Jak mogę manipulować podglądem kamery?

Użyłem rozwiązania walta , ale miałem pewne problemy z konwersją YUV, rozmiarami wyjściowymi ramek i awarią przy zwolnieniu kamery.

W końcu zadziałał dla mnie następujący kod:

public class MySurfaceView extends SurfaceView implements Callback, Camera.PreviewCallback {

private static final String TAG = "MySurfaceView";

private int width;
private int height;

private SurfaceHolder mHolder;

private Camera mCamera;
private int[] rgbints;

private boolean isPreviewRunning = false; 

private int mMultiplyColor;

public MySurfaceView(Context context, AttributeSet attrs) {
    super(context, attrs);

    mHolder = getHolder();
    mHolder.addCallback(this);
    mMultiplyColor = getResources().getColor(R.color.multiply_color);
}

// @Override
// protected void onDraw(Canvas canvas) {
// Log.w(this.getClass().getName(), "On Draw Called");
// }

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

}

@Override
public void surfaceCreated(SurfaceHolder holder) {
    synchronized (this) {
        if (isPreviewRunning)
            return;

        this.setWillNotDraw(false); // This allows us to make our own draw calls to this canvas


        mCamera = Camera.open();
        isPreviewRunning = true;
        Camera.Parameters p = mCamera.getParameters();
        Size size = p.getPreviewSize();
        width = size.width;
        height = size.height;
        p.setPreviewFormat(ImageFormat.NV21);
        showSupportedCameraFormats(p);
        mCamera.setParameters(p);

        rgbints = new int[width * height];

        // try { mCamera.setPreviewDisplay(holder); } catch (IOException e)
        // { Log.e("Camera", "mCamera.setPreviewDisplay(holder);"); }

        mCamera.startPreview();
        mCamera.setPreviewCallback(this);

    }
}


@Override
public void surfaceDestroyed(SurfaceHolder holder) {
    synchronized (this) {
        try {
            if (mCamera != null) {
                //mHolder.removeCallback(this);
                mCamera.setPreviewCallback(null);
                mCamera.stopPreview();
                isPreviewRunning  = false;
                mCamera.release();
            }
        } catch (Exception e) {
            Log.e("Camera", e.getMessage());
        }
    }
}

@Override
public void onPreviewFrame(byte[] data, Camera camera) {
    // Log.d("Camera", "Got a camera frame");
    if (!isPreviewRunning)
        return;

    Canvas canvas = null;

    if (mHolder == null) {
        return;
    }

    try {
        synchronized (mHolder) {
            canvas = mHolder.lockCanvas(null);
            int canvasWidth = canvas.getWidth();
            int canvasHeight = canvas.getHeight();

            decodeYUV(rgbints, data, width, height);

            // draw the decoded image, centered on canvas
            canvas.drawBitmap(rgbints, 0, width, canvasWidth-((width+canvasWidth)>>1), canvasHeight-((height+canvasHeight)>>1), width, height, false, null);

            // use some color filter
            canvas.drawColor(mMultiplyColor, Mode.MULTIPLY);

        }
    }  catch (Exception e){
        e.printStackTrace();
    } finally {
        // do this in a finally so that if an exception is thrown
        // during the above, we don't leave the Surface in an
        // inconsistent state
        if (canvas != null) {
            mHolder.unlockCanvasAndPost(canvas);
        }
    }
}



/**
 * Decodes YUV frame to a buffer which can be use to create a bitmap. use
 * this for OS < FROYO which has a native YUV decoder decode Y, U, and V
 * values on the YUV 420 buffer described as YCbCr_422_SP by Android
 * 
 * @param rgb
 *            the outgoing array of RGB bytes
 * @param fg
 *            the incoming frame bytes
 * @param width
 *            of source frame
 * @param height
 *            of source frame
 * @throws NullPointerException
 * @throws IllegalArgumentException
 */
public void decodeYUV(int[] out, byte[] fg, int width, int height) throws NullPointerException, IllegalArgumentException {
    int sz = width * height;
    if (out == null)
        throw new NullPointerException("buffer out is null");
    if (out.length < sz)
        throw new IllegalArgumentException("buffer out size " + out.length + " < minimum " + sz);
    if (fg == null)
        throw new NullPointerException("buffer 'fg' is null");
    if (fg.length < sz)
        throw new IllegalArgumentException("buffer fg size " + fg.length + " < minimum " + sz * 3 / 2);
    int i, j;
    int Y, Cr = 0, Cb = 0;
    for (j = 0; j < height; j++) {
        int pixPtr = j * width;
        final int jDiv2 = j >> 1;
    for (i = 0; i < width; i++) {
        Y = fg[pixPtr];
        if (Y < 0)
            Y += 255;
        if ((i & 0x1) != 1) {
            final int cOff = sz + jDiv2 * width + (i >> 1) * 2;
            Cb = fg[cOff];
            if (Cb < 0)
                Cb += 127;
            else
                Cb -= 128;
            Cr = fg[cOff + 1];
            if (Cr < 0)
                Cr += 127;
            else
                Cr -= 128;
        }
        int R = Y + Cr + (Cr >> 2) + (Cr >> 3) + (Cr >> 5);
        if (R < 0)
            R = 0;
        else if (R > 255)
            R = 255;
        int G = Y - (Cb >> 2) + (Cb >> 4) + (Cb >> 5) - (Cr >> 1) + (Cr >> 3) + (Cr >> 4) + (Cr >> 5);
        if (G < 0)
            G = 0;
        else if (G > 255)
            G = 255;
        int B = Y + Cb + (Cb >> 1) + (Cb >> 2) + (Cb >> 6);
        if (B < 0)
            B = 0;
        else if (B > 255)
            B = 255;
        out[pixPtr++] = 0xff000000 + (B << 16) + (G << 8) + R;
    }
    }

}

private void showSupportedCameraFormats(Parameters p) {
    List<Integer> supportedPictureFormats = p.getSupportedPreviewFormats();
    Log.d(TAG, "preview format:" + cameraFormatIntToString(p.getPreviewFormat()));
    for (Integer x : supportedPictureFormats) {
        Log.d(TAG, "suppoterd format: " + cameraFormatIntToString(x.intValue()));
    }

}

private String cameraFormatIntToString(int format) {
    switch (format) {
    case PixelFormat.JPEG:
        return "JPEG";
    case PixelFormat.YCbCr_420_SP:
        return "NV21";
    case PixelFormat.YCbCr_422_I:
        return "YUY2";
    case PixelFormat.YCbCr_422_SP:
        return "NV16";
    case PixelFormat.RGB_565:
        return "RGB_565";
    default:
        return "Unknown:" + format;

        }
    }
}

Aby go użyć, Uruchom z Twojej aktywności onCreate następujący kod:

            SurfaceView surfaceView = new MySurfaceView(this, null);
        RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.MATCH_PARENT);
        surfaceView.setLayoutParams(layoutParams);
        mRelativeLayout.addView(surfaceView);

Patrzyłeś na GPUImage ?

Pierwotnie była to biblioteka OSX/iOS stworzona przez Brada Larsona, która istnieje jako Objective-C wrapper wokół OpenGL / ES.

Https://github.com/BradLarson/GPUImage

Ludzie z CyberAgent stworzyli Port Androida (który nie ma pełnego parzystości funkcji), który jest zestawem owijarek Javy na OpenGLES. Jest stosunkowo wysoki poziom i dość łatwy do wdrożenia, z wieloma wymienionymi funkcjami powyżej...

Https://github.com/CyberAgent/android-gpuimage