Question

Android Camera提取出来的yuv源数据怎么提取y，u，v分量

Answer 1

Android
camera采集到的可以是yuv420sp也可以食yuv420p。我知道yuv420中yuv的分布。现在主要有个前提是从Android
Camera
中采集到的yuv420数据，这个byte[]的长度是一倍的视频宽高乘积，不是1.5倍。在jni里面获取到的长度又确实是1.5倍，但是在jni里面转换为jbyte*
的长度还是1倍，就不知道怎么弄了~
查看原帖>>

Answer 2

Camera默认的预览格式是 NV21，4:2:0 结构的，每个U、V用于4个Y
参考下下面的代码
**
* Converts YUV420 NV21 to ARGB8888
*
* @param data byte array on YUV420 NV21 format.
* @param width pixels width
* @param height pixels height
* @retur a ARGB8888 pixels int array. Where each int is a pixels ARGB.
*/
public static int[] convertYUV420_NV21toARGB8888(byte [] data, int width, int height) {
int size = width*height;
int offset = size;
int[] pixels = new int[size];
int u, v, y1, y2, y3, y4;

// i along Y and the final pixels
// k along pixels U and V
for(int i=0, k=0; i < size; i+=2, k+=1) {
y1 = data[i ]&0xff;
y2 = data[i+1]&0xff;
y3 = data[width+i ]&0xff;
y4 = data[width+i+1]&0xff;

v = data[offset+k ]&0xff;
u = data[offset+k+1]&0xff;
v = v-128;
u = u-128;

pixels[i ] = convertYUVtoARGB(y1, u, v);
pixels[i+1] = convertYUVtoARGB(y2, u, v);
pixels[width+i ] = convertYUVtoARGB(y3, u, v);
pixels[width+i+1] = convertYUVtoARGB(y4, u, v);

if (i!=0 && (i+2)%width==0)
i+=width;
}

return pixels;
}

private static int convertYUVtoARGB(int y, int u, int v) {
int r,g,b;

r = y + (int)(1.402f*u);
g = y - (int)(0.344f*v + 0.714f*u);
b = y + (int)(1.772f*v);
r = r>255? 255 : r<0 ? 0 : r;
g = g>255? 255 : g<0 ? 0 : g;
b = b>255? 255 : b<0 ? 0 : b;
return 0xff000000 | (r<<16) | (g<<8) | b;
}