Android相机将无法正常工作。 startPreview失败

我从LogCat中得到这些错误：

10-30 00:31:51.494: D/CameraHal(1205): CameraHal setOverlay/1/00000000/00000000 10-30 00:31:51.494: E/CameraHal(1205): Trying to set overlay, but overlay is null!, line:3472 10-30 00:31:51.494: W/CameraService(1205): Overlay create failed - retrying ... 10-30 00:31:52.526: E/CameraService(1205): Overlay Creation Failed! ... 10-30 00:31:52.588: E/AndroidRuntime(5040): FATAL EXCEPTION: main 10-30 00:31:52.588: E/AndroidRuntime(5040): java.lang.RuntimeException: startPreview failed 10-30 00:31:52.588: E/AndroidRuntime(5040): at android.hardware.Camera.startPreview(Native Method) 10-30 00:31:52.588: E/AndroidRuntime(5040): at com.matthewmitchell.nightcam.CameraSurfaceView.surfaceCreated(CameraSurfaceView.java:47) 10-30 00:31:52.588: E/AndroidRuntime(5040): at android.view.SurfaceView.updateWindow(SurfaceView.java:544) 10-30 00:31:52.588: E/AndroidRuntime(5040): at android.view.SurfaceView.dispatchDraw(SurfaceView.java:341) 10-30 00:31:52.588: E/AndroidRuntime(5040): at android.view.ViewGroup.drawChild(ViewGroup.java:1638) 10-30 00:31:52.588: E/AndroidRuntime(5040): at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1367) 10-30 00:31:52.588: E/AndroidRuntime(5040): at android.view.View.draw(View.java:6743) 10-30 00:31:52.588: E/AndroidRuntime(5040): at android.widget.FrameLayout.draw(FrameLayout.java:352) 10-30 00:31:52.588: E/AndroidRuntime(5040): at android.view.ViewGroup.drawChild(ViewGroup.java:1640) 10-30 00:31:52.588: E/AndroidRuntime(5040): at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1367) 10-30 00:31:52.588: E/AndroidRuntime(5040): at android.view.ViewGroup.drawChild(ViewGroup.java:1638) 10-30 00:31:52.588: E/AndroidRuntime(5040): at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1367) 10-30 00:31:52.588: E/AndroidRuntime(5040): at android.view.View.draw(View.java:6743) 10-30 00:31:52.588: E/AndroidRuntime(5040): at android.widget.FrameLayout.draw(FrameLayout.java:352) 10-30 00:31:52.588: E/AndroidRuntime(5040): at com.android.internal.policy.impl.PhoneWindow$DecorView.draw(PhoneWindow.java:1876) 10-30 00:31:52.588: E/AndroidRuntime(5040): at android.view.ViewRoot.draw(ViewRoot.java:1407) 10-30 00:31:52.588: E/AndroidRuntime(5040): at android.view.ViewRoot.performTraversals(ViewRoot.java:1163) 10-30 00:31:52.588: E/AndroidRuntime(5040): at android.view.ViewRoot.handleMessage(ViewRoot.java:1727) 10-30 00:31:52.588: E/AndroidRuntime(5040): at android.os.Handler.dispatchMessage(Handler.java:99) 10-30 00:31:52.588: E/AndroidRuntime(5040): at android.os.Looper.loop(Looper.java:123) 10-30 00:31:52.588: E/AndroidRuntime(5040): at android.app.ActivityThread.main(ActivityThread.java:4627) 10-30 00:31:52.588: E/AndroidRuntime(5040): at java.lang.reflect.Method.invokeNative(Native Method) 10-30 00:31:52.588: E/AndroidRuntime(5040): at java.lang.reflect.Method.invoke(Method.java:521) 10-30 00:31:52.588: E/AndroidRuntime(5040): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 10-30 00:31:52.588: E/AndroidRuntime(5040): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 10-30 00:31:52.588: E/AndroidRuntime(5040): at dalvik.system.NativeStart.main(Native Method) 

