我正在创建自定义相机应用。我的TextureView的高度设置为300 dp。
我想将视频分辨率设置为640 x 480，预览高度为300dp（TextureView Height）。
我希望相机预览能够填充该区域而不会拉伸或裁切。我该如何实现？
public class VideoActivity extends AppCompatActivity{
private static final int SENSOR_ORIENTATION_DEFAULT_DEGREES = 90;
private static final int SENSOR_ORIENTATION_INVERSE_DEGREES = 270;
private static final SparseIntArray DEFAULT_ORIENTATIONS = new SparseIntArray();
private static final SparseIntArray INVERSE_ORIENTATIONS = new SparseIntArray();
private static final String TAG = "Camera2VideoFragment";
private static final int REQUEST_VIDEO_PERMISSIONS = 1;
private static final String FRAGMENT_DIALOG = "dialog";
private static final String[] VIDEO_PERMISSIONS = {
Manifest.permission.CAMERA,
Manifest.permission.RECORD_AUDIO,
};
static {
DEFAULT_ORIENTATIONS.append(Surface.ROTATION_0, 90);
DEFAULT_ORIENTATIONS.append(Surface.ROTATION_90, 0);
DEFAULT_ORIENTATIONS.append(Surface.ROTATION_180, 270);
DEFAULT_ORIENTATIONS.append(Surface.ROTATION_270, 180);
}
static {
INVERSE_ORIENTATIONS.append(Surface.ROTATION_0, 270);
INVERSE_ORIENTATIONS.append(Surface.ROTATION_90, 180);
INVERSE_ORIENTATIONS.append(Surface.ROTATION_180, 90);
INVERSE_ORIENTATIONS.append(Surface.ROTATION_270, 0);
}
private AutoFitTextureView mTextureView;
private CameraDevice mCameraDevice;
/**
* A reference to the current {@link android.hardware.camera2.CameraCaptureSession} for
* preview.
*/
private CameraCaptureSession mPreviewSession;
/**
* {@link TextureView.SurfaceTextureListener} handles several lifecycle events on a
* {@link TextureView}.
*/
private TextureView.SurfaceTextureListener mSurfaceTextureListener
= new TextureView.SurfaceTextureListener() {
@Override
public void onSurfaceTextureAvailable(SurfaceTexture surfaceTexture,
int width, int height) {
openCamera(width, height);
}
@Override
public void onSurfaceTextureSizeChanged(SurfaceTexture surfaceTexture,
int width, int height) {
configureTransform(width, height);
}
@Override
public boolean onSurfaceTextureDestroyed(SurfaceTexture surfaceTexture) {
return true;
}
@Override
public void onSurfaceTextureUpdated(SurfaceTexture surfaceTexture) {
}
};
/**
* The {@link android.util.Size} of camera preview.
*/
private Size mPreviewSize;
/**
* The {@link android.util.Size} of video recording.
*/
private Size mVideoSize;
/**
* MediaRecorder
*/
private MediaRecorder mMediaRecorder;
/**
* Whether the app is recording video now
*/
private boolean mIsRecordingVideo;
/**
* An additional thread for running tasks that shouldn't block the UI.
*/
private HandlerThread mBackgroundThread;
/**
* A {@link Handler} for running tasks in the background.
*/
private Handler mBackgroundHandler;
/**
* A {@link Semaphore} to prevent the app from exiting before closing the camera.
*/
private Semaphore mCameraOpenCloseLock = new Semaphore(1);
/**
* {@link CameraDevice.StateCallback} is called when {@link CameraDevice} changes its status.
*/
private CameraDevice.StateCallback mStateCallback = new CameraDevice.StateCallback() {
@Override
public void onOpened(@NonNull CameraDevice cameraDevice) {
mCameraDevice = cameraDevice;
startPreview();
mCameraOpenCloseLock.release();
if (null != mTextureView) {
configureTransform(mTextureView.getWidth(), mTextureView.getHeight());
}
}
@Override
public void onDisconnected(@NonNull CameraDevice cameraDevice) {
mCameraOpenCloseLock.release();
cameraDevice.close();
mCameraDevice = null;
}
@Override
public void onError(@NonNull CameraDevice cameraDevice, int error) {
mCameraOpenCloseLock.release();
cameraDevice.close();
mCameraDevice = null;
Activity activity = VideoActivity.this;
if (null != activity) {
activity.finish();
}
}
};
private Integer mSensorOrientation;
private String mNextVideoAbsolutePath;
private CaptureRequest.Builder mPreviewBuilder;
/**
* In this sample, we choose a video size with 3x4 aspect ratio. Also, we don't use sizes
* larger than 1080p, since MediaRecorder cannot handle such a high-resolution video.
