p>\n<p>\u4f46\u9019\u5957\u65b9\u6848\u5728\u5de5\u7a0b\u5be6\u52d9\u4e0a\u89e3\u6c7a\u4e86\u6700\u81f4\u547d\u7684\u75db\u9ede\uff1a<strong>\u5b83\u5be6\u73fe\u4e86\u61c9\u7528\u5c64\u7684\u300cZero-Allocation\uff08\u96f6\u8a18\u61b6\u9ad4\u5206\u914d\uff09\u300d<\/strong>\u3002\u53d7\u5236\u65bc\u7b2c\u4e09\u65b9\u9589\u6e90 AI SDK \u63a5\u53e3\u5beb\u6b7b\u53ea\u5403 <code>Bitmap<\/code> \u7684\u7121\u5948\u73fe\u5be6\u4e0b\uff0c\u9435\u7897\u662f\u552f\u4e00\u80fd\u65ac\u65b7 GC \u6d77\u562f\u3001\u5c07 50% CPU \u7b97\u529b\u596a\u56de\u7d66 AI \u7684\u6700\u512a\u89e3\uff01<\/p>\n<hr>\n<h2>\u624b\u8853\u4e09\uff1a\u7121\u60c5\u7684 Drop-Oldest\uff08\u96d9\u5c64\u80cc\u58d3\u6a5f\u5236\uff09<\/h2>\n<p>\u76f8\u6a5f\u6bcf\u79d2\u786c\u751f\u751f\u585e\u9032 30 \u5e40\uff0c\u4f46\u5728 1.3GHz \u7684\u5f31 CPU \u4e0a\uff0c\u8dd1\u5b8c\u5b8c\u6574\u7684 512 \u7dad\u7279\u5fb5\u8403\u53d6\u4e00\u79d2\u9802\u591a\u7b97 5~6 \u5e40\u3002<\/p>\n<p>\u7b97\u5f0f\u544a\u8a34\u6211\u5011\uff0c\u5169\u8005\u4e4b\u9593\u5b58\u5728\u8457\u5de8\u5927\u7684\u901f\u7387\u5dee\uff1a<\/p>\n<blockquote>\n<p>30 fps (\u76f8\u6a5f\u4f9b\u7d66) vs 6 fps (AI \u6d88\u5316\u6975\u9650) = \u6bcf\u79d2\u7a4d\u58d3 24 \u5e40\uff01<\/p>\n<\/blockquote>\n<p>\u5982\u679c\u4e0d\u505a\u80cc\u58d3\u63a7\u5236\uff0c\u968a\u5217\u6703\u5728\u5e7e\u79d2\u5167\u88ab\u704c\u7206\u3002\u6211\u5011\u8a2d\u8a08\u4e86<strong>\u96d9\u5c64\u80cc\u58d3\u4e1f\u5305\u7b56\u7565<\/strong>\uff1a<\/p>\n<ol>\n<li><strong>\u786c\u9ad4\u5c64<\/strong>\uff1a\u4e00\u5f8b\u547c\u53eb <code>acquireLatestImage()<\/code>\u3002\u76f8\u6a5f\u5e95\u5c64\u82e5\u7a4d\u58d3\u591a\u5e40\uff0c\u53ea\u53d6\u6700\u65b0\u4e00\u5e40\uff0c\u904e\u671f\u7684\u6b98\u5f71\u5728\u9a45\u52d5\u5c64\u76f4\u63a5\u4e1f\u68c4\u3002<\/li>\n<li><strong>\u8edf\u9ad4\u5c64<\/strong>\uff1a\u968a\u5217\u4e0a\u9650\u9396\u6b7b\u70ba 3\uff08<code>YUV_QUEUE_MAX_SIZE = 3<\/code>\uff09\u3002\u968a\u5217\u4e00\u6eff\uff0c\u76f4\u63a5\u8e22\u6389\u6700\u820a\u7684\u5e40\uff0c\u628a\u9435\u7897\u6b78\u9084\u7a7a\u9592\u6c60\u3002<\/li>\n<\/ol>\n<p>\u9580\u7981\u6a5f\u6c38\u9060\u53ea\u63a8\u8ad6\u300c\u7576\u4e0b\u6700\u65b0\u7684\u4e00\u5f35\u81c9\u300d\uff0c\u7d55\u4e0d\u6d6a\u8cbb\u534a\u9ede\u7b97\u529b\u53bb\u7b97\u904e\u671f\u4e86\u5e7e\u767e\u6beb\u79d2\u7684\u6b77\u53f2\u6b98\u5f71\u3002<\/p>\n<hr>\n<h2>\u624b\u8853\u56db\uff1a\u968e\u68af\u5f0f\u6f0f\u6597\u6dd8\u6c70\uff08\u56db\u5927\u60e1\u9738\u77ed\u8def\u9000\u5834\uff09<\/h2>\n<p>CNN 512 \u7dad\u7279\u5fb5\u8403\u53d6\uff08MobileFaceNet\uff09\u5728 1.3GHz CPU \u4e0a\u8dd1\u4e00\u6b21\u8981\u8017\u8cbb 180ms ~ 220ms\u3002\u5982\u679c\u4e0d\u7ba1\u756b\u9762\u6709\u6c92\u6709\u4eba\u3001\u6e05\u4e0d\u6e05\u695a\u90fd\u8dd1\u5b8c\u6574\u6a21\u578b\uff0c4 \u9846 CPU \u6838\u5fc3\u4fdd\u8b49 100% \u6eff\u8f09\u904e\u71b1\uff0c\u9032\u800c\u89f8\u767c\u6676\u7247\u964d\u983b\u3002<\/p>\n<p>\u6211\u5011\u5efa\u7acb\u4e86\u968e\u68af\u5f0f\u6f0f\u6597\u904e\u6ffe\uff0c\u4f9d\u8a08\u7b97\u6210\u672c\u7531\u4f4e\u5230\u9ad8\u9010\u7d1a\u65ac\u6bba\uff1a<\/p>\n<pre><code class=\"hljs language-plaintext\">[\u76f8\u6a5f\u8f38\u5165 (30fps)]\n       \u2502\n       \u25bc \u7b2c 0 \u95dc\uff1a\u96d9\u93e1\u982d\u6642\u9593\u6233\u540c\u6b65\u6aa2\u67e5 (&lt; 0.1ms) \u2500\u2500\u2500\u25ba \u672a\u540c\u6b65\uff1f\u4e1f\u68c4\uff01\n       \u2502\n       \u25bc \u7b2c 1 \u95dc\uff1aRGB \u4eba\u81c9\u5075\u6e2c FD (~5ms) \u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u25ba \u6c92\u81c9\uff1f\u7acb\u5373\u77ed\u8def\u9000\u51fa\uff01\n       \u2502\n       \u25bc \u7b2c 2 \u95dc\uff1a\u6e05\u6670\u5ea6\u8207\u59ff\u614b\u904e\u6ffe FQ (~1ms) \u2500\u2500\u2500\u2500\u2500\u2500\u25ba \u6a21\u7cca \/ \u5074\u81c9\uff1f\u4e1f\u68c4\uff01\n       \u2502\n       \u25bc \u7b2c 3 \u95dc\uff1aIR + 3D \u6df1\u5ea6\u96d9\u6a21\u614b\u6d3b\u9ad4 (~15ms) \u2500\u2500\u25ba \u5047\u4eba \/ \u7167\u7247\uff1f\u76f4\u63a5\u5831\u8b66\uff01\n       \u2502\n       \u25bc \u7b2c 4 \u95dc\uff1a512 \u7dad CNN \u7279\u5fb5\u8403\u53d6 FR (~200ms)\n[\u6bd4\u5c0d\u672c\u5730 5000 \u4eba\u7279\u5fb5\u5eab (ACL \u77e9\u9663\u641c\u5c0b ~3ms)]<\/code><\/pre>\n<h3>\u70ba\u4ec0\u9ebc\u9019\u80fd\u62ef\u6551\u7834\u786c\u9ad4\uff1f<\/h3>\n<ul>\n<li><strong>\u5927\u9580\u53e3 90% \u7684\u6642\u9593\u662f\u6c92\u4eba\u7684<\/strong>\uff1a\u7b2c 1 \u95dc\uff08FD\uff09\u5728 5ms \u5167\u78ba\u8a8d\u6c92\u81c9\uff0c\u76f4\u63a5 <code>return false<\/code> \u77ed\u8def\u9000\u5834\uff0c\u7701\u4e0b\u5f8c\u7e8c 99% \u7684\u7121\u8b02\u904b\u7b97\u3002<\/li>\n<li>\u53ea\u6709\u7576\u4e00\u500b\u5927\u6d3b\u4eba\u7aef\u7aef\u6b63\u6b63\u7ad9\u5728\u93e1\u982d\u524d\u3001\u4e14\u901a\u904e\u4e86\u6e05\u6670\u5ea6\u8207\u96d9\u6a21\u614b\u6d3b\u9ad4\u9632\u507d\uff0c\u7cfb\u7d71\u624d\u6703\u8abf\u7528\u8017\u6642 200ms \u7684 CNN \u6838\u5fc3\u6a21\u578b\u3002<\/li>\n<li>\u5f85\u6a5f\u6642\u5e73\u5747 CPU \u8ca0\u8f09\u76f4\u63a5\u5f9e 100% \u58d3\u5236\u5230 15%~20%\uff0c\u5fb9\u5e95\u89e3\u6c7a\u5bc6\u9589\u6a5f\u6bbc\u5167\u7684\u904e\u71b1\u964d\u983b\u554f\u984c\u3002<\/li>\n<\/ul>\n<hr>\n<h2>\u624b\u8853\u4e94\uff1a\u907f\u958b Java \u8f49\u63db\u7684 GC \u70b8\u5f48\uff08QFastCV \u539f\u751f\u76f4\u8f49\uff09<\/h2>\n<p>\u4f7f\u7528 Android \u5b98\u65b9\u7684 <code>YuvImage.compressToJpeg()<\/code> \u6703\u88fd\u9020 3 \u500b\u5927\u578b\u66ab\u5b58 byte \u9663\u5217\u8207\u6602\u8cb4\u7684 JPEG \u7de8\u89e3\u78bc\u958b\u92b7\uff0c\u4e00\u6b21\u8f49\u63db\u8017\u6642 