这里是Activity类：

 public class NightCamActivity extends Activity { private GLSurfaceView mGLView; CameraSurfaceView surface_view; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); // Create a GLSurfaceView instance and set it // as the ContentView for this Activity Debug.out("Welcome"); surface_view = new CameraSurfaceView(this); mGLView = new MySurfaceView(this); setContentView(mGLView); addContentView(surface_view, new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT)); } @Override protected void onPause() { super.onPause(); // The following call pauses the rendering thread. // If your OpenGL application is memory intensive, // you should consider de-allocating objects that // consume significant memory here. mGLView.onPause(); } @Override protected void onResume() { super.onResume(); // The following call resumes a paused rendering thread. // If you de-allocated graphic objects for onPause() // this is a good place to re-allocate them. mGLView.onResume(); } } 

MySurfaceView类：

 class MySurfaceView extends GLSurfaceView{ public MySurfaceView(NightCamActivity context){ super(context); // Create an OpenGL ES 2.0 context. Debug.out("Mysurfaceview welcome"); setEGLContextClientVersion(2); // Set the Renderer for drawing on the GLSurfaceView MyRenderer renderer = new MyRenderer(); renderer.takeContext(context); context.surface_view.renderer = renderer; setRenderer(renderer); } } 

CameraSurfaceView类：

 public class CameraSurfaceView extends SurfaceView implements SurfaceHolder.Callback, PreviewCallback { private Camera camera; Camera.Size use_size; MyRenderer renderer; public CameraSurfaceView(Context context) { super(context); SurfaceHolder holder = getHolder(); holder.addCallback(this); Debug.out("Init CSV"); camera = Camera.open(); } public void surfaceCreated(SurfaceHolder holder) { Debug.out("SC"); try { camera.setPreviewDisplay(holder); } catch (IOException e) { Debug.out("Could not set preview display for camera."); } camera.setPreviewCallback(this); } public void surfaceDestroyed(SurfaceHolder holder) { // Surface will be destroyed when we return, so stop the preview. // Because the CameraDevice object is not a shared resource, it's very // important to release it when the activity is paused. try { if (camera != null) { camera.stopPreview(); camera.release(); } } catch (Exception e) { Debug.out("Camera release failure."); } } public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) { Camera.Parameters parameters = camera.getParameters(); List<Camera.Size> supportedPreviewSizes = parameters.getSupportedPreviewSizes(); Camera.Size optimalPreviewSize = getOptimalPreviewSize(supportedPreviewSizes, w, h); if (optimalPreviewSize != null) { parameters.setPreviewSize(optimalPreviewSize.width, optimalPreviewSize.height); camera.setParameters(parameters); camera.startPreview(); } } static Camera.Size getOptimalPreviewSize(List<Camera.Size> sizes, int w, int h) { final double ASPECT_TOLERANCE = 0.1; final double MAX_DOWNSIZE = 1.5; double targetRatio = (double) w / h; if (sizes == null) return null; Camera.Size optimalSize = null; double minDiff = Double.MAX_VALUE; int targetHeight = h; // Try to find an size match aspect ratio and size for (Camera.Size size : sizes) { double ratio = (double) size.width / size.height; double downsize = (double) size.width / w; if (downsize > MAX_DOWNSIZE) { //if the preview is a lot larger than our display surface ignore it //reason - on some phones there is not enough heap available to show the larger preview sizes continue; } if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE) continue; if (Math.abs(size.height - targetHeight) < minDiff) { optimalSize = size; minDiff = Math.abs(size.height - targetHeight); } } // Cannot find the one match the aspect ratio, ignore the requirement //keep the max_downsize requirement if (optimalSize == null) { minDiff = Double.MAX_VALUE; for (Camera.Size size : sizes) { double downsize = (double) size.width / w; if (downsize > MAX_DOWNSIZE) { continue; } if (Math.abs(size.height - targetHeight) < minDiff) { optimalSize = size; minDiff = Math.abs(size.height - targetHeight); } } } //everything else failed, just take the closest match if (optimalSize == null) { minDiff = Double.MAX_VALUE; for (Camera.Size size : sizes) { if (Math.abs(size.height - targetHeight) < minDiff) { optimalSize = size; minDiff = Math.abs(size.height - targetHeight); } } } return optimalSize; } public void onPreviewFrame(byte[] data, Camera arg1) { Debug.out("PREVIEW FRAME:"); byte[] pixels = new byte[use_size.width * use_size.height * 3]; ; decodeYUV420SP(pixels, data, use_size.width, use_size.height); renderer.bindCameraTexture(pixels, use_size.width, use_size.height); } void decodeYUV420SP(byte[] rgb, byte[] yuv420sp, int width, int height) { final int frameSize = width * height; for (int j = 0, yp = 0; j < height; j++) { int uvp = frameSize + (j >> 1) * width, u = 0, v = 0; for (int i = 0; i < width; i++, yp++) { int y = (0xff & ((int) yuv420sp[yp])) - 16; if (y < 0){ y = 0; } if ((i & 1) == 0) { v = (0xff & yuv420sp[uvp++]) - 128; u = (0xff & yuv420sp[uvp++]) - 128; } int y1192 = 1192 * y; int r = (y1192 + 1634 * v); int g = (y1192 - 833 * v - 400 * u); int b = (y1192 + 2066 * u); if (r < 0){ r = 0; }else if (r > 262143){ r = 262143; } if (g < 0){ g = 0; }else if (g > 262143){ g = 262143; } if (b < 0){ b = 0; }else if (b > 262143){ b = 262143; } rgb[yp*3] = (byte) (b << 6); rgb[yp*3 + 1] = (byte) (b >> 2); rgb[yp*3 + 2] = (byte) (b >> 10); } } } } 

