yuv数据裁剪

yuv数据裁剪。
int crop_yuv420_area(unsigned char *pInBuf, unsigned int width, unsigned int height, unsigned char *pOutBuf, int new_x, int new_y, int new_width, int new_height)
{
 if(NULL == pInBuf || 0 == width || 0 == height)
 return -1;


 int length = new_width* new_height* 3 / 2;


 memset(pOutBuf , 0, length);


 unsigned char *pUBuf = pOutBuf + new_width * new_height;
 unsigned char *pVBuf = pOutBuf +new_width * new_height * 5 / 4;
 int x = 0,y = 0;
 for(x = 0; x < new_width; x++)
 {
 for (y = 0; y < new_height; y++) //每个循环写一列
 {
 *(pOutBuf + y * new_width + x) = *(pInBuf + (x + new_x) + width * (y + new_y)); //cope Y
 if (1 == (x + new_x)%2 && 1 == (y + new_y)%2)
 {
 long pix = width * height + (width>>1) * ((y + new_y)>>1) + (((x + new_x))>>1);
 *(pUBuf + (new_width/2)*(y/2) + x/2) = *(pInBuf + pix); //cope U


 pix += width * height / 4;
 *(pVBuf + (new_width/2)*(y/2) + x/2) = *(pInBuf + pix); //cope V
 }
 }
 }
 return 0;
}

转成黑白图像，然后，把黑色或白色部份填充其它颜色

int amplify3(unsigned char* p)
{
    unsigned char v = *p;
    if(v > 128)
    {
        *p = 0;

    }
    else
    {
        *p = 255;
    }
    return *p;

}

int read_write_one_frame(char* buff,int framelen,FILE* in,FILE* out)
{
    int n = 0,i,j;
    char* p = NULL;

    memset(buff + framelen*2/3 , 128, framelen / 3);
    p = buff;
    char* pcb = buff + framelen*2/3;
    char* pcr = buff + framelen*2/3 + framelen / 6;
   // for(i = 0; i < framelen*2/3; i++)
    for(i = 0; i < height;i++)
    {
        for(j =0; j < width;j++)
        {
            n = amplify3(&p[i*width + j]);
            if(n)
            {
                p[i*width + j] = 128;//太亮了就会出现黄白色
                if(( i%2==1)&&(j%2==1))
                {
                    long pix = (width >>1)*(i>>1)+(j>>1);
                    pcb[pix] = 200;
                    pcr[pix] = 200;
                    //pcb[pix] = 64;
                    //pcr[pix] = 64;
                    pcb[pix] = 200;
                    pcr[pix] = 64;

                }
            }
        }
    }

    p = buff;
    n = 0;
    int flen = framelen;
    while(flen)
    {
        n = fwrite(p, sizeof(char), flen, out);
        if(n > 0)
        {
            p += n;
            flen -= n;
        }
        else
            printf("fwrite err,%s\n",strerror(errno));
    }


}