录像带在早期被采集成一个AVI文件和一个临时文件，怎样编辑合成一个如何将视频改成mp4格式文件？

来源：蜘蛛抓取(WebSpider) 时间：2023-09-28 06:00 标签： 如何将视频改成mp4格式
前几天故宫博物院的单霁翔老师来天津做讲座，但是很遗憾讲座名额有限，没有机会亲临现场聆听老先生的讲演。但是好在同事对现场录音和拍照，看了一下录音和照片的时间戳，大致可以合的上，因此萌生出把照片和录音合并在一起的想法。不说废话，码上开干。起初的思路是用ffmpeg库把照片按照关键帧的顺序插进音频中，合成完整的视频。但是玩过视频的人都知道，这么做是不可能成立的。于是调整思路，先把照片时间戳找出来，构建字典，key是时间戳，value是照片名称。然后就用到了传说的opencv，按照音频/照片序列时长，生成avi文件。当然，这时的avi文件很大，有一个多G，没关系，后面用ffmpeg压缩一下转成了49m的mp4文件。现在有了视频文件，然后在ffmpeg中把录音和这个合成的视频文件合并一下就可以了。代码如下：# -*- coding: utf-8 -*-
import exifread
import os
import json
import time
import subprocess
import cv2
from cv2 import VideoWriter, VideoWriter_fourcc, imread, resize
def getexiftime(imgname):
'''get the exif info of image
'''
with open(imgname, 'rb') as f:
tags = exifread.process_file(f, stop_tag='Image DateTime')
# tags['Image DateTime'].values = "2019:12:19 14:26:00"
imgtimestamp = time.strptime(
tags['Image DateTime'].values, '%Y:%m:%d %H:%M:%S')
imgtimestamp = time.mktime(imgtimestamp)
return imgtimestamp
# like 1576736760
def maketimedict(path):
'''make a dict ,key is the imgtimestamp, value is the name of image
path: dir of images, string
'''
res = dict()
for item in os.listdir(path):
imgpath = f'{path}/{item}'
if os.path.isfile(imgpath):
try:
imgtimestamp = getexiftime(imgpath)
key = int(float(imgtimestamp))
res.setdefault(key, item)
except Exception:
continue
return res
def savejson(imgdict, outfile):
'''save the imgdict as a json file
'''
with open(outfile, 'w') as fp:
json.dump(imgdict, fp)
return outfile
def loadjson(infile):
'''load the json file as dict
but the key will turn to string
'''
with open(infile, 'r') as fp:
res = json.load(fp)
return res
def combinevideo(invideodir, inaudiodir):
outputfile = "output.mp4"
command1 = f"ffmpeg -i {invideodir} test.mp4"
# 压缩视频文件
subprocess.call(command1)
command2 = f"ffmpeg -i test.mp4 -i {inaudiodir} -c:v copy -c:a aac -strict experimental {outputfile}"
# 合并视频音频
subprocess.call(command2)
return outputfile
def makevideo(imgdict, imgdir):
'''combine the images to video, no audio
imgdict: keys:time, values:img name
imgdir: dir of images'''
audiostart = 1576736760
audioend = 1576745959
imgstart = min(imgdict.keys())
# 1576737005
imgend = max(imgdict.keys())
# 1576746028
imgdir = "../images/"
outdir = "./test.avi"
count_frames = max([imgend, audioend]) - min([imgstart, audiostart]) + 1
fps = 1
size = (640, 480)
fourcc = VideoWriter_fourcc(*"MJPG")
videowriter = cv2.VideoWriter(outdir, fourcc, fps, size)
inputstr = imgdir + imgdict[imgstart]
for i in range(count_frames):
im_key = min([imgstart, audiostart]) + i
im_name = imgdict.get(im_key)
if im_name:
inputstr = imgdir + im_name
print(inputstr, 'time is ', im_key, i/count_frames*100, '%')
frame = imread(inputstr)
frame = resize(frame, size)
videowriter.write(frame)
videowriter.release()
return outdir
def main():
imgdir = "../images"
imgdict = maketimedict(imgdir)
savejson(imgdict, 'imgtime.json')
# 存一下，以防万一
makevideo(imgdict, imgdir)
# 生成中间文件，test.avi
invideodir = "test.avi"
inaudiodir = "../audio/191219_001.mp3"
combinevideo(invideodir, inaudiodir)
# 生成最终合成文件， output.mp4
if __name__ == "__main__":
main()

我要回帖

更多关于 如何将视频改成mp4格式 的文章

 

随机推荐