最后是MyRender类：

 public class MyRenderer implements GLSurfaceView.Renderer{ private FloatBuffer vertices; private FloatBuffer texcoords; private int mProgram; private int maPositionHandle; private int gvTexCoordHandle; private int gvSamplerHandle; private static Context context; int[] camera_texture; public void onSurfaceCreated(GL10 unused, EGLConfig config) { initShapes(); GLES20.glClearColor(0.0f, 1.0f, 0.2f, 1.0f); Debug.out("Hello init."); //Shaders int vertexShader = 0; int fragmentShader = 0; try { vertexShader = loadShader(GLES20.GL_VERTEX_SHADER, readFile("vertex.vsh")); fragmentShader = loadShader(GLES20.GL_FRAGMENT_SHADER, readFile("fragment.fsh")); } catch (IOException e) { Debug.out("The shaders could not be found."); e.printStackTrace(); } mProgram = GLES20.glCreateProgram(); // create empty OpenGL Program GLES20.glAttachShader(mProgram, vertexShader); // add the vertex shader to program GLES20.glAttachShader(mProgram, fragmentShader); // add the fragment shader to program GLES20.glLinkProgram(mProgram); // creates OpenGL program executables // get handles maPositionHandle = GLES20.glGetAttribLocation(mProgram, "vPosition"); gvTexCoordHandle = GLES20.glGetAttribLocation(mProgram, "a_texCoord"); gvSamplerHandle = GLES20.glGetAttribLocation(mProgram, "s_texture"); GLES20.glPixelStorei(GLES20.GL_UNPACK_ALIGNMENT, 1); camera_texture = null; } private void initShapes(){ float triangleCoords[] = { // X, Y, Z -1.0f, -1.0f, 0.0f, 1.0f, -1.0f, 0.0f, -1.0f, 1.0f, 0.0f, 1.0f, 1.0f, 0.0f, }; float texcoordf[] = { // X, Y, Z -1.0f,-1.0f, 1.0f,-1.0f, -1.0f,1.0f, 1.0f,1.0f, }; // initialize vertex Buffer for vertices ByteBuffer vbb = ByteBuffer.allocateDirect(triangleCoords.length * 4); vbb.order(ByteOrder.nativeOrder());// use the device hardware's native byte order vertices = vbb.asFloatBuffer(); // create a floating point buffer from the ByteBuffer vertices.put(triangleCoords); // add the coordinates to the FloatBuffer vertices.position(0); // set the buffer to read the first coordinate // initialize vertex Buffer for texcoords vbb = ByteBuffer.allocateDirect(texcoordf.length * 4); vbb.order(ByteOrder.nativeOrder());// use the device hardware's native byte order texcoords = vbb.asFloatBuffer(); // create a floating point buffer from the ByteBuffer texcoords.put(texcoordf); // add the coordinates to the FloatBuffer texcoords.position(0); // set the buffer to read the first coordinate } private static String readFile(String path) throws IOException { AssetManager assetManager = context.getAssets(); InputStream stream = assetManager.open(path); try { return new Scanner(stream).useDelimiter("\\A").next(); } finally { stream.close(); } } private int loadShader(int type, String shaderCode){ // create a vertex shader type (GLES20.GL_VERTEX_SHADER) // or a fragment shader type (GLES20.GL_FRAGMENT_SHADER) int shader = GLES20.glCreateShader(type); // add the source code to the shader and compile it GLES20.glShaderSource(shader, shaderCode); GLES20.glCompileShader(shader); return shader; } public void onDrawFrame(GL10 unused) { GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT | GLES20.GL_DEPTH_BUFFER_BIT); if(camera_texture == null){ return; } // Add program to OpenGL environment GLES20.glUseProgram(mProgram); // Prepare the triangle data GLES20.glVertexAttribPointer(maPositionHandle, 3, GLES20.GL_FLOAT, false, 0, vertices); GLES20.glVertexAttribPointer(gvTexCoordHandle, 2, GLES20.GL_FLOAT, false, 0, texcoords); GLES20.glEnableVertexAttribArray(maPositionHandle); GLES20.glEnableVertexAttribArray(gvTexCoordHandle); GLES20.glActiveTexture(GLES20.GL_TEXTURE0); GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, camera_texture[0]); GLES20.glUniform1i(gvSamplerHandle, 0); // Draw the triangle GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4); GLES20.glDisableVertexAttribArray(maPositionHandle); GLES20.glDisableVertexAttribArray(gvTexCoordHandle); } public void onSurfaceChanged(GL10 unused, int width, int height) { GLES20.glViewport(0, 0, width, height); } public void takeContext(Context ocontext) { Debug.out("Take context"); context = ocontext; } void bindCameraTexture(byte[] data,int w,int h) { byte[] pixels = new byte[256*256*3]; for(int x = 0;x < 256;x++){ for(int y = 0;x < 256;x++){ pixels[x*256+y] = data[x*w+y]; } } if (camera_texture==null){ camera_texture=new int[1]; }else{ GLES20.glDeleteTextures(1, camera_texture, 0); } GLES20.glGenTextures(1, camera_texture, 0); int tex = camera_texture[0]; GLES20.glBindTexture(GL10.GL_TEXTURE_2D, tex); GLES20.glTexImage2D(GL10.GL_TEXTURE_2D, 0, GL10.GL_RGB, 256, 256, 0, GL10.GL_RGB, GL10.GL_UNSIGNED_BYTE, ByteBuffer.wrap(pixels)); GLES20.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER, GL10.GL_LINEAR); } } 

Answer 1

我把你的代码拿到了和你一样的错误。 然而，在debugging时，在我看来，预览可能会失败，因为它看起来像宽度和高度尺寸是错误的方式，但不仅仅是切换它们的情况，因为我认为方向也起作用。

无论如何，我用我自己的（见下文）取代你的CameraSurfaceView，我认为它现在可以工作。 有没有例外，但屏幕是完全明亮的绿色（我想这可能是因为我没有vertex.vsh或fragment.vsh文件。

