【UVCcamera/新手向】AS中初次使用OpenCV

• 
  

  简单的灰度图

  

   o0olele/UVCcamera-OpenCV

  1.  新建一个camera的工程

  2.  将第三方库文件（源码里有）复制到对应位置

  

  3.  更改项目下的build.gradle

  4.  更改app下的build.gradle

  5.  更改界面，添加camera_view(这是UVC要求的，貌似)、imageView(用于显示opencv处理后的图像)、一个button(普通、imagebutton都行)

  

  6.  源代码

  （部分注释，刚入门，自己的一些理解）

  说在前面

• 过程 

• 源码地址

• 运行截图

• 说在前面

1. package com.example.o0orick.camera;
3. import android.animation.Animator;
4. import android.graphics.Bitmap;
5. import android.graphics.Matrix;
6. import android.graphics.SurfaceTexture;
7. import android.hardware.usb.UsbDevice;
8. import android.os.Bundle;
9. import android.support.annotation.NonNull;
10. import android.util.Log;
11. import android.view.Surface;
12. import android.view.View;
13. import android.view.View.OnClickListener;
14. import android.view.Window;
15. import android.view.WindowManager;
16. import android.widget.AdapterView;
17. import android.widget.CompoundButton;
18. import android.widget.ImageButton;
19. import android.widget.ImageView;
20. import android.widget.SeekBar;
21. import android.widget.Spinner;
22. import android.widget.TextView;
23. import android.widget.Toast;
24. import android.widget.ToggleButton;
26. import com.serenegiant.common.BaseActivity;
27. import com.serenegiant.usb.CameraDialog;
28. import com.serenegiant.usb.IFrameCallback;
29. import com.serenegiant.usb.USBMonitor;
30. import com.serenegiant.usb.USBMonitor.OnDeviceConnectListener;
31. import com.serenegiant.usb.USBMonitor.UsbControlBlock;
32. import com.serenegiant.usb.UVCCamera;
33. import com.serenegiant.usbcameracommon.UVCCameraHandler;
34. import com.serenegiant.utils.ViewAnimationHelper;
35. import com.serenegiant.widget.CameraViewInterface;
37. import org.opencv.android.BaseLoaderCallback;
38. import org.opencv.android.LoaderCallbackInterface;
39. import org.opencv.android.OpenCVLoader;
40. import org.opencv.android.Utils;
41. import org.opencv.core.Mat;
42. import org.opencv.core.MatOfPoint;
43. import org.opencv.core.MatOfRect;
44. import org.opencv.core.Rect;
45. import org.opencv.imgproc.Imgproc;
47. import java.math.BigDecimal;
48. import java.nio.ByteBuffer;
49. import java.util.ArrayList;
50. import java.util.List;
52. public final class MainActivity extends BaseActivity implements CameraDialog.CameraDialogParent {
53. private static final boolean DEBUG = true; // TODO set false on release
54. private static final String TAG = "MainActivity";
56. /**
57. * 操作锁
58. */
59. private final Object mSync = new Object();
61. /**
62. * set true if you want to record movie using MediaSurfaceEncoder
63. * (writing frame data into Surface camera from MediaCodec
64. * by almost same way as USBCameratest2)
65. * set false if you want to record movie using MediaVideoEncoder
66. */
67. private static final boolean USE_SURFACE_ENCODER = false;
69. /**
70. * preview resolution(width)
71. * if your camera does not support specific resolution and mode,
72. * {@link UVCCamera#setPreviewSize(int, int, int)} throw exception
73. */
74. private static final int PREVIEW_WIDTH = 640; // 640
75. /**
76. * preview resolution(height)
77. * if your camera does not support specific resolution and mode,
78. * {@link UVCCamera#setPreviewSize(int, int, int)} throw exception
79. */
80. private static final int PREVIEW_HEIGHT = 480; //480
81. /**
82. * preview mode
83. * if your camera does not support specific resolution and mode,
84. * {@link UVCCamera#setPreviewSize(int, int, int)} throw exception
85. * 0:YUYV, other:MJPEG
86. */
87. private static final int PREVIEW_MODE = 0; // YUV
89. protected static final int SETTINGS_HIDE_DELAY_MS = 2500;
91. /**
92. * for accessing USB
93. */
94. private USBMonitor mUSBMonitor;
95. /**
96. * Handler to execute camera related methods sequentially on private thread
97. */
98. private UVCCameraHandler mCameraHandler;
99. /**
100. * for camera preview display
101. */
102. private CameraViewInterface mUVCCameraView;
103. /**
104. * for open&start / stop&close camera preview
105. */
106. private ImageButton mCameraButton;
