我刚刚开始Android开发。我的目标是创建一个Android网络摄像头应用程序。
我从这里获取了基本代码：API Demos 我的修改后的代码包含在下面..
录制发生在点击事件上。但是我第一次点击， logcat显示我无法连接到相机..
09-25 01:29:58.580: WARN/CameraService(27788): CameraService::connect X (pid 27788) rejected (existing client).
09-25 01:29:58.580: ERROR/StagefrightRecorder(27788): Camera connection could not be established.
09-25 01:29:58.580: WARN/AACEncoder(27788): Call stop() when encoder has not started
09-25 01:29:58.580: WARN/AACEncoder(27788): [ 09-25 01:29:58.580 27788:0x6cd9 F/MPEG4Writer ]
09-25 01:29:58.580: WARN/AACEncoder(27788): frameworks/base/media/libstagefright/MPEG4Writer.cpp:2263 mCodecSpecificData
09-25 01:30:01.130: WARN/IMediaDeathNotifier(28022): media server died
09-25 01:30:01.130: WARN/AudioSystem(1351): AudioFlinger server died!
09-25 01:30:01.140: WARN/Camera(28022): ICamera died
09-25 01:30:01.140: WARN/AudioSystem(1351): AudioPolicyService server died!
09-25 01:30:01.140: WARN/Camera(28022): Camera server died!
09-25 01:30:01.150: ERROR/Camera(28022): Error 100
09-25 01:30:02.639: ERROR/AudioService(1351): Media server started.
09-25 01:30:02.639: ERROR/AudioService(1351): Media server died.
09-25 01:30:02.649: WARN/AudioPolicyManagerBase(28039): setPhoneState() setting same state 0
第二次点击开始录制，但是当录制停止时第三次点击，屏幕变黑。虽然第四次点击确实再次开始录制..
所以我不知道两件事......
我的修改代码：
public class blueCam extends Activity implements OnClickListener {
private Preview mPreview;
Camera mCamera;
int numberOfCameras;
int cameraCurrentlyLocked;
MediaRecorder recorder;
boolean recording = false;
// The first rear facing camera
int defaultCameraId;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Hide the window title.
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
// Create a RelativeLayout container that will hold a SurfaceView,
// and set it as the content of our activity.
mPreview = new Preview(this);
setContentView(mPreview);
// Find the total number of cameras available
numberOfCameras = Camera.getNumberOfCameras();
// Find the ID of the default camera
CameraInfo cameraInfo = new CameraInfo();
for (int i = 0; i < numberOfCameras; i++) {
Camera.getCameraInfo(i, cameraInfo);
if (cameraInfo.facing == CameraInfo.CAMERA_FACING_BACK) {
defaultCameraId = i;
}
}
mPreview.mSurfaceView.setClickable(true);
mPreview.mSurfaceView.setOnClickListener(this);
initRecording();
}
@Override
protected void onResume() {
super.onResume();
// Open the default i.e. the first rear facing camera.
mCamera = Camera.open();
cameraCurrentlyLocked = defaultCameraId;
mPreview.setCamera(mCamera);
}
@Override
protected void onPause() {
super.onPause();
// Because the Camera object is a shared resource, it's very
// important to release it when the activity is paused.
if (mCamera != null) {
mPreview.setCamera(null);
mCamera.release();
mCamera = null;
}
}
public void onClick(View v) {
if (recording) {
recorder.stop();
recorder.reset();
recording = false;
// Let's initRecorder so we can record again
} else {
initRecording();
prepareRecorder();
recording = true;
recorder.start();
}
}
public void prepareRecorder() {
recorder.setPreviewDisplay(mPreview.mHolder.getSurface());
try {
recorder.prepare();
} catch (IllegalStateException e) {
e.printStackTrace();
finish();
} catch (IOException e) {
e.printStackTrace();
finish();
}
}
public void initRecording()
{
String PATH_NAME="/mnt/sdcard/AshVrec.mp4";
recorder = new MediaRecorder();
recorder.setVideoSource(MediaRecorder.VideoSource.DEFAULT);
recorder.setAudioSource(MediaRecorder.AudioSource.DEFAULT);
CamcorderProfile cpHigh = CamcorderProfile.get(CamcorderProfile.QUALITY_HIGH);
recorder.setProfile(cpHigh);
recorder.setOutputFile(PATH_NAME);
recorder.setMaxDuration(50000); // 50 seconds
recorder.setMaxFileSize(5000000); // Approximately 5 megabytes
}
class Preview extends ViewGroup implements SurfaceHolder.Callback {
private final String TAG = "Preview";
SurfaceView mSurfaceView;
SurfaceHolder mHolder;
Size mPreviewSize;
List<Size> mSupportedPreviewSizes;
Camera mCamera;
Preview(Context context) {
super(context);
//initRecording();
mSurfaceView = new SurfaceView(context);
addView(mSurfaceView);
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
mHolder = mSurfaceView.getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void setCamera(Camera camera) {
mCamera = camera;
if (mCamera != null) {
mSupportedPreviewSizes = mCamera.getParameters().getSupportedPreviewSizes();
requestLayout();
}
}
public void switchCamera(Camera camera) {
setCamera(camera);
try {
camera.setPreviewDisplay(mHolder);
} catch (IOException exception) {
Log.e(TAG, "IOException caused by setPreviewDisplay()", exception);
}
Camera.Parameters parameters = camera.getParameters();
parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
requestLayout();
camera.setParameters(parameters);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// We purposely disregard child measurements because act as a
// wrapper to a SurfaceView that centers the camera preview instead
// of stretching it.
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 l, int t, int r, int b) {
if (changed && getChildCount() > 0) {
final View child = getChildAt(0);
final int width = r - l;
final int height = b - t;
int previewWidth = width;
int previewHeight = height;
if (mPreviewSize != null) {
previewWidth = mPreviewSize.width;
previewHeight = mPreviewSize.height;
}
// Center the child SurfaceView within the parent.
if (width * previewHeight > height * previewWidth) {
final int scaledChildWidth = previewWidth * height / previewHeight;
child.layout((width - scaledChildWidth) / 2, 0,
(width + scaledChildWidth) / 2, height);
} else {
final int scaledChildHeight = previewHeight * width / previewWidth;
child.layout(0, (height - scaledChildHeight) / 2,
width, (height + scaledChildHeight) / 2);
}
}
}
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);
}
//prepareRecorder();
}
public void surfaceDestroyed(SurfaceHolder holder) {
// Surface will be destroyed when we return, so stop the preview.
if (mCamera != null) {
mCamera.stopPreview();
}
recorder.stop();
recorder.reset();
recorder.release();
}
private Size getOptimalPreviewSize(List<Size> sizes, int w, int h) {
final double ASPECT_TOLERANCE = 0.1;
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;
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
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;
}
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
// Now that the size is known, set up the camera parameters and begin
// the preview.
Camera.Parameters parameters = mCamera.getParameters();
parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
requestLayout();
mCamera.setParameters(parameters);
mCamera.startPreview();
}
}
}
任何帮助都是值得的。 感谢。