import os
import cv2 as cv
import numpy as np


# 讀取yuv420p的一幀文件，并轉化為png圖片
if __name__ == '__main__':
  filepath = 'one_frame_of_highway.yuv'
  binfile = open(filepath, 'rb')
  size = os.path.getsize(filepath)
  image_width = 352
  image_hight = 288
  image_y = [[0] * image_width for i in range(image_hight)]
  image_u = [[0] * image_width for i in range(image_hight)]
  image_v = [[0] * image_width for i in range(image_hight)]
  for r in range(image_hight):
    for c in range(image_width):
      image_y[r][c] = binfile.read(1)[0]
  Image_Y = np.array(image_y)

  for r in range(int(image_hight / 2)):
    for c in range(int(image_width / 2)):
      pixel = binfile.read(1)[0]
      image_u[2 * r + 0][2 * c + 0] = pixel
      image_u[2 * r + 1][2 * c + 0] = pixel
      image_u[2 * r + 0][2 * c + 1] = pixel
      image_u[2 * r + 1][2 * c + 1] = pixel
  Image_U = np.array(image_u)

  for r in range(int(image_hight / 2)):
    for c in range(int(image_width / 2)):
      pixel = binfile.read(1)[0]
      image_v[2 * r + 0][2 * c + 0] = pixel
      image_v[2 * r + 0][2 * c + 1] = pixel
      image_v[2 * r + 1][2 * c + 0] = pixel
      image_v[2 * r + 1][2 * c + 1] = pixel
  Image_V = np.array(image_v)
  binfile.close()
  compose = np.array([Image_Y, Image_V, Image_U]).transpose([1, 2, 0]).astype(np.uint8)
  Image = cv.cvtColor(compose, cv.COLOR_YUV2RGB)
  cv.imwrite("one_frame_of_highway.yuv.png", Image)

 ffmpeg -s 352x288 -i one_frame_of_highway.yuv one_frame_of_highway.png

#include stdio.h>
#include fcntl.h>
#include zconf.h>
#include stdint.h>
#include strings.h>
#include stdlib.h>
#include string.h>
#include unistd.h>
#include errno.h>
#include sys/types.h>
#include sys/stat.h>
int File_Size(int fd) {
  struct stat st;
  fstat(fd, st);
  return st.st_size;
}

int Frame_Size_Of_Cif() {
  int width = 352;
  int heigh = 288;
  int Y_SIZE = width * heigh;
  int U_SIZE = Y_SIZE / 4;
  int V_SIZE = Y_SIZE / 4;
  int Frame_SIZE = Y_SIZE + U_SIZE + V_SIZE;
  return Frame_SIZE;
}

int Frames_Of_Cif_File(int fd) {
  if (fd  0) {
    printf("Invalid FD!");
    return -1;
  }
  int Frame_SIZE = Frame_Size_Of_Cif();
  int fd_size = File_Size(fd);
  return fd_size / Frame_SIZE;
}

void Abstract_Frame_From_CIF_File(int fd,char *Path_And_Prefix_Img,int Len) {
  int Frame_SIZE = Frame_Size_Of_Cif();
  char file[128];
  memset(file,0,128);
  memcpy(file,Path_And_Prefix_Img,Len);
  uint8_t buf[Frame_SIZE];
  int ret = -1;
  int frames = 0;
  while ((ret = read(fd, buf, Frame_SIZE))) {
    frames += 1;
    uint64_t len = strlen(file);
    sprintf(file + len, "%d", frames);
    len = strlen(file);
    sprintf(file + len, "%s", ".yuv");
    int fdw = open(file, O_RDWR | O_CREAT, 0777);
    write(fdw, buf, ret);
    memset(file,0,128);
    memcpy(file,Path_And_Prefix_Img,Len);
    close(fdw);
  }
  printf("Abstract %d frames!\n", frames);
}


int main() {

  int fd = open("./yuv420p_352x288.yuv", O_RDONLY);
  Abstract_Frame_From_CIF_File(fd,"/home/liu/Frames/Frames_",strlen("/home/liu/Frames/Frames_"));
  close(fd);
  return 0;
}