*
* @param choices The list of available sizes
* @return The video size
*/
private static Size chooseVideoSize(Size[] choices) {
for (Size size : choices) {
if (size.getWidth() == size.getHeight() * 4 / 3 && size.getWidth() <= 1080) {
return size;
}
}
Log.e(TAG, "Couldn't find any suitable video size");
return choices[choices.length - 1];
}
/**
* Given {@code choices} of {@code Size}s supported by a camera, chooses the smallest one whose
* width and height are at least as large as the respective requested values, and whose aspect
* ratio matches with the specified value.
*
* @param choices The list of sizes that the camera supports for the intended output class
* @param width The minimum desired width
* @param height The minimum desired height
* @param aspectRatio The aspect ratio
* @return The optimal {@code Size}, or an arbitrary one if none were big enough
*/
private static Size chooseOptimalSize(Size[] choices, int width, int height, Size aspectRatio) {
// Collect the supported resolutions that are at least as big as the preview Surface
List<Size> bigEnough = new ArrayList<>();
int w = aspectRatio.getWidth();
int h = aspectRatio.getHeight();
for (Size option : choices) {
if (option.getHeight() == option.getWidth() * h / w &&
option.getWidth() >= width && option.getHeight() >= height) {
bigEnough.add(option);
}
}
// Pick the smallest of those, assuming we found any
if (bigEnough.size() > 0) {
return Collections.min(bigEnough, new CompareSizesByArea());
} else {
Log.e(TAG, "Couldn't find any suitable preview size");
return choices[0];
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_video);
mTextureView = findViewById(R.id.texture);
}
@Override
public void onResume() {
super.onResume();
startBackgroundThread();
if (mTextureView.isAvailable()) {
openCamera(mTextureView.getWidth(), mTextureView.getHeight());
} else {
mTextureView.setSurfaceTextureListener(mSurfaceTextureListener);
}
}
@Override
public void onPause() {
closeCamera();
stopBackgroundThread();
super.onPause();
}
/**
* Starts a background thread and its {@link Handler}.
*/
private void startBackgroundThread() {
mBackgroundThread = new HandlerThread("CameraBackground");
mBackgroundThread.start();
mBackgroundHandler = new Handler(mBackgroundThread.getLooper());
}
/**
* Stops the background thread and its {@link Handler}.
*/
private void stopBackgroundThread() {
mBackgroundThread.quitSafely();
try {
mBackgroundThread.join();
mBackgroundThread = null;
mBackgroundHandler = null;
} catch (InterruptedException e) {
e.printStackTrace();
}
}
/**
* Gets whether you should show UI with rationale for requesting permissions.
*
* @param permissions The permissions your app wants to request.
* @return Whether you can show permission rationale UI.
*/
// private boolean shouldShowRequestPermissionRationale(String[] permissions) {
// for (String permission : permissions) {
// if (FragmentCompat.shouldShowRequestPermissionRationale(this, permission)) {
// return true;
// }
// }
// return false;
// }
/**
* Tries to open a {@link CameraDevice}. The result is listened by `mStateCallback`.
*/
@SuppressWarnings("MissingPermission")
private void openCamera(int width, int height) {
// if (!hasPermissionsGranted(VIDEO_PERMISSIONS)) {
// requestVideoPermissions();
// return;
// }
final Activity activity = this;
if (null == activity || activity.isFinishing()) {
return;
}
CameraManager manager = (CameraManager) activity.getSystemService(Context.CAMERA_SERVICE);
try {
Log.d(TAG, "tryAcquire");
if (!mCameraOpenCloseLock.tryAcquire(2500, TimeUnit.MILLISECONDS)) {
throw new RuntimeException("Time out waiting to lock camera opening.");
}
String cameraId = manager.getCameraIdList()[1];
// Choose the sizes for camera preview and video recording
CameraCharacteristics characteristics = manager.getCameraCharacteristics(cameraId);
StreamConfigurationMap map = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
mSensorOrientation = characteristics.get(CameraCharacteristics.SENSOR_ORIENTATION);
if (map == null) {
throw new RuntimeException("Cannot get available preview/video sizes");
}
mVideoSize = chooseVideoSize(map.getOutputSizes(MediaRecorder.class));
mPreviewSize = chooseOptimalSize(map.getOutputSizes(SurfaceTexture.class),
width, height, mVideoSize);
int orientation = getResources().getConfiguration().orientation;
if (orientation == Configuration.ORIENTATION_LANDSCAPE) {
mTextureView.setAspectRatio(mPreviewSize.getWidth(), mPreviewSize.getHeight());
} else {
mTextureView.setAspectRatio(mPreviewSize.getHeight(), mPreviewSize.getWidth());
}
configureTransform(width, height);
mMediaRecorder = new MediaRecorder();
manager.openCamera(cameraId, mStateCallback, null);
} catch (CameraAccessException e) {
Toast.makeText(activity, "Cannot access the camera.", Toast.LENGTH_SHORT).show();
activity.finish();
} catch (NullPointerException e) {
// Currently an NPE is thrown when the Camera2API is used but not supported on the
// device this code runs.