 package stackOverflow.test; import java.io.IOException; import java.util.List; import android.content.Context; import android.hardware.Camera; import android.hardware.Camera.Size; import android.util.AttributeSet; import android.util.Log; import android.view.Display; import android.view.Surface; import android.view.SurfaceHolder; import android.view.SurfaceView; import android.view.View; import android.view.ViewGroup; import android.view.WindowManager; public class CameraSurfaceView extends ViewGroup implements SurfaceHolder.Callback { private Size mPreviewSize; private List<Size> mSupportedPreviewSizes; private Context mContext; private SurfaceView mSurfaceView; private SurfaceHolder mHolder; private final String TAG = "CameraSurfaceView"; private Camera mCamera; private List<String> mSupportedFlashModes; public CameraSurfaceView(Context context) { super(context); mContext = context; mCamera = Camera.open(); setCamera(mCamera); mSurfaceView = new SurfaceView(context); addView(mSurfaceView, 0); mHolder = mSurfaceView.getHolder(); mHolder.addCallback(this); mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); mHolder.setKeepScreenOn(true); } public CameraSurfaceView(Context context, AttributeSet attrs) { super(context, attrs); mContext = context; } public void setSupportedPreviewSizes(List<Size> supportedPreviewSizes) { mSupportedPreviewSizes = supportedPreviewSizes; } public Size getPreviewSize() { return mPreviewSize; } public void setCamera(Camera camera) { mCamera = camera; if (mCamera != null) { mSupportedPreviewSizes = mCamera.getParameters().getSupportedPreviewSizes(); mSupportedFlashModes = mCamera.getParameters().getSupportedFlashModes(); // Set the camera to Auto Flash mode. if (mSupportedFlashModes.contains(Camera.Parameters.FLASH_MODE_AUTO)) { Camera.Parameters parameters = mCamera.getParameters(); parameters.setFlashMode(Camera.Parameters.FLASH_MODE_AUTO); mCamera.setParameters(parameters); } } requestLayout(); } @Override public void surfaceDestroyed(SurfaceHolder holder) { // Surface will be destroyed when we return, so stop the preview. if (mCamera != null) { mCamera.stopPreview(); } } @Override public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { // Now that the size is known, set up the camera parameters and begin // the preview. if (mCamera != null) { Camera.Parameters parameters = mCamera.getParameters(); Size previewSize = getPreviewSize(); parameters.setPreviewSize(previewSize.width, previewSize.height); mCamera.setParameters(parameters); mCamera.startPreview(); } } @Override public void surfaceCreated(SurfaceHolder holder) { // The Surface has been created, acquire the camera and tell it where // to draw. try { if (mCamera != null) { mCamera.setPreviewDisplay(holder); } } catch (IOException exception) { Log.e(TAG, "IOException caused by setPreviewDisplay()", exception); } } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { final int width = resolveSize(getSuggestedMinimumWidth(), widthMeasureSpec); final int height = resolveSize(getSuggestedMinimumHeight(), heightMeasureSpec); setMeasuredDimension(width, height); if (mSupportedPreviewSizes != null) { mPreviewSize = getOptimalPreviewSize(mSupportedPreviewSizes, width, height); } } @Override protected void onLayout(boolean changed, int left, int top, int right, int bottom) { if (changed) { final View cameraView = getChildAt(0); final int width = right - left; final int height = bottom - top; int previewWidth = width; int previewHeight = height; if (mPreviewSize != null) { Display display = ((WindowManager)mContext.getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay(); switch (display.getRotation()) { case Surface.ROTATION_0: previewWidth = mPreviewSize.height; previewHeight = mPreviewSize.width; mCamera.setDisplayOrientation(90); break; case Surface.ROTATION_90: previewWidth = mPreviewSize.width; previewHeight = mPreviewSize.height; break; case Surface.ROTATION_180: previewWidth = mPreviewSize.height; previewHeight = mPreviewSize.width; break; case Surface.ROTATION_270: previewWidth = mPreviewSize.width; previewHeight = mPreviewSize.height; mCamera.setDisplayOrientation(180); break; } } final int scaledChildHeight = previewHeight * width / previewWidth; cameraView.layout(0, height - scaledChildHeight, width, height); } } private Size getOptimalPreviewSize(List<Size> sizes, int width, int height) { Size optimalSize = null; final double ASPECT_TOLERANCE = 0.1; double targetRatio = (double) height / width; // Try to find a size match which suits the whole screen minus the menu on the left. for (Size size : sizes) { if (size.height != width) continue; double ratio = (double) size.width / size.height; if (ratio <= targetRatio + ASPECT_TOLERANCE && ratio >= targetRatio - ASPECT_TOLERANCE) { optimalSize = size; } } // If we cannot find the one that matches the aspect ratio, ignore the requirement. if (optimalSize == null) { // TODO : Backup in case we don't get a size. } return optimalSize; } public void previewCamera() { try { mCamera.setPreviewDisplay(mHolder); mCamera.startPreview(); } catch(Exception e) { Log.d(TAG, "Cannot start preview.", e); } } /*public void onPreviewFrame(byte[] data, Camera arg1) { Log.d("CameraSurfaceView", "PREVIEW FRAME:"); byte[] pixels = new byte[use_size.width * use_size.height * 3]; ; decodeYUV420SP(pixels, data, use_size.width, use_size.height); renderer.bindCameraTexture(pixels, use_size.width, use_size.height); }*/ void decodeYUV420SP(byte[] rgb, byte[] yuv420sp, int width, int height) { final int frameSize = width * height; for (int j = 0, yp = 0; j < height; j++) { int uvp = frameSize + (j >> 1) * width, u = 0, v = 0; for (int i = 0; i < width; i++, yp++) { int y = (0xff & ((int) yuv420sp[yp])) - 16; if (y < 0){ y = 0; } if ((i & 1) == 0) { v = (0xff & yuv420sp[uvp++]) - 128; u = (0xff & yuv420sp[uvp++]) - 128; } int y1192 = 1192 * y; int r = (y1192 + 1634 * v); int g = (y1192 - 833 * v - 400 * u); int b = (y1192 + 2066 * u); if (r < 0){ r = 0; }else if (r > 262143){ r = 262143; } if (g < 0){ g = 0; }else if (g > 262143){ g = 262143; } if (b < 0){ b = 0; }else if (b > 262143){ b = 262143; } rgb[yp*3] = (byte) (b << 6); rgb[yp*3 + 1] = (byte) (b >> 2); rgb[yp*3 + 2] = (byte) (b >> 10); } } } } 

