如何使用相机API更改自定义摄像机原始数据?

时间:2019-02-28 08:56:06

标签: java android video filtering recording

我是android的新手,现在我正在尝试制作自定义相机应用。我可以制作自定义相机并拍摄一些视频。但是未能更改相机原始数据。我想在相机上添加黑白等实时滤镜。我使用此方法更改了数据

final Camera.PreviewCallback callback = new Camera.PreviewCallback() {
    @Override
    public void onPreviewFrame(byte[] data, Camera camera) {
        //Do your processing here... Use the byte[] called "data"
        int pixelCount = width * height;
        int[] out = new int[pixelCount];
        for (int i = 0; i < pixelCount; ++i) {
            int luminance = data[i] & 0xFF;
            out[i] = Color.argb(0xFF, luminance, luminance, luminance);
            data[i] = (byte) out[i];
        }
    }
};
mCamera.setPreviewCallback(callback);

但是没有用。对于何时应调用mCamera.setPreviewCallback(callback)方法,我也感到困惑。

为了更好地理解,我在这里给出了完整的代码。

Mainactivity.java

package com.example.msi.magiccamera;

import android.content.Context;
import android.graphics.Color;
import android.hardware.Camera;

import android.media.CamcorderProfile;
import android.media.MediaRecorder;
import android.net.Uri;
import android.os.Environment;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.Button;
import android.widget.FrameLayout;
import android.widget.Toast;

import java.io.File;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;

import static android.content.ContentValues.TAG;

public class MainActivity extends AppCompatActivity {

    private Camera mCamera;
    private CameraPreview mPreview;
    private MediaRecorder mediaRecorder;
    public static final int MEDIA_TYPE_IMAGE = 1;
    public static final int MEDIA_TYPE_VIDEO = 2;
    private boolean isRecording = false;
    private SurfaceHolder mholder;
    private Button captureButton;

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


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

        // Create our Preview view and set it as the content of our activity.
        mPreview = new CameraPreview(this, mCamera);
        FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);

        DisplayMetrics displayMetrics = new DisplayMetrics();
        getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
        final int height = displayMetrics.heightPixels;
        final int width = displayMetrics.widthPixels;


        preview.addView(mPreview);

        mholder = mPreview.getHolder();
        mPreview.surfaceCreated(mholder);

        final Camera.PreviewCallback callback = new Camera.PreviewCallback() {
            @Override
            public void onPreviewFrame(byte[] data, Camera camera) {
                //Do your processing here... Use the byte[] called "data"
                int pixelCount = width * height;
                int[] out = new int[pixelCount];
                for (int i = 0; i < pixelCount; ++i) {
                    int luminance = data[i] & 0xFF;
                    out[i] = Color.argb(0xFF, luminance, luminance, luminance);
                    data[i] = (byte) out[i];
                }
            }
        };
        //mCamera.setPreviewCallback(callback);



        captureButton =  findViewById(R.id.captureButton);
        captureButton.setOnClickListener(
                new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        if (isRecording) {
                            // stop recording and release camera
                            mediaRecorder.stop();  // stop the recording
                            releaseMediaRecorder(); // release the MediaRecorder object
                            mCamera.lock();         // take camera access back from MediaRecorder

                            // inform the user that recording has stopped
                            //setCaptureButtonText("Capture");
                            captureButton.setText("Capture");
                            isRecording = false;
                        } else {
                            // initialize video camera
                            if (prepareVideoRecorder()) {

                                // Camera is available and unlocked, MediaRecorder is prepared,
                                // now you can start recording
                                mediaRecorder.start()   ;
                                //mCamera.setPreviewCallback(callback);
                                // inform the user that recording has started
                                //setCaptureButtonText("Stop");
                                captureButton.setText("Stop");
                                isRecording = true;
                            } else {
                                // prepare didn't work, release the camera
                                releaseMediaRecorder();
                                // inform user
                            }
                        }
                    }

                    private void setCaptureButtonText(String capture) {
                    }
                }
        );        
    }

    /** A safe way to get an instance of the Camera object. */
    public static android.hardware.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();
        mediaRecorder = new MediaRecorder();


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


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

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

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

        // Step 5: Set the preview output
        mediaRecorder.setPreviewDisplay(mPreview.getHolder().getSurface());

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


    /** 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_PICTURES), "MyCameraApp");
        // 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");
        } 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
    }

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

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

Camerapreview.java

package com.example.msi.magiccamera;

import android.content.Context;
import android.graphics.Color;
import android.hardware.Camera;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.WindowManager;

import java.io.IOException;

import static android.content.ContentValues.TAG;

/** A basic Camera preview class */
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
    private SurfaceHolder mHolder;
    private Camera mCamera;

    //New codes


    @Override
    public SurfaceHolder getHolder() {
        return super.getHolder();
    }

    public CameraPreview(Context context, Camera camera) {
        super(context);
        mCamera = camera;

        // Install a SurfaceHolder.Callback so we get notified when the
        // underlying surface is created and destroyed.
        mHolder = getHolder();
        mHolder.addCallback(this);
        // deprecated setting, but required on Android versions prior to 3.0
        mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    }

    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(TAG, "Error setting camera preview: " + e.getMessage());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void surfaceDestroyed(SurfaceHolder holder) {
        // empty. Take care of releasing the Camera preview in your activity.
    }

    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.

        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
        }

        // 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());
        }
    }
}

0 个答案:

没有答案