#-*- coding: utf-8 -*-
#使用本程序的方法：
#1. 安装python3
#2. 安装numpy， 命令 pip3 install numpy
#3. 安装opencv-python， 命令：pip3 install opencv-python
#4. 将该脚本放置在存储视频的文件夹中，利用python执行此脚本。

import os
import sys
filedir = os.path.dirname(sys.argv[0])      #获取脚本所在目录
os.chdir(filedir)       #将脚本所在的目录设置为工作目录
wdir = os.getcwd()
print('当前工作目录：{}\n'.format(wdir))      #打印当前工作目录

import numpy as np
import cv2 as cv;
import re
from math import ceil

def video_to_image(video_path):
    print('\n-----------------------------------------------------------------------------')
    print('正在处理视频：{}\n'.format(video_path))
    
    video_dir = os.path.dirname(video_path)
    video_name = os.path.basename(video_path)
    
    image_dir = re.sub('\.','_',video_name)
    image_dir = os.path.join(video_dir, image_dir)
    if not os.path.exists(image_dir):
        os.mkdir(image_dir)

    cap = cv.VideoCapture(video_path)
    # Define the codec and create VideoWriter object
    fps = cap.get(5)   #视频帧率
    width = cap.get(3)
    height = cap.get(4)
    sample_rate = round(fps)   #采样率，目前设置为每秒取1帧。
    
    #print("视频  {}  的帧率为:{:.2f}  分辨率为:{} ✖ {}".format(video_path, fps, width, height))
    print("视频  {} 的帧率为：{}  分辨率为：{} * {}".format(video_path, fps, width, height))
	
    n=0
    new_img_num = 0
    old_img_num = 0
    while(cap.isOpened()):
        ret, frame = cap.read()
        if ret==True:
            #cv.imshow('frame1', frame)
            n=n+1
            
            if n%sample_rate == 1:
                
                image_name = video_name+'_'+str(n)+'.jpg'
                image_path = os.path.join(image_dir, image_name)
                if os.path.exists(image_path):
                    print('{}  已经存在。'.format(image_path))
                    old_img_num += 1
                else :
                    print(image_path)
                    cv.imwrite(image_path,frame)
                    new_img_num += 1
            
            if cv.waitKey(1) & 0xFF == ord('q'):
                break
        else:
            break
        
    # Release everything if job is finished

    cap.release()
    print('视频处理完毕，共{}帧。每{}帧采1张，可生成{}张图片。\n'.format(n, sample_rate, ceil(n/sample_rate)))
    print('此前已有图片{}张，本次生成{}张。\n'.format(old_img_num, new_img_num))

ext = ('.h264', '.MOV')
#遍历工作目录，并对其中指定格式的视频文件进行处理。    
# def search(path):
    # for p in os.listdir(path):
        # p = os.path.join(path, p)
        # if os.path.isdir(p):
            # search(p)
        # elif p.endswith(ext):
            # video_to_image(p)

# search(wdir) 

for dirpath, dirname, filename in os.walk(wdir):
    for f in filename:
        if f.endswith(ext):
            video_path = os.path.join(dirpath, f)
            video_to_image(video_path)