// Camera2VideoFragment.ErrorDialog.newInstance("cammera error")
// .show(getChildFragmentManager(), FRAGMENT_DIALOG);
} catch (InterruptedException e) {
throw new RuntimeException("Interrupted while trying to lock camera opening.");
}
}
private void closeCamera() {
try {
mCameraOpenCloseLock.acquire();
closePreviewSession();
if (null != mCameraDevice) {
mCameraDevice.close();
mCameraDevice = null;
}
if (null != mMediaRecorder) {
mMediaRecorder.release();
mMediaRecorder = null;
}
} catch (InterruptedException e) {
throw new RuntimeException("Interrupted while trying to lock camera closing.");
} finally {
mCameraOpenCloseLock.release();
}
}
/**
* Start the camera preview.
*/
private void startPreview() {
if (null == mCameraDevice || !mTextureView.isAvailable() || null == mPreviewSize) {
return;
}
try {
closePreviewSession();
SurfaceTexture texture = mTextureView.getSurfaceTexture();
assert texture != null;
texture.setDefaultBufferSize(mPreviewSize.getWidth(), mPreviewSize.getHeight());
mPreviewBuilder = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
Surface previewSurface = new Surface(texture);
mPreviewBuilder.addTarget(previewSurface);
mCameraDevice.createCaptureSession(Collections.singletonList(previewSurface),
new CameraCaptureSession.StateCallback() {
@Override
public void onConfigured(@NonNull CameraCaptureSession session) {
mPreviewSession = session;
updatePreview();
}
@Override
public void onConfigureFailed(@NonNull CameraCaptureSession session) {
Activity activity = VideoActivity.this;
if (null != activity) {
Toast.makeText(VideoActivity.this, "Failed", Toast.LENGTH_SHORT).show();
}
}
}, mBackgroundHandler);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
/**
* Update the camera preview. {@link #startPreview()} needs to be called in advance.
*/
private void updatePreview() {
if (null == mCameraDevice) {
return;
}
try {
setUpCaptureRequestBuilder(mPreviewBuilder);
HandlerThread thread = new HandlerThread("CameraPreview");
thread.start();
mPreviewSession.setRepeatingRequest(mPreviewBuilder.build(), null, mBackgroundHandler);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
private void setUpCaptureRequestBuilder(CaptureRequest.Builder builder) {
builder.set(CaptureRequest.CONTROL_MODE, CameraMetadata.CONTROL_MODE_AUTO);
}
/**
* Configures the necessary {@link android.graphics.Matrix} transformation to `mTextureView`.
* This method should not to be called until the camera preview size is determined in
* openCamera, or until the size of `mTextureView` is fixed.
*
* @param viewWidth The width of `mTextureView`
* @param viewHeight The height of `mTextureView`
*/
private void configureTransform(int viewWidth, int viewHeight) {
Activity activity = VideoActivity.this;
if (null == mTextureView || null == mPreviewSize || null == activity) {
return;
}
int rotation = activity.getWindowManager().getDefaultDisplay().getRotation();
Matrix matrix = new Matrix();
RectF viewRect = new RectF(0, 0, viewWidth, viewHeight);
RectF bufferRect = new RectF(0, 0, mPreviewSize.getHeight(), mPreviewSize.getWidth());
float centerX = viewRect.centerX();
float centerY = viewRect.centerY();
if (Surface.ROTATION_90 == rotation || Surface.ROTATION_270 == rotation) {
bufferRect.offset(centerX - bufferRect.centerX(), centerY - bufferRect.centerY());
matrix.setRectToRect(viewRect, bufferRect, Matrix.ScaleToFit.FILL);
float scale = Math.max(
(float) viewHeight / mPreviewSize.getHeight(),
(float) viewWidth / mPreviewSize.getWidth());
matrix.postScale(scale, scale, centerX, centerY);
matrix.postRotate(90 * (rotation - 2), centerX, centerY);
}
mTextureView.setTransform(matrix);
}
private void setUpMediaRecorder() throws IOException {
final Activity activity = VideoActivity.this;
if (null == activity) {
return;
}
mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.SURFACE);
mMediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
if (mNextVideoAbsolutePath == null || mNextVideoAbsolutePath.isEmpty()) {
mNextVideoAbsolutePath = getVideoFilePath(VideoActivity.this);
}
mMediaRecorder.setOutputFile(mNextVideoAbsolutePath);
mMediaRecorder.setVideoEncodingBitRate(10000000);
mMediaRecorder.setVideoFrameRate(30);