107. private ImageView mImageView;
108. private boolean isScaling = false;
109. private boolean isInCapturing = false;
111. private int[][] capture_solution = {{640,480}, {800,600},{1024,768}, {1280,1024}};
112. private int mCaptureWidth = capture_solution[0][0];
113. private int mCaptureHeight = capture_solution[0][1];
115. /**
116. * opencv的一个抽象类，为了支持opencv与app之间的相互作用，
117. * 该类声明了一个callback，在opencv manager之后执行，这个回调是为了使opencv在合适的地方进行初始化
118. */
119. private BaseLoaderCallback mLoaderCallback = new BaseLoaderCallback(this) {
120. @Override
121. public void onManagerConnected(int status) {
122. switch (status) {
123. case LoaderCallbackInterface.SUCCESS:
124. {
125. Log.i(TAG, "OpenCV loaded successfully");
126. } break;
127. default:
128. {
129. super.onManagerConnected(status);
130. } break;
131. }
132. }
133. };
136. @Override
137. protected void onCreate(final Bundle savedInstanceState) {
138. super.onCreate(savedInstanceState);
139. Log.v(TAG, "onCreate:");
141. getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
142. requestWindowFeature(Window.FEATURE_NO_TITLE);
143. getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
144. WindowManager.LayoutParams.FLAG_FULLSCREEN);
146. setContentView(R.layout.activity_main);
147. mCameraButton = findViewById(R.id.imageButton);
148. mCameraButton.setOnClickListener(mOnClickListener);
150. mImageView = (ImageView)findViewById(R.id.imageView);
152. mCaptureWidth = capture_solution[0][0];
153. mCaptureHeight = capture_solution[0][1];
154. bitmap = Bitmap.createBitmap(mCaptureWidth, mCaptureHeight, Bitmap.Config.RGB_565);
156. final View view = findViewById(R.id.camera_view);
157. mUVCCameraView = (CameraViewInterface)view;
158. mUVCCameraView.setAspectRatio(PREVIEW_WIDTH / (float)PREVIEW_HEIGHT);
160. synchronized (mSync) {
161. mUSBMonitor = new USBMonitor(this, mOnDeviceConnectListener);
162. mCameraHandler = UVCCameraHandler.createHandler(this, mUVCCameraView,
163. USE_SURFACE_ENCODER ? 0 : 1, PREVIEW_WIDTH, PREVIEW_HEIGHT, PREVIEW_MODE);
164. }
165. }
167. @Override
168. protected void onStart() {
169. super.onStart();
170. Log.v(TAG, "onStart:");
171. if (!OpenCVLoader.initDebug()) {
172. Log.d(TAG, "Internal OpenCV library not found. Using OpenCV Manager for initialization");
173. OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_3_0_0, this, mLoaderCallback);
174. } else {
175. Log.d(TAG, "OpenCV library found inside package. Using it!");
176. mLoaderCallback.onManagerConnected(LoaderCallbackInterface.SUCCESS);
177. }
179. synchronized (mSync) {
180. mUSBMonitor.register();
181. }
182. if (mUVCCameraView != null) {
183. mUVCCameraView.onResume();
184. }
185. }
187. @Override
188. protected void onStop() {
189. Log.v(TAG, "onStop:");
190. synchronized (mSync) {
191. mCameraHandler.close(); // #close include #stopRecording and #stopPreview
192. mUSBMonitor.unregister();
193. }
194. if (mUVCCameraView != null)
195. mUVCCameraView.onPause();
196. super.onStop();
197. }
199. @Override
200. public void onDestroy() {
201. Log.v(TAG, "onDestroy:");
202. synchronized (mSync) {
203. if (mCameraHandler != null) {
204. mCameraHandler.setPreviewCallback(null); //zhf
205. mCameraHandler.release();
206. mCameraHandler = null;
207. }
208. if (mUSBMonitor != null) {
209. mUSBMonitor.destroy();
210. mUSBMonitor = null;
211. }
212. }
213. super.onDestroy();
214. }
216. /**
217. * event handler when click camera / capture button
218. */
219. private final OnClickListener mOnClickListener = new OnClickListener() {
220. @Override
221. public void onClick(final View view) {
222. synchronized (mSync) {
223. if ((mCameraHandler != null) && !mCameraHandler.isOpened()) {
224. CameraDialog.showDialog(MainActivity.this);
225. } else {
226. mCameraHandler.close();
227. }
228. }
229. }
230. };
232. private void startPreview() {
233. synchronized (mSync) {
234. if (mCameraHandler != null) {
235. final SurfaceTexture st = mUVCCameraView.getSurfaceTexture();
236. /**
237. * 由于surfaceview由另一个线程处理，这里使用消息处理机制
238. * 对Frame进行回调处理
239. */