你会注意到我的onPreviewFrame（）方法只是为了让它运行，还有context.surface_view.renderer = renderer。

我不熟悉OpenGL库，但也许这足以让你再次。

Answer 2

我有同样的问题，并删除/播放预览大小设置不适合我。 我通过下一行代码来修复它：

 mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); 

现在对我来说工作正常！

Answer 3

检查你的logcat的东西类似于这个，就在你的exception之前：

 11-02 09:25:44.305: ERROR/QualcommCameraHardware(56): failed to construct master heap for pmem pool /dev/pmem_adsp 11-02 09:25:44.305: ERROR/QualcommCameraHardware(56): initPreview X: could not initialize preview heap. 11-02 09:25:44.305: ERROR/QualcommCameraHardware(56): startPreview X initPreview failed. Not starting preview. 

当我尝试设置预览大小为1024×768时，发生在横向方向上的手机上。 getSupportedPreviewSizes（）方法表示支持这个大小，但是操作系统似乎无法为预览分配足够的内存。 设置一个较小的尺寸确实有效。

另外，请尝试下面的代码。 你应该从surfaceChanged（）方法调用startPreview（），那么你的SurfaceView的尺寸是已知的。 从surfaceCreated（）调用它还为时过早。

使用它可以确定给定大小的SurfaceView的最佳预览大小（根据Google CameraPreview示例进行调整）

 static Size getOptimalPreviewSize(List<Size> sizes, int w, int h) { final double ASPECT_TOLERANCE = 0.1; final double MAX_DOWNSIZE = 1.5; double targetRatio = (double) w / h; if (sizes == null) return null; Size optimalSize = null; double minDiff = Double.MAX_VALUE; int targetHeight = h; // Try to find an size match aspect ratio and size for (Size size : sizes) { double ratio = (double) size.width / size.height; double downsize = (double) size.width / w; if (downsize > MAX_DOWNSIZE) { //if the preview is a lot larger than our display surface ignore it //reason - on some phones there is not enough heap available to show the larger preview sizes continue; } if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE) continue; if (Math.abs(size.height - targetHeight) < minDiff) { optimalSize = size; minDiff = Math.abs(size.height - targetHeight); } } // Cannot find the one match the aspect ratio, ignore the requirement //keep the max_downsize requirement if (optimalSize == null) { minDiff = Double.MAX_VALUE; for (Size size : sizes) { double downsize = (double) size.width / w; if (downsize > MAX_DOWNSIZE) { continue; } if (Math.abs(size.height - targetHeight) < minDiff) { optimalSize = size; minDiff = Math.abs(size.height - targetHeight); } } } //everything else failed, just take the closest match if (optimalSize == null) { minDiff = Double.MAX_VALUE; for (Size size : sizes) { if (Math.abs(size.height - targetHeight) < minDiff) { optimalSize = size; minDiff = Math.abs(size.height - targetHeight); } } } return optimalSize; } 