40ms\u3002<\/p>\n<p>\u6211\u5011\u5728 <code>CameraRgbHelper<\/code> \u4e2d\u76f4\u63a5\u8abf\u7528\u9ad8\u901a <strong>QFastCV<\/strong> \u539f\u751f\u5eab\uff1a<\/p>\n<pre><code class=\"hljs language-java\"><span class=\"hljs-comment\">\/\/ \u900f\u904e ARM NEON \u5411\u91cf\u6307\u4ee4\u5728 Native C++ \u5b8c\u6210 YUV \u683c\u5f0f\u8f49\u63db<\/span>\nQFastCV.yuv420SPToYuv420P(\n    bufferY, bufferU, \n    CAM_RGB_WIDTH, CAM_RGB_HEIGHT,\n    stride0, stride1,\n    dstY, dstU, dstV,\n    <span class=\"hljs-number\">0<\/span>, <span class=\"hljs-number\">0<\/span>, <span class=\"hljs-number\">0<\/span>\n);<\/code><\/pre>\n<p>\u8f49\u63db\u5728 C++ \u5c64\u4ee5 SIMD \u6307\u4ee4\u4e26\u884c\u904b\u7b97\uff0c\u8017\u6642\u4e0d\u5230 1ms\uff0cJava \u5806\u7a4d 0 \u5783\u573e\u3002<\/p>\n<hr>\n<h2>\u7d50\u8a9e\u8207\u9632\u5751\u5fc3\u6cd5<\/h2>\n<p>\u5728\u4f4e\u914d\u5d4c\u5165\u5f0f\u8a2d\u5099\u4e0a\u641e\u908a\u7de3 AI\uff0c\u786c\u9ad4\u4e0d\u6703\u540c\u60c5\u4f60\uff1a<\/p>\n<ol>\n<li><strong>\u9435\u7897\u5faa\u74b0\u662f\u57fa\u77f3<\/strong>\uff1a\u5168\u7cfb\u7d71 0-new\uff0c\u7528\u56fa\u5b9a\u7684\u7de9\u885d\u6c60\u65ac\u65b7 GC \u7684\u89f8\u624b\u3002<\/li>\n<li><strong>\u80cc\u58d3\u4e1f\u5305\u8981\u5fc3\u72e0\u624b\u8fa3<\/strong>\uff1a\u6c38\u9060\u53ea\u63a8\u8ad6\u7576\u4e0b\u6700\u65b0\u7684\u5e40\uff0c\u904e\u671f\u5e40\u6c92\u6709\u4efb\u4f55\u7559\u6200\u50f9\u503c\u3002<\/li>\n<li><strong>\u968e\u68af\u6f0f\u6597\u7701\u7b97\u529b<\/strong>\uff1a\u4f4e\u6210\u672c\u7b97\u6cd5\u5728\u524d\u9762\u628a\u95dc\uff0c\u9ad8\u6210\u672c\u6a21\u578b\u5728\u6700\u5f8c\u6536\u5c3e\u3002<\/li>\n<li><strong>\u8a18\u61b6\u9ad4\u62bd\u8102\u6230\u679c<\/strong>\uff1a\u6b77\u7d93\u9435\u7897\u5faa\u74b0\u3001Native \u8986\u5beb\u8207 DirectBuffer \u96f6\u62f7\u8c9d\u9019\u4e94\u5927\u624b\u8853\uff0cJava \u5c64\u7269\u4ef6\u6c60\u91cd\u7528\u6a5f\u5236\u5927\u5e45\u58d3\u4f4e\u4e86 Dalvik Heap \u7684\u5cf0\u503c\u4f54\u7528\u8207 GC \u983b\u7387\uff0c\u642d\u914d\u76f8\u6a5f\u89e3\u6790\u5ea6\u964d\u7d1a\u8207 Stream \u6578\u91cf\u7cbe\u7c21\uff0c\u5728\u7cfb\u7d71\u5c64\u9762\u70ba AI \u6a21\u578b\u91cb\u653e\u4e86\u53ef\u89c0\u7684\u5be6\u9ad4\u8a18\u61b6\u9ad4\u7a7a\u9593\u3002<\/li>\n<\/ol>\n<p>\u4e0b\u4e00\u7bc7\uff0c\u6211\u5011\u628a\u8996\u89d2\u62c9\u5230\u771f\u5be6\u7269\u7406\u4e16\u754c\uff1a<strong>\u7576\u9580\u7981\u6a5f\u906d\u9047\u7db2\u5361\u6b7b\u9396\u3001\u76f8\u6a5f\u65b7\u6d41\u8207\u534a\u591c\u7576\u6a5f\u6642\uff0c\u5982\u4f55\u7528\u4e00\u5957\u8edf\u786c\u9ad4 Watchdog \u5be6\u73fe\u7269\u7406\u7d1a\u4e0d\u6b7b\u4e4b\u8eab\uff01<\/strong><\/p>\n<hr>\n<h2>\u53c3\u8003\u8cc7\u6599 (References)<\/h2>\n<ol>\n<li>\n<p><strong>Android Camera2 API Best Practices: Avoiding HAL Starvation<\/strong>.