Python实现视频分帧的方法分享

下载依赖

pip install opencv-python==4.0.0.21

实现

方法一

def video_to_frames(video_path, outPutDirName):
 """
 抽取视频帧存为图片
 :param video_path:
 :param outPutDirName:
 :return:
 """
 times = 0

 # 提取视频的频率，每1帧提取一个
 frame_frequency = 1

 # 如果文件目录不存在则创建目录
 if not os.path.exists(outPutDirName):
 os.makedirs(outPutDirName)

 # 读取视频帧
 camera = cv2.VideoCapture(video_path)

 while True:
 times = times + 1
 res, image = camera.read()
 if not res:
 print('not res , not image')
 break
 # 按照设置间隔存储视频帧
 if times % frame_frequency == 0:
 create_path = os.path.join(outPutDirName, f"{str(times)}.jpg")
 cv2.imwrite(create_path, image)

 logger.info('图片提取结束')
 # 释放摄像头设备
 camera.release()


def image_to_video(image_path, media_path, fps):
 '''
 图片合成视频函数
 :param image_path: 图片路径
 :param media_path: 合成视频保存路径
 :return:
 '''
 # 获取图片路径下面的所有图片名称
 image_names = os.listdir(image_path)
 # 对提取到的图片名称进行排序
 image_names.sort(key=lambda n: int(n[:-4]))
 # 设置写入格式
 fourcc = cv2.VideoWriter_fourcc('M', 'P', '4', 'V')
 # 设置每秒帧数
 fps = fps
 # 读取第一个图片获取大小尺寸，因为需要转换成视频的图片大小尺寸是一样的
 image = Image.open(os.path.join(image_path, image_names[0]))
 # 初始化媒体写入对象
 media_writer = cv2.VideoWriter(media_path, fourcc, fps, image.size)
 # 遍历图片，将每张图片加入视频当中
 for image_name in image_names:
 im = cv2.imread(os.path.join(image_path, image_name))
 media_writer.write(im)
 # 释放媒体写入对象
 media_writer.release()
 logger.info('无声视频写入完成！')

方法二

import numpy as np
import cv2
import os
import sys
def cut(video_file, target_dir):
 cap = cv2.VideoCapture(video_file) # 获取到一个视频
 isOpened = cap.isOpened # 判断是否打开
 # 为单张视频，以视频名称所谓文件名，创建文件夹
 temp = os.path.split(video_file)[-1]
 dir_name = temp.split('.')[0]

 single_pic_store_dir = os.path.join(target_dir, dir_name)
 if not os.path.exists(single_pic_store_dir):
 os.mkdir(single_pic_store_dir)


 i = 0
 while isOpened:

 i += 1

 (flag, frame) = cap.read() # 读取一张图像

 fileName = 'image' + str(i) + ".jpg"
 if (flag == True):
 # 以下三行 进行 旋转
 #frame = np.rot90(frame, -1)


 #print(fileName)
 # 设置保存路径
 save_path = os.path.join(single_pic_store_dir, fileName)
 #print(save_path)
 res = cv2.imwrite(save_path, frame, [cv2.IMWRITE_JPEG_QUALITY, 70])
 #print(res)
 else:
 break

 return single_pic_store_dir

if __name__ == '__main__':
 video_file = 'I:/crack.avi'
 cut(video_file, 'I:/data/')

方法三

#!/usr/bin/env python
import cv2
numer = 18
cap=cv2.VideoCapture("/home/linux/work/python/video/"+str(numer)+".mp4")

if cap.isOpened():
 ret,frame=cap.read()
else:
 ret = False

n=0
i=0
timeF = 40
path='/home/linux/work/python/video/'+str(numer)+'/{}'
while ret:
 n = n + 1
 ret,frame=cap.read()
 if (n%timeF == 0) :
 i = i+1
 print(i)
 filename=str(numer)+"_"+str(i)+".jpg"
 cv2.imwrite(path.format(filename),frame)
 cv2.waitKey(1)

cap.release()

补充

除了视频分帧，Python还可以将帧合成视频流，下面是实现代码

#!/usr/bin/env python
import cv2

img = cv2.imread('/home/linux/work/python/img/1_475.jpg')
imginfo = img.shape
size = (imginfo[1],imginfo[0])
print(size)
fourcc = cv2.VideoWriter_fourcc(*"mp4v")
videoWrite = cv2.VideoWriter('/home/linux/work/python/2.mp4',fourcc,10,size) 

for i in range(475,2208):
 filename = '/home/linux/work/python/img/1_'+str(i)+'.jpg'
 img = cv2.imread(filename,1)
 videoWrite.write(img) 
 print(i)

videoWrite.release()
print('end')