240. mCameraHandler.setPreviewCallback(mIFrameCallback);
241. mCameraHandler.startPreview(new Surface(st));
242. }
243. }
244. updateItems();
245. }
247. private final OnDeviceConnectListener mOnDeviceConnectListener = new OnDeviceConnectListener() {
248. @Override
249. public void onAttach(final UsbDevice device) {
250. Toast.makeText(MainActivity.this, "USB_DEVICE_ATTACHED", Toast.LENGTH_SHORT).show();
251. }
253. @Override
254. public void onConnect(final UsbDevice device, final UsbControlBlock ctrlBlock, final boolean createNew) {
255. if (DEBUG) Log.v(TAG, "onConnect:");
256. synchronized (mSync) {
257. if (mCameraHandler != null) {
258. mCameraHandler.open(ctrlBlock);
259. startPreview();
260. updateItems();
261. }
262. }
263. }
265. @Override
266. public void onDisconnect(final UsbDevice device, final UsbControlBlock ctrlBlock) {
267. if (DEBUG) Log.v(TAG, "onDisconnect:");
268. synchronized (mSync) {
269. if (mCameraHandler != null) {
270. queueEvent(new Runnable() {
271. @Override
272. public void run() {
273. try{
274. // maybe throw java.lang.IllegalStateException: already released
275. mCameraHandler.setPreviewCallback(null); //zhf
276. }
277. catch(Exception e){
278. e.printStackTrace();
279. }
280. mCameraHandler.close();
281. }
282. }, 0);
283. }
284. }
285. }
286. @Override
287. public void onDettach(final UsbDevice device) {
288. Toast.makeText(MainActivity.this, "USB_DEVICE_DETACHED", Toast.LENGTH_SHORT).show();
289. }
291. @Override
292. public void onCancel(final UsbDevice device) {
293. }
294. };
296. /**
297. * to access from CameraDialog
298. * @return
299. */
300. @Override
301. public USBMonitor getUSBMonitor() {
302. synchronized (mSync) {
303. return mUSBMonitor;
304. }
305. }
307. @Override
308. public void onDialogResult(boolean canceled) {
309. if (DEBUG) Log.v(TAG, "onDialogResult:canceled=" + canceled);
310. }
312. //================================================================================
313. private boolean isActive() {
314. return mCameraHandler != null && mCameraHandler.isOpened();
315. }
317. private boolean checkSupportFlag(final int flag) {
318. return mCameraHandler != null && mCameraHandler.checkSupportFlag(flag);
319. }
321. private int getValue(final int flag) {
322. return mCameraHandler != null ? mCameraHandler.getValue(flag) : 0;
323. }
325. private int setValue(final int flag, final int value) {
326. return mCameraHandler != null ? mCameraHandler.setValue(flag, value) : 0;
327. }
329. private int resetValue(final int flag) {
330. return mCameraHandler != null ? mCameraHandler.resetValue(flag) : 0;
331. }
333. /**
334. * 利用Activity.runOnUiThread(Runnable)把更新ui的代码创建在Runnable中，
335. * 然后在需要更新ui时，把这个Runnable对象传给Activity.runOnUiThread(Runnable)
336. */
337. private void updateItems() {
338. runOnUiThread(mUpdateItemsOnUITask, 100);
339. }
341. private final Runnable mUpdateItemsOnUITask = new Runnable() {
342. @Override
343. public void run() {
344. if (isFinishing()) return;
345. final int visible_active = isActive() ? View.VISIBLE : View.INVISIBLE;
346. mImageView.setVisibility(visible_active);
347. }
348. };
350. // if you need frame data as byte array on Java side, you can use this callback method with UVCCamera#setFrameCallback
351. // if you need to create Bitmap in IFrameCallback, please refer following snippet.
352. private Bitmap bitmap = null;//Bitmap.createBitmap(640, 480, Bitmap.Config.RGB_565);
353. private final Bitmap srcBitmap = Bitmap.createBitmap(PREVIEW_WIDTH, PREVIEW_HEIGHT, Bitmap.Config.RGB_565);
354. private String WarnText;
356. private final IFrameCallback mIFrameCallback = new IFrameCallback() {
357. @Override
358. public void onFrame(final ByteBuffer frame) {
359. frame.clear();
360. if(!isActive() || isInCapturing){
361. return;
362. }
363. if(bitmap == null){
364. Toast.makeText(MainActivity.this, "错误：Bitmap为空", Toast.LENGTH_SHORT).show();
365. return;
366. }
367. /**
368. * 这里进行opencv操作
369. * srcBitmap:源
370. * bitmap:处理后
371. */
372. synchronized (bitmap) {
373. srcBitmap.copyPixelsFromBuffer(frame);
