C语言对图片进行base64编码

  本人最近在做基于arm平台上的Linux系统的人脸识别模块，其中要用到的一小部分就是图片的base64编码的实现，自己琢磨了一下写了一个程序，还挺好用的，可以参考一下。

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>


const char * base64char = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

char * base64_encode( const unsigned char * bindata, char * base64, int binlength )
{
    int i, j;
    unsigned char current;

    for ( i = 0, j = 0 ; i < binlength ; i += 3 )
    {
        current = (bindata[i] >> 2) ;
        current &= (unsigned char)0x3F;
        base64[j++] = base64char[(int)current];

        current = ( (unsigned char)(bindata[i] << 4 ) ) & ( (unsigned char)0x30 ) ;
        if ( i + 1 >= binlength )
        {
            base64[j++] = base64char[(int)current];
            base64[j++] = '=';
            base64[j++] = '=';
            break;
        }
        current |= ( (uns