Android MediaRecoder сохраняет пустой файл - PullRequest
7 голосов
/ 11 марта 2012

Это код, который я использовал для записи видео с устройства Android в формате MP4.Файл создается, но имеет размер 0 байт.Кажется, я не понимаю, что пошло не так.Любая помощь будет оценена.

                if(mCamera == null) {
        mCamera = Camera.open();
        mCamera.unlock();
    }

    if(mediaRecorder == null)
        mediaRecorder = new MediaRecorder();


    mediaRecorder.setCamera(mCamera);

    mediaRecorder.setCamera(mCamera);
    mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
    mediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);

    mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);

    mediaRecorder.setMaxDuration(maxDurationInMs);


    mediaRecorder.setOutputFile("/sdcard/1.mp4");

    mediaRecorder.setVideoFrameRate(videoFramesPerSecond);
    mediaRecorder.setVideoSize(176,144);

    mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.DEFAULT);
    mediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.MPEG_4_SP);

    mediaRecorder.setPreviewDisplay(surface);

    mediaRecorder.setMaxFileSize(maxFileSizeInBytes);

                mediaRecorder.prepare();        
    try {
        mediaRecorder.prepare();
    } catch (IllegalStateException e) {
        // This is thrown if the previous calls are not called with the 
        // proper order
        e.printStackTrace();
    }

            mediaRecorder.start();

Ответы [ 5 ]

9 голосов
/ 10 июля 2013

Причиной такого поведения является то, что вы (наверняка на 95%) звоните recorder.setOutputFile() снова после , когда вы закончили запись (возможно, после recorder.stop()).Таким образом старый файл переписывается новым пустым файлом.

4 голосов
/ 12 марта 2012

хорошо, так что я наконец-то понял это сам.Я использовал метод, описанный здесь, и он работал правильно.

http://developer.android.com/guide/topics/media/camera.html#saving-media

2 голосов
/ 29 января 2018

Ниже у меня работает код:

 private boolean isRecording = false;

public static final int MEDIA_TYPE_IMAGE = 1;
public static final int MEDIA_TYPE_VIDEO = 2;

 @Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_video_record);

    // Create an instance of Camera
    mCamera = getCameraInstance();

    mHolder = surfaceViewRecReadyTestimonial.getHolder();
    mHolder.addCallback(this);
    mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}


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
}

 private boolean prepareVideoRecorder() {

    mCamera = getCameraInstance();
    mMediaRecorder = new MediaRecorder();

    // Step 1: Unlock and set camera to MediaRecorder
    mCamera.unlock();
    mMediaRecorder.setCamera(mCamera);

    // Step 2: Set sources
    mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);
    mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);

    // Step 3: Set a CamcorderProfile (requires API Level 8 or higher)
    mMediaRecorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_HIGH));

    // Step 4: Set output file
    mMediaRecorder.setOutputFile(getOutputMediaFile(MEDIA_TYPE_VIDEO).toString());

    // Step 5: Set the preview output
    mMediaRecorder.setPreviewDisplay(surfaceViewRecReadyTestimonial.getHolder().getSurface());

    // Step 6: Prepare configured MediaRecorder
    try {
        mMediaRecorder.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;
} 

 @Override
public void onClick(View v) {

    if (v == btnStart) {

            // initialize video camera
            if (prepareVideoRecorder()) {
                // Camera is available and unlocked, MediaRecorder is prepared,
                // now you can start recording
                mMediaRecorder.start();

                // inform the user that recording has started
                isRecording = true;
            } else {
                // prepare didn't work, release the camera
                releaseMediaRecorder();
                // inform user
            }


        } else if (v == btnStop) {

            if (isRecording) {
                // stop recording and release camera
                mMediaRecorder.stop();  // stop the recording
                releaseMediaRecorder(); // release the MediaRecorder object
                mCamera.lock();         // take camera access back from MediaRecorder

                // inform the user that recording has stopped
                isRecording = false;
            }

        } }

private void releaseMediaRecorder() {
    if (mMediaRecorder != null) {
        mMediaRecorder.reset();   // clear recorder configuration
        mMediaRecorder.release(); // release the recorder object
        mMediaRecorder = null;
        mCamera.lock();           // lock camera for later use
    }
}

 private void releaseCamera() {
    if (mCamera != null) {
        mCamera.release();        // release the camera for other applications
        mCamera = null;
    }
}

/**
 * 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), "FolderName");
    // 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("FolderName", "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");
    } else {
        return null;
    }

    return mediaFile;
}

 @Override
protected void onPause() {
    super.onPause();

    releaseMediaRecorder();       // if you are using MediaRecorder, release it first
    releaseCamera();              // release the camera immediately on pause event

}

@Override
public void surfaceCreated(SurfaceHolder holder) {
    // The Surface has been created, now tell the camera where to draw the preview.
    try {
        mCamera.setPreviewDisplay(holder);
        mCamera.startPreview();
    } catch (IOException e) {
        Log.d("RecordVideo", "Error setting camera preview: " + e.getMessage());
    }
}

@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

    // If your preview can change or rotate, take care of those events here.
    // Make sure to stop the preview before resizing or reformatting it.

    if (mHolder.getSurface() == null) {
        // preview surface does not exist
        return;
    }

    // stop preview before making changes
    try {
        mCamera.stopPreview();
    } catch (Exception e) {
        // ignore: tried to stop a non-existent preview
    }

    try {
        Camera.Parameters parameters = mCamera.getParameters();

        Display display = ((WindowManager) getSystemService(WINDOW_SERVICE)).getDefaultDisplay();

        if (display.getRotation() == Surface.ROTATION_0) {
            parameters.setPreviewSize(height, width);
            mCamera.setDisplayOrientation(90);
        }

        if (display.getRotation() == Surface.ROTATION_90) {
            parameters.setPreviewSize(width, height);
        }

        if (display.getRotation() == Surface.ROTATION_180) {
            parameters.setPreviewSize(height, width);
        }

        if (display.getRotation() == Surface.ROTATION_270) {
            parameters.setPreviewSize(width, height);
            mCamera.setDisplayOrientation(180);
        }

        if (mCamera != null) {
            try {
                mCamera.setPreviewDisplay(mHolder);
                mCamera.startPreview();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    } catch (Exception e) {
        e.printStackTrace();
    }

    // set preview size and make any resize, rotate or
    // reformatting changes here

    // start preview with new settings
    try {
        mCamera.setPreviewDisplay(mHolder);
        mCamera.startPreview();

    } catch (Exception e) {
        Log.d(TAG, "Error starting camera preview: " + e.getMessage());
    }

}

@Override
public void surfaceDestroyed(SurfaceHolder holder) {

}
0 голосов
/ 25 сентября 2014

У вас установлено разрешение пользователя

<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.RECORD_AUDIO" /> 
0 голосов
/ 11 марта 2012
public static final String rootDir = getStorageDir().concat(yours_dir);
...
mediaRecorder.setOutputFile(rootDir);
...