374. WarnText = "";
376. if(bitmap.getWidth() != mCaptureWidth || bitmap.getHeight() != mCaptureHeight){
377. bitmap = Bitmap.createBitmap(mCaptureWidth, mCaptureHeight, Bitmap.Config.RGB_565);
378. }
380. Mat rgbMat = new Mat();
381. Mat grayMat = new Mat();
382. bitmap = Bitmap.createBitmap(srcBitmap.getWidth(), srcBitmap.getHeight(), Bitmap.Config.RGB_565);
383. Utils.bitmapToMat(srcBitmap, rgbMat);//convert original bitmap to Mat, R G B.
384. Imgproc.cvtColor(rgbMat, grayMat, Imgproc.COLOR_RGB2GRAY);//rgbMat to gray grayMat
385. Utils.matToBitmap(grayMat, bitmap); //convert mat to bitmap
386. Log.i(TAG, "procSrc2Gray sucess...");
388. }
389. mImageView.post(mUpdateImageTask);
390. }
391. };
393. private final Runnable mUpdateImageTask = new Runnable() {
394. @Override
395. public void run() {
396. synchronized (bitmap) {
397. mImageView.setImageBitmap(bitmap);
398. }
399. }
400. };
402. }
1. <?xml version="1.0" encoding="utf-8"?>
2. <android.support.constraint.ConstraintLayout xmlns:android="http://schemas./apk/res/android"
3. xmlns:app="http://schemas./apk/res-auto"
4. xmlns:tools="http://schemas./tools"
5. android:layout_width="match_parent"
6. android:layout_height="match_parent"
7. tools:context=".MainActivity">
9. <com.serenegiant.widget.UVCCameraTextureView
10. android:id="@+id/camera_view"
11. android:layout_width="20dp"
12. android:layout_height="16dp"
13. android:layout_centerInParent="true" />
15. <ImageView
16. android:id="@+id/imageView"
17. android:layout_width="match_parent"
18. android:layout_height="match_parent"
19. android:scaleType="fitCenter"
20. android:src="?attr/colorBackgroundFloating"
21. app:srcCompat="@color/BLACK" />
23. <ImageButton
24. android:id="@+id/imageButton"
25. android:layout_width="50dp"
26. android:layout_height="50dp"
27. android:layout_marginBottom="16dp"
28. android:background="@mipmap/ic_transparent"
29. android:scaleType="fitCenter"
30. android:src="@drawable/btn_new_shutter"
31. app:layout_constraintBottom_toBottomOf="parent"
32. app:layout_constraintEnd_toEndOf="parent"
33. app:layout_constraintStart_toStartOf="parent" />
35. </android.support.constraint.ConstraintLayout>
1. apply plugin: 'com.android.application'
3. android {
4. compileSdkVersion 27
5. defaultConfig {
6. applicationId "com.example.o0orick.camera"
7. minSdkVersion 21
8. targetSdkVersion 27
9. versionCode 1
10. versionName "1.0"
11. testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
12. }
13. buildTypes {
14. release {
15. minifyEnabled false
16. proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
17. }
18. }
19. //添加内容
20. repositories {
21. flatDir {
22. dirs 'libs'
23. }
24. }
25. }
26. dependencies {
27. implementation fileTree(dir: 'libs', include: ['*.jar'])
28. implementation 'com.android.support:appcompat-v7:27.1.1'
29. implementation 'com.android.support.constraint:constraint-layout:1.1.3'
30. testImplementation 'junit:junit:4.12'
31. androidTestImplementation 'com.android.support.test:runner:1.0.2'
32. androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
34. //添加内容，使用第三方库
35. implementation(name: 'openCVLibrary', ext: 'aar')
36. implementation(name: 'libuvccamera', ext: 'aar')
37. implementation(name: 'usbCameraCommon', ext: 'aar')
38. implementation("com.serenegiant:common:1.5.20") {
39. exclude module: 'support-v4'
40. }
41. }
1. buildscript {
3. repositories {
4. google()
5. jcenter()
6. }
7. dependencies {
8. classpath 'com.android.tools.build:gradle:3.2.0'
9. //改成自己使用的版本
10. }
11. }
13. allprojects {
14. repositories {
15. maven { url 'http://raw.github.com/saki4510t/libcommon/master/repository/' }
16. google()
17. jcenter()
18. }
19. configurations.all {
20. resolutionStrategy.eachDependency { DependencyResolveDetails details ->
21. def requested = details.requested
22. if (requested.group == 'com.android.support') {
23. if (!requested.name.startsWith("multidex")) {
24. details.useVersion '27.1.1'
25. //改成自己使用的版本
26. //将所有的三方库使用的lib版本统一
27. }
28. }
29. }
30. }
32. }
34. task clean(type: Delete) {
35. delete rootProject.buildDir
36. }

