Android : YUV420 -> RGB Decode 알고리즘 발견

원문 출처 : http://groups.google.com/group/android-developers/msg/d3b29d3ddc8abf9b

// decode Y, U, and V values on the YUV 420 buffer described as YCbCr_422_SP by Android // David Manpearl 081201 public static void decodeYUV(int[] out, byte[] fg, int width, int height) throws NullPointerException, IllegalArgumentException { final 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; } } }