你可以从你的surfaceChanged（）方法调用它，就像这样：

 public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) { Camera.Parameters parameters = camera.getParameters(); List<Size> supportedPreviewSizes = parameters.getSupportedPreviewSizes(); Size optimalPreviewSize = getOptimalPreviewSize(supportedPreviewSizes, w, h); if (optimalPreviewSize != null) { parameters.setPreviewSize(optimalPreviewSize.width, optimalPreviewSize.height); camera.setParameters(parameters); camera.startPreview(); } } 

Answer 4

尝试在initCamera（）中设置Surface的types。

 private void initCamera() { mCamSV = (SurfaceView)findViewById(R.id.surface_camera); mCamSH = mCamSV.getHolder(); mCamSH.addCallback(this); **mCamSH.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);** } 

编辑1

我在这里复制所有的文件，这与我的android 2.2 sdk工作

活动

 package com.stack.camera; import java.io.IOException; import android.app.Activity; import android.hardware.Camera; import android.os.Bundle; import android.view.SurfaceHolder; import android.view.SurfaceView; import android.view.WindowManager; import android.widget.FrameLayout; public class CameraStackActivity extends Activity implements SurfaceHolder.Callback { private Camera mCam; private SurfaceView mCamSV; private SurfaceHolder mCamSH; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN); setContentView(R.layout.main); initCamera(); } @Override public void onDestroy() { stopCamera(); } public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { startCamera(holder, width, height); } public void surfaceCreated(SurfaceHolder holder) { // TODO Auto-generated method stub mCam = Camera.open(); try { mCam.setPreviewDisplay(holder); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } public void surfaceDestroyed(SurfaceHolder holder) { // TODO Auto-generated method stub } private void initCamera() { mCamSV = (SurfaceView)findViewById(R.id.surface_camera); mCamSH = mCamSV.getHolder(); mCamSH.addCallback(this); mCamSH.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); } private void startCamera(SurfaceHolder sh, int width, int height) { Camera.Parameters p = mCam.getParameters(); // Camera.Size s = p.getSupportedPreviewSizes().get(0); p.setPreviewSize(width, height); mCam.setParameters(p); try { mCam.setPreviewDisplay(sh); } catch (Exception e) { } mCam.startPreview(); } private void stopCamera() { mCamSH.removeCallback(this); mCam.stopPreview(); mCam.release(); } } 

布局

 <?xml version="1.0" encoding="utf-8"?> <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <SurfaceView android:id="@+id/surface_camera" android:layout_width="fill_parent" android:layout_height="fill_parent" /> </FrameLayout> 

清单文件

 <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.stack.camera" android:versionCode="1" android:versionName="1.0"> <uses-permission android:name="android.permission.CAMERA" /> <uses-feature android:name="android.hardware.camera" /> <uses-feature android:name="android.hardware.camera.autofocus" /> <application android:icon="@drawable/icon" android:label="@string/app_name"> <activity android:name="CameraStackActivity" android:label="@string/app_name"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> </manifest> 

Answer 5

与OP问题并不真正相关，但是…

我已经看到了下面的问题给我java.io.IOException: setPreviewDisplay failed ：

如果你同时做video和照片，有两个函数， camera.unlock（）和camera.reconnect （） 。 在拍摄照片之前，您必须在录制video和camera.reconnect（）之前使用camera.unlock（） 。

Answer 6

我对这个游戏有点晚了，但是我正在运行cordova，并且有两个插件试图同时注册相机。

不知道这是否会用于除我以外的任何人。

Answer 7

简单的解决scheme：在你的CameraSurfaceView类中添加这一行：

 holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); 

在这些线下：

 SurfaceHolder holder = getHolder(); holder.addCallback(this);