Android Studio版本：3.2

操作系统（AS）：Windows10

Android版本：5.0.2

摄像头：USB摄像头（640*480 贼辣鸡）

开源项目：saki4510t/UVCCamera、saki4510t/OpenCVwithUVC

接上篇：【UVCcamera/新手向】Android Studio编译&踩的坑

下一篇：【UVCcamera/新手向】AS中使用OpenCV进行简单人脸识别

• 运行截图

简单的灰度图

• 源码地址

 o0olele/UVCcamera-OpenCV

• 过程 

1.  新建一个camera的工程

2.  将第三方库文件（源码里有）复制到对应位置

3.  更改项目下的build.gradle

buildscript {
repositories {
google()
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:3.2.0'
//改成自己使用的版本
}
}
allprojects {
repositories {
maven { url 'http://raw.github.com/saki4510t/libcommon/master/repository/' }
google()
jcenter()
}
configurations.all {
resolutionStrategy.eachDependency { DependencyResolveDetails details ->
def requested = details.requested
if (requested.group == 'com.android.support') {
if (!requested.name.startsWith("multidex")) {
details.useVersion '27.1.1'
//改成自己使用的版本
//将所有的三方库使用的lib版本统一
}
}
}
}
}
task clean(type: Delete) {
delete rootProject.buildDir
}

4.  更改app下的build.gradle

apply plugin: 'com.android.application'
android {
compileSdkVersion 27
defaultConfig {
applicationId "com.example.o0orick.camera"
minSdkVersion 21
targetSdkVersion 27
versionCode 1
versionName "1.0"
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
//添加内容
repositories {
flatDir {
dirs 'libs'
}
}
}
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'com.android.support:appcompat-v7:27.1.1'
implementation 'com.android.support.constraint:constraint-layout:1.1.3'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.2'
androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
//添加内容，使用第三方库
implementation(name: 'openCVLibrary', ext: 'aar')
implementation(name: 'libuvccamera', ext: 'aar')
implementation(name: 'usbCameraCommon', ext: 'aar')
implementation("com.serenegiant:common:1.5.20") {
exclude module: 'support-v4'
}
}

5.  更改界面，添加camera_view(这是UVC要求的，貌似)、imageView(用于显示opencv处理后的图像)、一个button(普通、imagebutton都行)

