Photos captured from Android camera are completely black

Question

I make a camera and try to capture a picture. Since the original data is YUV, I turn it into RGB using function:

static public void decodeYUV420SP(byte[] rgbBuf, byte[] yuv420sp,int width, int height)

However, the photo saved is completely black, there is no content in it.

I also found the following way:

mBitmap = BitmapFactory.decodeByteArray(data, 0, data.length);

but the project was shut down.

Are there any other effective ways to save a photo? Thank you!

Answer 1

An old post, but it speaks of a similar problem that I have so I might as well answer the part I know :)

You're probably doing it wrong. I suggest you use the JPEG callback to store the image:

mCamera.takePicture(null, null, callbackJPEG);

This way you will get JPEG data into the routine which you can store into a file unmodified:

final Camera.PictureCallback mCall = new Camera.PictureCallback()
{
  @Override
  public void onPictureTaken(byte[] data, Camera camera)
  {
    //Needs <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    File sdCard = Environment.getExternalStorageDirectory();
    File file = new File(sdCard, "pic.jpg");
    fil = new FileOutputStream(file);
    fil.write(data);
    fil.close();          
  }
}

As far as the black picture goes, I have found that placing a simple Thread.sleep(250) between camera.startPreview() and camera.takePicture() takes care of that particular problem on my Galaxy Nexus. I have no idea why this delay is necessary. Even if I add camera.setOneShotPreviewCallback() and call camera.takePicture() from the callback, the image comes out black if I don't first delay... Oh, and the delay is not just "some" delay. It has to be some pretty long value. For example, 250ms sometimes works, sometimes not on my phone.