【Codecs】yuvcut，实现yuv文件剪切功能

参考：https://stackoverflow.com/questions/17967278/extract-some-yuv-frames-from-large-yuv-file?rq=1

// include libraries
#include <fstream>
using namespace std;

#define P420 1.5

const int IMAGE_SIZE = 1920*1080;  // ful HD image size in pixels
const double IMAGE_CONVERTION = P420;
int n_frames = 300;  // set number of frames to copy
int skip_frames = 500;  // set number of frames to skip from the begining of the input file

char in_string[] = "F:\BigBucksBunny\yuv\BigBuckBunny_1920_1080_24fps.yuv";
char out_string[] = "out.yuv";


//////////////////////
//   main
//////////////////////
int main(int argc, char** argv)
{
    double image_size = IMAGE_SIZE * IMAGE_CONVERTION;
    long file_size = 0;

    // IO files
    ofstream out_file(out_string, ios::out | ios::binary);
    ifstream in_file(in_string, ios::in | ios::binary);

    // error cheking, like check n_frames+skip_frames overflow
    // 
    // TODO

    // image buffer
    char* image = new char[(int)image_size];

    // skip frames
    in_file.seekg(skip_frames*image_size);

    // read/write image buffer one by one
    for(int i = 0; i < n_frames; i++)
    {
        in_file.read(image, image_size);
        out_file.write(image, image_size);
    }

    // close the files
    out_file.close();
    in_file.close();

    printf("Copy finished ...");
    return 0;
}