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas./apk/res/android"
xmlns:app="http://schemas./apk/res-auto"
xmlns:tools="http://schemas./tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
	<com.serenegiant.widget.UVCCameraTextureView
		android:id="@+id/camera_view"
		android:layout_width="20dp"
		android:layout_height="16dp"
		android:layout_centerInParent="true" />
<ImageView
android:id="@+id/imageView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="fitCenter"
android:src="?attr/colorBackgroundFloating"
app:srcCompat="@color/BLACK" />
<ImageButton
android:id="@+id/imageButton"
android:layout_width="50dp"
android:layout_height="50dp"
android:layout_marginBottom="16dp"
android:background="@mipmap/ic_transparent"
android:scaleType="fitCenter"
android:src="@drawable/btn_new_shutter"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent" />
</android.support.constraint.ConstraintLayout>

6.  源代码

（部分注释，刚入门，自己的一些理解）

package com.example.o0orick.camera;
import android.animation.Animator;
import android.graphics.Bitmap;
import android.graphics.Matrix;
import android.graphics.SurfaceTexture;
import android.hardware.usb.UsbDevice;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.util.Log;
import android.view.Surface;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.view.WindowManager;
import android.widget.AdapterView;
import android.widget.CompoundButton;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.SeekBar;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.ToggleButton;
import com.serenegiant.common.BaseActivity;
import com.serenegiant.usb.CameraDialog;
import com.serenegiant.usb.IFrameCallback;
import com.serenegiant.usb.USBMonitor;
import com.serenegiant.usb.USBMonitor.OnDeviceConnectListener;
import com.serenegiant.usb.USBMonitor.UsbControlBlock;
import com.serenegiant.usb.UVCCamera;
import com.serenegiant.usbcameracommon.UVCCameraHandler;
import com.serenegiant.utils.ViewAnimationHelper;
import com.serenegiant.widget.CameraViewInterface;
import org.opencv.android.BaseLoaderCallback;
import org.opencv.android.LoaderCallbackInterface;
import org.opencv.android.OpenCVLoader;
import org.opencv.android.Utils;
import org.opencv.core.Mat;
import org.opencv.core.MatOfPoint;
import org.opencv.core.MatOfRect;
import org.opencv.core.Rect;
import org.opencv.imgproc.Imgproc;
import java.math.BigDecimal;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.List;
public final class MainActivity extends BaseActivity implements CameraDialog.CameraDialogParent {
private static final boolean DEBUG = true;	// TODO set false on release
private static final String TAG = "MainActivity";
/**
* 操作锁
*/
	private final Object mSync = new Object();
/**
* set true if you want to record movie using MediaSurfaceEncoder
* (writing frame data into Surface camera from MediaCodec
*  by almost same way as USBCameratest2)
* set false if you want to record movie using MediaVideoEncoder
*/
private static final boolean USE_SURFACE_ENCODER = false;
/**
* preview resolution(width)
* if your camera does not support specific resolution and mode,
* {@link UVCCamera#setPreviewSize(int, int, int)} throw exception
*/
private static final int PREVIEW_WIDTH = 640; // 640
/**
* preview resolution(height)
* if your camera does not support specific resolution and mode,
* {@link UVCCamera#setPreviewSize(int, int, int)} throw exception
*/
private static final int PREVIEW_HEIGHT = 480; //480
/**
* preview mode
* if your camera does not support specific resolution and mode,
* {@link UVCCamera#setPreviewSize(int, int, int)} throw exception
* 0:YUYV, other:MJPEG
*/
private static final int PREVIEW_MODE = 0; // YUV
protected static final int SETTINGS_HIDE_DELAY_MS = 2500;
/**
* for accessing USB
*/
private USBMonitor mUSBMonitor;
/**
* Handler to execute camera related methods sequentially on private thread
*/
private UVCCameraHandler mCameraHandler;
