Part 1:
Because the camera Preview Data in android can only be in the imageformat. nv21 format, decoding should go through a twists and turns.
Camera mcamera = camera. open (); camera. parameters P = mcamera. getparameters (); p. setpreviewformat (imageformat. nv21);/* This is a unique value and can be left unspecified. Some users may set a value below pixelformat, which is actually incorrect. For details, refer to the official documentation */
mCamera.setParameters(p);mCamera.startPreview();
Method 1: built-in decoding method of system sdk2.2
@Override public void onPreviewFrame(byte[] data, Camera camera) { Size size = camera.getParameters().getPreviewSize(); try{ YuvImage image = new YuvImage(data, ImageFormat.NV21, size.width, size.height, null); if(image!=null){ ByteArrayOutputStream stream = new ByteArrayOutputStream(); image.compressToJpeg(new Rect(0, 0, size.width, size.height), 80, stream); Bitmap bmp = BitmapFactory.decodeByteArray(stream.toByteArray(), 0, stream.size()); stream.close(); } }catch(Exception ex){ Log.e("Sys","Error:"+ex.getMessage()); } }
The code is simple. Convert YUV data to bitmap. The system provides the yuvimage class.
Method 2: manual Decoding
public Bitmap rawByteArray2RGBABitmap2(byte[] data, int width, int height) { int frameSize = width * height; int[] rgba = new int[frameSize]; for (int i = 0; i < height; i++) for (int j = 0; j < width; j++) { int y = (0xff & ((int) data[i * width + j])); int u = (0xff & ((int) data[frameSize + (i >> 1) * width + (j & ~1) + 0])); int v = (0xff & ((int) data[frameSize + (i >> 1) * width + (j & ~1) + 1])); y = y < 16 ? 16 : y; int r = Math.round(1.164f * (y - 16) + 1.596f * (v - 128)); int g = Math.round(1.164f * (y - 16) - 0.813f * (v - 128) - 0.391f * (u - 128)); int b = Math.round(1.164f * (y - 16) + 2.018f * (u - 128)); r = r < 0 ? 0 : (r > 255 ? 255 : r); g = g < 0 ? 0 : (g > 255 ? 255 : g); b = b < 0 ? 0 : (b > 255 ? 255 : b); rgba[i * width + j] = 0xff000000 + (b << 16) + (g << 8) + r; } Bitmap bmp = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888); bmp.setPixels(rgba, 0 , width, 0, 0, width, height); return bmp; }