我正在制作相机应用程序而且我有问题，我无法设置视频的帧速率，我的代码看起来像这样 我将帧速率设置为30，但它忽略它并且它在15中记录，我知道在某些设备上它没有设置实际帧速率而是建议的帧速率，并且手机根据照明决定，但是我记录了外面的光线，它仍然以低fps录制，可能我做错了
MediaRecorder recorder;
Camera camera;
SurfaceView preview;
SurfaceHolder holder;
boolean isRecording = false;
String TAG = "Evolution Camera";
int frameRate = 30;
public static final int MEDIA_TYPE_IMAGE = 1;
public static final int MEDIA_TYPE_VIDEO = 2;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
setContentView(R.layout.camera_view);
preview = (SurfaceView) findViewById(R.id.camera_preview);
// Add a listener to the Capture button
ImageButton captureButton = (ImageButton) findViewById(R.id.btn_capture);
captureButton.setOnClickListener(
new View.OnClickListener() {
@Override
public void onClick(View v) {
record();
}
}
);
}
private boolean prepareVideoRecorder(){
camera = getCameraInstance();
recorder = new MediaRecorder();
// Step 1: Unlock and set camera to MediaRecorder
camera.unlock();
recorder.setCamera(camera);
// Step 2: Set sources
recorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);
recorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
// Step 3: Set a CamcorderProfile (requires API Level 8 or higher)
recorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_HIGH));
recorder.setVideoFrameRate(frameRate);
// Step 4: Set output file
recorder.setOutputFile(getOutputMediaFile(MEDIA_TYPE_VIDEO).toString());
// Step 5: Set the preview output
recorder.setPreviewDisplay(preview .getHolder().getSurface());
// Step 6: Prepare configured MediaRecorder
try {
recorder.prepare();
} catch (IllegalStateException e) {
Log.d(TAG, "IllegalStateException preparing MediaRecorder: " + e.getMessage());
releaseMediaRecorder();
return false;
} catch (IOException e) {
Log.d(TAG, "IOException preparing MediaRecorder: " + e.getMessage());
releaseMediaRecorder();
return false;
}
return true;
}
void record()
{
if (isRecording) {
// stop recording and release camera
recorder.stop(); // stop the recording
releaseMediaRecorder(); // release the MediaRecorder object
camera.lock(); // take camera access back from MediaRecorder
// inform the user that recording has stopped
//setCaptureButtonText("Capture");
isRecording = false;
} else {
// initialize video camera
if (prepareVideoRecorder()) {
// Camera is available and unlocked, MediaRecorder is prepared,
// now you can start recording
recorder.start();
setParameters();
// inform the user that recording has started
//setCaptureButtonText("Stop");
isRecording = true;
} else {
// prepare didn't work, release the camera
releaseMediaRecorder();
// inform user
}
}
}
void setParameters()
{
// set Camera parameters
Camera.Parameters params = camera.getParameters();
if (params.getMaxNumMeteringAreas() > 0){ // check that metering areas are supported
List<Camera.Area> meteringAreas = new ArrayList<Camera.Area>();
Rect areaRect1 = new Rect(-100, -100, 100, 100); // specify an area in center of image
meteringAreas.add(new Camera.Area(areaRect1, 600)); // set weight to 60%
Rect areaRect2 = new Rect(800, -1000, 1000, -800); // specify an area in upper right of image
meteringAreas.add(new Camera.Area(areaRect2, 400)); // set weight to 40%
params.setMeteringAreas(meteringAreas);
}
params.setFocusMode(Camera.Parameters.FOCUS_MODE_INFINITY);
camera.setParameters(params);
}
@Override
protected void onPause() {
super.onPause();
if (isRecording) {
recorder.stop(); // stop the recording
releaseMediaRecorder(); // release the MediaRecorder object
camera.lock();
isRecording = false;
}
else {
releaseMediaRecorder();
}
releaseCamera();
}
private void releaseMediaRecorder(){
if (recorder != null) {
recorder.reset(); // clear recorder configuration
recorder.release(); // release the recorder object
recorder = null;
camera.lock(); // lock camera for later use
}
}
private void releaseCamera(){
if (camera != null){
camera.release(); // release the camera for other applications
camera = null;
}
}
/** Create a file Uri for saving an image or video */
private static Uri getOutputMediaFileUri(int type){
return Uri.fromFile(getOutputMediaFile(type));
}
/** Create a File for saving an image or video */
private static File getOutputMediaFile(int type){
// To be safe, you should check that the SDCard is mounted
// using Environment.getExternalStorageState() before doing this.
File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_DCIM), "Evolution");
// This location works best if you want the created images to be shared
// between applications and persist after your app has been uninstalled.
// Create the storage directory if it does not exist
if (! mediaStorageDir.exists()){
if (! mediaStorageDir.mkdirs()){
Log.d("MyCameraApp", "failed to create directory");
return null;
}
}
// Create a media file name
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
File mediaFile;
if (type == MEDIA_TYPE_IMAGE){
mediaFile = new File(mediaStorageDir.getPath() + File.separator +
"IMG_"+ timeStamp + ".jpg");
} else if(type == MEDIA_TYPE_VIDEO) {
mediaFile = new File(mediaStorageDir.getPath() + File.separator +
"VID_"+ timeStamp + ".mp4");
Log.d("MyCameraApp", "File created "+ mediaStorageDir.getPath().toString());
} else {
return null;
}
return mediaFile;
}
public static Camera getCameraInstance(){
Camera c = null;
try {
c = Camera.open(); // attempt to get a Camera instance
}
catch (Exception e){
// Camera is not available (in use or does not exist)
}
return c; // returns null if camera is unavailable
}
@Override
public void onPreviewFrame(byte[] data, Camera camera) {
// TODO Auto-generated method stub
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
// TODO Auto-generated method stub
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
// TODO Auto-generated method stub
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
// TODO Auto-generated method stub
if (isRecording) {
recorder.stop();
isRecording = false;
}
recorder.release();
}
默认的相机应用程序在相同条件下以24 fps记录
答案 0 :(得分：5)
我用这个解决了它
Camera.Parameters params = camera.getParameters();
params.setPreviewFpsRange(24000, 30000);
camera.setParameters(params);
现在我得到22-23 fps（我猜是因为现在是晚上）
答案 1 :(得分：0)
取决于自动曝光参数。在所有照明条件下使用固定帧速率（来自API 14，Android 4.0）：
Camera.Parameters p = camera.getParameters();
p.setPreviewFpsRange( 30000, 30000 ); // 30 fps
if ( p.isAutoExposureLockSupported() )
p.setAutoExposureLock( true );
camera.setParameters( p );