How to merge two video parts and get a playable video file using Python? - subprocess

Question

Here, I actually wants to merge two strings out1 & out2 (which contains the first and second 30sec long video data) and write that to a file. So that I will get a 1min long playable video file. But what I am getting is the first 30sec video only. How should I edit this code to achieve that ? Please help me. Thanks a lot in advance.
import subprocess,os
ffmpeg_command1 = ["ffmpeg", "-i", "PATH/connect.webm", "-vcodec", "copy", "-ss", "00:00:00", "-t", "00:00:30","-f", "webm", "pipe:1"]
p1 = subprocess.Popen(ffmpeg_command1,stdout=subprocess.PIPE)
out1, err = p1.communicate()
ffmpeg_command2 = ["ffmpeg", "-i", "PATH/connect.webm","-vcodec", "copy", "-ss", "00:00:31", "-t", "00:00:30","-f", "webm", "pipe:1"]
p2 = subprocess.Popen(ffmpeg_command2,stdout=subprocess.PIPE)
out2, err1 = p2.communicate()
string = out1 + out2
fname = "PATH/final.webm"
fp = open(fname,'wb')
fp.write(string)
fp.close()
Please help me. I struck.

Answer 1

If you want to concat two videos with ffmpeg, it works like that:
ffmpeg -vcodec copy -isync -i \
"concat:file1.mp4|file2.mp4|...|fileN.mp4" \
outputfile.mp4

Answer 2

#coding=utf-8
import os
#Function to create a file list in the folder
import os
s = os.sep
path = r"F:\folder_mp4_files\temp"
def create_file_list(path):
return_list = []
for filenames in os.walk(path):
for file_list in filenames:
for file_name in file_list:
if file_name.endswith((".mp4")):
return_list.append(path+s+file_name)
return return_list
alist = create_file_list(path)
tsString = '|'.join([i.replace('.mp4','.ts') for i in alist])
print(tsString)
# mp4 converts to ts
for i in alist:
noExtension = i.replace('.mp4','')
# batch processing
os.system("ffmpeg -i %s -vcodec copy -acodec copy -vbsf h264_mp4toannexb %s.ts" % (i,noExtension))
# Remove used mp4 files
for i in alist:
os.remove(i)
os.system("""ffmpeg -i concat:"{0}" -acodec copy -vcodec copy -absf aac_adtstoasc {1}""".format(tsString, alist[0]))
# Remove used ts files
for i in alist:
os.remove(i.replace('.mp4','.ts'))