我正在尝试制作自定义视频应用。我只使用清单 2.2（API 8）中的设置。
一切顺利，但我不明白为什么肖像模式视频与lanscape视频没有区别。
为了检测设备更改的方向，我在surfaceChanged（）
中使用此代码 if (mCamera != null) {
Camera.Parameters p = mCamera.getParameters();
try {
mCamera.stopPreview();
} catch (Exception e) {
// TODO: handle exception
}
int previewWidth = 0;
int previewHeight = 0;
if (mPreviewSize != null) {
Display display = ((WindowManager) mContext.getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
int rotation = display.getRotation();
switch (rotation) {
case Surface.ROTATION_0:
previewWidth = mPreviewSize.height;
previewHeight = mPreviewSize.width;
mCamera.setDisplayOrientation(90);
break;
case Surface.ROTATION_90:
previewWidth = mPreviewSize.width;
previewHeight = mPreviewSize.height;
mCamera.setDisplayOrientation(0);
break;
case Surface.ROTATION_180:
previewWidth = mPreviewSize.height;
previewHeight = mPreviewSize.width;
mCamera.setDisplayOrientation(270);
break;
case Surface.ROTATION_270:
previewWidth = mPreviewSize.width;
previewHeight = mPreviewSize.height;
mCamera.setDisplayOrientation(180);
break;
}
p.setPreviewSize(previewWidth, previewHeight);
mCamera.setParameters(p);
}
try {
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
} catch (Exception e) {
Log.d(TAG, "Cannot start preview.", e);
}
}
像魅力一样工作。如果我旋转设备表面更改方向，请调用surfaceChanged，其中camera设置为适当的DisplayRotation。
问题是如何确定视频是以景观模式还是以纵向模式捕获的。因为我得到的所有视频都是横向拍摄的。它不依赖于setDisplayOrientation，它只影响预览过程。
同时探索这个问题我注意到如果要使用标准相机应用程序，它会将特殊标签写入视频文件（在MediaInfo中看到）：旋转：90 用于拍摄肖像。
但是MediaRecorder类没有。
似乎是问题所在。有人要解决这个问题吗？
答案 0 :(得分：28)
camera.setDisplayOrientation(90);
要旋转预览，请
recorder.setOrientationHint(90);
要将视频标记为旋转90°，手机会在阅读时自动旋转。
所以你要做的就是
camera = Camera.open();
//Set preview with a 90° ortientation
camera.setDisplayOrientation(90);
camera.unlock();
holder = getHolder();
holder.addCallback(this);
holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
recorder = new MediaRecorder();
recorder.setCamera(camera);
recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
recorder.setVideoSource(MediaRecorder.VideoSource.DEFAULT);
recorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
recorder.setVideoEncoder(MediaRecorder.VideoEncoder.MPEG_4_SP);
recorder.setOutputFile(getVideoFolder()+rnd.nextString()+".mp4");
recorder.setPreviewDisplay(holder.getSurface());
//Tags the video with a 90° angle in order to tell the phone how to display it
recorder.setOrientationHint(90);
if (recorder != null) {
try {
recorder.prepare();
} catch (IllegalStateException e) {
Log.e("IllegalStateException", e.toString());
} catch (IOException e) {
Log.e("IOException", e.toString());
}
}
recorder.start();
希望它有所帮助; - ）
答案 1 :(得分：7)
camera.setDisplayOrientation（90）无法在所有设备中使用。以下解决方案在不同设备中完美地工作，并且还处理棉花糖运行时许可。
参见setCameraRotation方法
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
private SurfaceHolder mHolder;
private Camera mCamera;
public static int rotate;
private Context mContext;
public CameraPreview(Context context, Camera camera) {
super(context);
mCamera = camera;
mHolder = getHolder();
mHolder.addCallback(this);
// deprecated setting, but required on Android versions prior to 3.0
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
mContext = context;
}
public void surfaceCreated(SurfaceHolder holder) {
try {
// create the surface and start camera preview
if (mCamera != null) {
mCamera.setPreviewDisplay(holder);
mCamera.startPreview();
}
} catch (IOException e) {
Log.d(VIEW_LOG_TAG, "Error setting camera preview: " + e.getMessage());
}
}
public void refreshCamera(Camera camera) {
if (mHolder.getSurface() == null) {
// preview surface does not exist
return;
}
// stop preview before making changes
stopPreview();
// set preview size and make any resize, rotate or
// reformatting changes here
setCamera(camera);
// start preview with new settings
startPreview();
}
public void stopPreview(){
try {
if(mCamera != null)
mCamera.stopPreview();
} catch (Exception e) {
// ignore: tried to stop a non-existent preview
e.printStackTrace();
}
}
public void startPreview(){
try {
if(mCamera != null) {
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
}else{
Log.d(VIEW_LOG_TAG, "Error starting camera preview: " );
}
} catch (Exception e) {
Log.d(VIEW_LOG_TAG, "Error starting camera preview: " + e.getMessage());
}
}
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
// If your preview can change or rotate, take care of those events here.