/**
* for camera preview display
*/
private CameraViewInterface mUVCCameraView;
/**
* for open&start / stop&close camera preview
*/
private ImageButton mCameraButton;
private ImageView mImageView;
private boolean isScaling = false;
private boolean isInCapturing = false;
private int[][] capture_solution = {{640,480}, {800,600},{1024,768}, {1280,1024}};
private int mCaptureWidth = capture_solution[0][0];
private int mCaptureHeight = capture_solution[0][1];
/**
* opencv的一个抽象类，为了支持opencv与app之间的相互作用，
* 该类声明了一个callback，在opencv  manager之后执行，这个回调是为了使opencv在合适的地方进行初始化
*/
private BaseLoaderCallback mLoaderCallback = new BaseLoaderCallback(this) {
@Override
public void onManagerConnected(int status) {
switch (status) {
case LoaderCallbackInterface.SUCCESS:
{
Log.i(TAG, "OpenCV loaded successfully");
} break;
default:
{
super.onManagerConnected(status);
} break;
}
}
};
@Override
protected void onCreate(final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.v(TAG, "onCreate:");
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.activity_main);
mCameraButton = findViewById(R.id.imageButton);
mCameraButton.setOnClickListener(mOnClickListener);
mImageView = (ImageView)findViewById(R.id.imageView);
mCaptureWidth = capture_solution[0][0];
mCaptureHeight = capture_solution[0][1];
bitmap = Bitmap.createBitmap(mCaptureWidth, mCaptureHeight, Bitmap.Config.RGB_565);
final View view = findViewById(R.id.camera_view);
mUVCCameraView = (CameraViewInterface)view;
mUVCCameraView.setAspectRatio(PREVIEW_WIDTH / (float)PREVIEW_HEIGHT);
		synchronized (mSync) {
	mUSBMonitor = new USBMonitor(this, mOnDeviceConnectListener);
	mCameraHandler = UVCCameraHandler.createHandler(this, mUVCCameraView,
	USE_SURFACE_ENCODER ? 0 : 1, PREVIEW_WIDTH, PREVIEW_HEIGHT, PREVIEW_MODE);
		}
}
@Override
protected void onStart() {
super.onStart();
Log.v(TAG, "onStart:");
if (!OpenCVLoader.initDebug()) {
Log.d(TAG, "Internal OpenCV library not found. Using OpenCV Manager for initialization");
OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_3_0_0, this, mLoaderCallback);
} else {
Log.d(TAG, "OpenCV library found inside package. Using it!");
mLoaderCallback.onManagerConnected(LoaderCallbackInterface.SUCCESS);
}
		synchronized (mSync) {
        	mUSBMonitor.register();
		}
		if (mUVCCameraView != null) {
  			mUVCCameraView.onResume();
		}
}
@Override
protected void onStop() {
Log.v(TAG, "onStop:");
synchronized (mSync) {
    		mCameraHandler.close();	// #close include #stopRecording and #stopPreview
			mUSBMonitor.unregister();
}
		if (mUVCCameraView != null)
			mUVCCameraView.onPause();
super.onStop();
}
@Override
public void onDestroy() {
Log.v(TAG, "onDestroy:");
synchronized (mSync) {
if (mCameraHandler != null) {
mCameraHandler.setPreviewCallback(null); //zhf
mCameraHandler.release();
mCameraHandler = null;
}
if (mUSBMonitor != null) {
mUSBMonitor.destroy();
mUSBMonitor = null;
}
}
super.onDestroy();
}
/**
* event handler when click camera / capture button
*/
private final OnClickListener mOnClickListener = new OnClickListener() {
@Override
public void onClick(final View view) {
synchronized (mSync) {
if ((mCameraHandler != null) && !mCameraHandler.isOpened()) {
CameraDialog.showDialog(MainActivity.this);
} else {
mCameraHandler.close();
}
}
}
};
private void startPreview() {
		synchronized (mSync) {
			if (mCameraHandler != null) {
final SurfaceTexture st = mUVCCameraView.getSurfaceTexture();
/**
* 由于surfaceview由另一个线程处理，这里使用消息处理机制
* 对Frame进行回调处理
*/
				mCameraHandler.setPreviewCallback(mIFrameCallback);
mCameraHandler.startPreview(new Surface(st));
			}
		}
updateItems();
}
private final OnDeviceConnectListener mOnDeviceConnectListener = new OnDeviceConnectListener() {
@Override
public void onAttach(final UsbDevice device) {
Toast.makeText(MainActivity.this, "USB_DEVICE_ATTACHED", Toast.LENGTH_SHORT).show();
}
@Override