mMediaRecorder.setVideoSize(mVideoSize.getWidth(), mVideoSize.getHeight());
mMediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264);
mMediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AAC);
int rotation = activity.getWindowManager().getDefaultDisplay().getRotation();
switch (mSensorOrientation) {
case SENSOR_ORIENTATION_DEFAULT_DEGREES:
mMediaRecorder.setOrientationHint(DEFAULT_ORIENTATIONS.get(rotation));
break;
case SENSOR_ORIENTATION_INVERSE_DEGREES:
mMediaRecorder.setOrientationHint(INVERSE_ORIENTATIONS.get(rotation));
break;
}
mMediaRecorder.prepare();
}
private String getVideoFilePath(Context context) {
final File dir = context.getExternalFilesDir(null);
return (dir == null ? "" : (dir.getAbsolutePath() + "/"))
+ System.currentTimeMillis() + ".mp4";
}
private void startRecordingVideo() {
if (null == mCameraDevice || !mTextureView.isAvailable() || null == mPreviewSize) {
return;
}
try {
closePreviewSession();
setUpMediaRecorder();
SurfaceTexture texture = mTextureView.getSurfaceTexture();
assert texture != null;
texture.setDefaultBufferSize(mPreviewSize.getWidth(), mPreviewSize.getHeight());
mPreviewBuilder = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_RECORD);
List<Surface> surfaces = new ArrayList<>();
// Set up Surface for the camera preview
Surface previewSurface = new Surface(texture);
surfaces.add(previewSurface);
mPreviewBuilder.addTarget(previewSurface);
// Set up Surface for the MediaRecorder
Surface recorderSurface = mMediaRecorder.getSurface();
surfaces.add(recorderSurface);
mPreviewBuilder.addTarget(recorderSurface);
// Start a capture session
// Once the session starts, we can update the UI and start recording
mCameraDevice.createCaptureSession(surfaces, new CameraCaptureSession.StateCallback() {
@Override
public void onConfigured(@NonNull CameraCaptureSession cameraCaptureSession) {
mPreviewSession = cameraCaptureSession;
updatePreview();
VideoActivity.this.runOnUiThread(new Runnable() {
@Override
public void run() {
// UI
mIsRecordingVideo = true;
// Start recording
mMediaRecorder.start();
}
});
}
@Override
public void onConfigureFailed(@NonNull CameraCaptureSession cameraCaptureSession) {
Activity activity = VideoActivity.this;
if (null != activity) {
Toast.makeText(activity, "Failed", Toast.LENGTH_SHORT).show();
}
}
}, mBackgroundHandler);
} catch (CameraAccessException | IOException e) {
e.printStackTrace();
}
}
private void closePreviewSession() {
if (mPreviewSession != null) {
mPreviewSession.close();
mPreviewSession = null;
}
}
private void stopRecordingVideo() {
// UI
mIsRecordingVideo = false;
// mButtonVideo.setText("record");
// Stop recording
mMediaRecorder.stop();
mMediaRecorder.reset();
Activity activity = VideoActivity.this;
if (null != activity) {
Toast.makeText(activity, "Video saved: " + mNextVideoAbsolutePath,
Toast.LENGTH_SHORT).show();
Log.d(TAG, "Video saved: " + mNextVideoAbsolutePath);
}
mNextVideoAbsolutePath = null;
startPreview();
}
/**
* Compares two {@code Size}s based on their areas.
*/
static class CompareSizesByArea implements Comparator<Size> {
@Override
public int compare(Size lhs, Size rhs) {
// We cast here to ensure the multiplications won't overflow
return Long.signum((long) lhs.getWidth() * lhs.getHeight() -
(long) rhs.getWidth() * rhs.getHeight());
}
}
// public static class ErrorDialog extends DialogFragment {
//
// private static final String ARG_MESSAGE = "message";
//
// public static Camera2VideoFragment.ErrorDialog newInstance(String message) {
// Camera2VideoFragment.ErrorDialog dialog = new Camera2VideoFragment.ErrorDialog();
// Bundle args = new Bundle();
// args.putString(ARG_MESSAGE, message);
// dialog.setArguments(args);
// return dialog;
// }
//
// @Override
// public Dialog onCreateDialog(Bundle savedInstanceState) {
// final Activity activity = getActivity();
// return new AlertDialog.Builder(activity)
// .setMessage(getArguments().getString(ARG_MESSAGE))
// .setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
// @Override
// public void onClick(DialogInterface dialogInterface, int i) {
// activity.finish();
// }
// })
// .create();
// }
//
// }
public void Record(View view)
{
if (mIsRecordingVideo) {
stopRecordingVideo();
} else {
startRecordingVideo();
}
}
}