// Make sure to stop the preview before resizing or reformatting it.
refreshCamera(mCamera);
}
public void setCamera(Camera camera) {
//method to set a camera instance
mCamera = camera;
/**
* add camera orientation and display rotation according to screen landscape or portrait
*/
setCameraRotation();
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
// TODO Auto-generated method stub
if(mCamera != null){
mCamera.release();
}
}
public void setCameraRotation() {
try {
Camera.CameraInfo camInfo = new Camera.CameraInfo();
if (VideoCaptureActivity.cameraId == 0)
Camera.getCameraInfo(Camera.CameraInfo.CAMERA_FACING_BACK, camInfo);
else
Camera.getCameraInfo(Camera.CameraInfo.CAMERA_FACING_FRONT, camInfo);
int cameraRotationOffset = camInfo.orientation;
// ...
Camera.Parameters parameters = mCamera.getParameters();
int rotation = ((Activity)mContext).getWindowManager().getDefaultDisplay().getRotation();
int degrees = 0;
switch (rotation) {
case Surface.ROTATION_0:
degrees = 0;
break; // Natural orientation
case Surface.ROTATION_90:
degrees = 90;
break; // Landscape left
case Surface.ROTATION_180:
degrees = 180;
break;// Upside down
case Surface.ROTATION_270:
degrees = 270;
break;// Landscape right
}
int displayRotation;
if (camInfo.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
displayRotation = (cameraRotationOffset + degrees) % 360;
displayRotation = (360 - displayRotation) % 360; // compensate
// the
// mirror
} else { // back-facing
displayRotation = (cameraRotationOffset - degrees + 360) % 360;
}
mCamera.setDisplayOrientation(displayRotation);
if (camInfo.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
rotate = (360 + cameraRotationOffset + degrees) % 360;
} else {
rotate = (360 + cameraRotationOffset - degrees) % 360;
}
parameters.set("orientation", "portrait");
parameters.setRotation(rotate);
mCamera.setParameters(parameters);
} catch (Exception e) {
}
}
}
现在准备好正确旋转的录像机，以便录制的视频以正确的方向播放。
mediaRecorder.setOrientationHint（CameraPreview.rotate）;
private boolean prepareMediaRecorder（）{
mediaRecorder = new MediaRecorder();
mCamera.unlock();
mediaRecorder.setCamera(mCamera);
mediaRecorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);
mediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
mediaRecorder.setOrientationHint(CameraPreview.rotate);
mediaRecorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_LOW));
mediaRecorder.setOutputFile(filePath);
mediaRecorder.setMaxDuration(15000); // Set max duration 15 sec.
mediaRecorder.setMaxFileSize(10000000); // Set max file size 1M
try {
mediaRecorder.prepare();
} catch (IllegalStateException e) {
releaseMediaRecorder();
return false;
} catch (IOException e) {
releaseMediaRecorder();
return false;
}
return true;
}
您可以下载完整的示例https://github.com/umesh-kushwaha/Android_Video_Recording_portrait