public void onConnect(final UsbDevice device, final UsbControlBlock ctrlBlock, final boolean createNew) {
if (DEBUG) Log.v(TAG, "onConnect:");
synchronized (mSync) {
if (mCameraHandler != null) {
	mCameraHandler.open(ctrlBlock);
	startPreview();
	updateItems();
				}
}
}
@Override
public void onDisconnect(final UsbDevice device, final UsbControlBlock ctrlBlock) {
if (DEBUG) Log.v(TAG, "onDisconnect:");
synchronized (mSync) {
if (mCameraHandler != null) {
queueEvent(new Runnable() {
@Override
public void run() {
try{
// maybe throw java.lang.IllegalStateException: already released
mCameraHandler.setPreviewCallback(null); //zhf
}
catch(Exception e){
e.printStackTrace();
}
mCameraHandler.close();
}
}, 0);
				}
}
}
@Override
public void onDettach(final UsbDevice device) {
Toast.makeText(MainActivity.this, "USB_DEVICE_DETACHED", Toast.LENGTH_SHORT).show();
}
@Override
public void onCancel(final UsbDevice device) {
}
};
/**
* to access from CameraDialog
* @return
*/
@Override
public USBMonitor getUSBMonitor() {
		synchronized (mSync) {
			return mUSBMonitor;
		}
	}
@Override
public void onDialogResult(boolean canceled) {
if (DEBUG) Log.v(TAG, "onDialogResult:canceled=" + canceled);
}
//================================================================================
private boolean isActive() {
return mCameraHandler != null && mCameraHandler.isOpened();
}
private boolean checkSupportFlag(final int flag) {
return mCameraHandler != null && mCameraHandler.checkSupportFlag(flag);
}
private int getValue(final int flag) {
return mCameraHandler != null ? mCameraHandler.getValue(flag) : 0;
}
private int setValue(final int flag, final int value) {
return mCameraHandler != null ? mCameraHandler.setValue(flag, value) : 0;
}
private int resetValue(final int flag) {
return mCameraHandler != null ? mCameraHandler.resetValue(flag) : 0;
}
/**
* 利用Activity.runOnUiThread(Runnable)把更新ui的代码创建在Runnable中，
* 然后在需要更新ui时，把这个Runnable对象传给Activity.runOnUiThread(Runnable)
*/
private void updateItems() {
runOnUiThread(mUpdateItemsOnUITask, 100);
}
private final Runnable mUpdateItemsOnUITask = new Runnable() {
@Override
public void run() {
if (isFinishing()) return;
final int visible_active = isActive() ? View.VISIBLE : View.INVISIBLE;
mImageView.setVisibility(visible_active);
}
};
// if you need frame data as byte array on Java side, you can use this callback method with UVCCamera#setFrameCallback
// if you need to create Bitmap in IFrameCallback, please refer following snippet.
private Bitmap bitmap = null;//Bitmap.createBitmap(640, 480, Bitmap.Config.RGB_565);
private final Bitmap srcBitmap = Bitmap.createBitmap(PREVIEW_WIDTH, PREVIEW_HEIGHT, Bitmap.Config.RGB_565);
private String WarnText;
private final IFrameCallback mIFrameCallback = new IFrameCallback() {
@Override
public void onFrame(final ByteBuffer frame) {
frame.clear();
if(!isActive() || isInCapturing){
return;
}
if(bitmap == null){
Toast.makeText(MainActivity.this, "错误：Bitmap为空", Toast.LENGTH_SHORT).show();
return;
}
/**
* 这里进行opencv操作
* srcBitmap:源
* bitmap:处理后
*/
synchronized (bitmap) {
srcBitmap.copyPixelsFromBuffer(frame);
WarnText = "";
if(bitmap.getWidth() != mCaptureWidth || bitmap.getHeight() != mCaptureHeight){
bitmap = Bitmap.createBitmap(mCaptureWidth, mCaptureHeight, Bitmap.Config.RGB_565);
}
Mat rgbMat = new Mat();
Mat grayMat = new Mat();
bitmap = Bitmap.createBitmap(srcBitmap.getWidth(), srcBitmap.getHeight(), Bitmap.Config.RGB_565);
Utils.bitmapToMat(srcBitmap, rgbMat);//convert original bitmap to Mat, R G B.
Imgproc.cvtColor(rgbMat, grayMat, Imgproc.COLOR_RGB2GRAY);//rgbMat to gray grayMat
Utils.matToBitmap(grayMat, bitmap); //convert mat to bitmap
Log.i(TAG, "procSrc2Gray sucess...");
}
mImageView.post(mUpdateImageTask);
}
};
private final Runnable mUpdateImageTask = new Runnable() {
@Override
public void run() {
synchronized (bitmap) {
mImageView.setImageBitmap(bitmap);
}
}
};
}