<br \/>\n<a href=\"https:\/\/developer.android.com\/training\/camera2\">https:\/\/developer.android.com\/training\/camera2<\/a><\/p>\n<\/li>\n<li>\n<p><strong>Android Graphics Bitmap Native Allocation &amp; In-place Buffers<\/strong>.<br \/>\n<a href=\"https:\/\/source.android.com\/docs\/core\/graphics\">https:\/\/source.android.com\/docs\/core\/graphics<\/a><\/p>\n<\/li>\n<li>\n<p><strong>Qualcomm FastCV Computer Vision SDK Overview<\/strong>.<br \/>\n<a href=\"https:\/\/developer.qualcomm.com\/software\/fastcv-sdk\">https:\/\/developer.qualcomm.com\/software\/fastcv-sdk<\/a><\/p>\n<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"<p>\u5728 Android \u8655\u7406\u76f8\u6a5f\u4e32\u6d41\uff0c\u76f8\u6a5f\u6bcf\u79d2\u5410\u51fa\u4f86\u7684\u5f71\u50cf\u8cc7\u6599\u8ddf\u5c71\u4e00\u6a23\u5927\u3002<\/p>\n<p>\u5982\u679c\u4f60\u6bcf\u4e00\u5f35\u5716\u90fd\u53bb\u00a0new\u00a0\u4e00\u500b\u65b0\u7a7a\u9593\uff08\u5c31\u50cf\u4f7f\u7528\u514d\u6d17\u9910\u5177\uff09\uff0c\u7528\u5b8c\u5c31\u4e1f\u7d66\u7cfb\u7d71\u56de\u6536\uff0c\u7cfb\u7d71\u5149\u662f\u300c\u8ddf\u5728\u5f8c\u9762\u64bf\u5783\u573e (GC)\u300d\u5c31\u6703\u5361\u5230\u61f7\u7591\u4eba\u751f\uff1a\u4e0a\u4e00\u79d2\u958b\u9580\u5f88\u9806\uff0c\u4e0b\u4e00\u79d2\u64bf\u500b\u5783\u573e\u5c31\u5361\u4e86 800ms\u3002\u6700\u5f8c\u7cfb\u7d71\u6703\u76f4\u63a5\u56e0\u70ba\u5783\u573e\u5806\u6eff (OOM) \u800c\u9583\u9000\u3002<\/p>\n","protected":false},"author":1,"featured_media":1242,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[166],"tags":[195,214,287,115],"_links":{"self":[{"href":"https:\/\/boochlin.com\/index.php?rest_route=\/wp\/v2\/posts\/912"}],"collection":[{"href":"https:\/\/boochlin.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/boochlin.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/boochlin.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/boochlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=912"}],"version-history":[{"count":16,"href":"https:\/\/boochlin.com\/index.php?rest_route=\/wp\/v2\/posts\/912\/revisions"}],"predecessor-version":[{"id":1366,"href":"https:\/\/boochlin.com\/index.php?rest_route=\/wp\/v2\/posts\/912\/revisions\/1366"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/boochlin.com\/index.php?rest_route=\/wp\/v2\/media\/1242"}],"wp:attachment":[{"href":"https:\/\/boochlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=912"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/boochlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=912"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/boochlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=912"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}