使用进程我只将时间缩短了 15-20 秒，因为 ffmpeg 即使在单个进程中也几乎使用了全部 CPU 能力，而我的计算机没有能力更快地运行其他进程。
首先我减少了代码以使其更短。
try 和 except 中的代码具有相似的元素，所以我将它们移到了 try/except 之外。
接下来我用了
if end > video_duration:
end = video_duration
我根本不需要try/except。
使用os.makedirs(..., exist_ok=True)我不需要在try/except运行它
同时我用 20 秒缩短了时间
clip = VideoFileClip(filename).subclip(start, end)
而不是
temp_filename = f"{base_folder}/cut_{number}.mp4"
fmpeg_extract_subclip(filename, start, end, targetname=temp_filename)
clip = VideoFileClip(temp_filename)
这样我就不用在磁盘上写子剪辑，也不必从磁盘再次读取它。
from moviepy.video.io.ffmpeg_tools import ffmpeg_extract_subclip
from moviepy.editor import *
import time
def main():
text = input("Enter Your text please: ") [::-1]
#text = 'Hello World'
base_folder = time.strftime("result_%Y_%m_%d_%H_%M_%S")
os.makedirs(f"{base_folder}/result_edit", exist_ok=True)
filename = "video.mp4"
#filename = "BigBuckBunny.mp4"
video_duration = VideoFileClip(filename).duration
number = 0 # instead of `cut_name_num` and `txt_part` because both had the same value
time_start = time.time()
for start in range(0, int(video_duration), 60):
end = start + 60
if end > video_duration:
end = video_duration
number += 1
clip_duration = end - start
print(f'[DEBUG] number: {number:2} | start: {start:6.2f} | end: {end:6.2f} | duration: {clip_duration:.2f}')
final_text = f"{number} {text}"
temp_filename = f"{base_folder}/cut_{number}.mp4"
final_filename = f"{base_folder}/result_edit/cut_{number}.mp4"
#ffmpeg_extract_subclip(filename, start, end, targetname=temp_filename)
#clip = VideoFileClip(temp_filename)
clip = VideoFileClip(filename).subclip(start, end)
clip = clip.volumex(2)
txt_clip = TextClip(final_text, font="font/VarelaRound-Regular.ttf", fontsize=50, color='white')
txt_clip = txt_clip.set_pos(("center","top")).set_duration(60)
video = CompositeVideoClip([clip, txt_clip])
video.write_videofile(final_filename)
# - after loop -
# because I use `number += 1` before loop so now `number` has number of subclips
print('number of subclips:', number)
time_end = time.time()
diff = time_end - time_start
print(f'time: {diff:.2f}s ({diff//60:02.0f}:{diff%60:02.2f})')
if __name__ == "__main__":
main()
接下来我将代码移动到带有参数my_process(filename, text, start, end, number, base_folder)的函数
from moviepy.video.io.ffmpeg_tools import ffmpeg_extract_subclip
from moviepy.editor import *
import time
def my_process(filename, text, start, end, number, base_folder):
clip_duration = end - start
print(f'[DEBUG] number: {number:2} | start: {start:6.2f} | end: {end:6.2f} | duration: {clip_duration:.2f}')
final_text = f"{number} {text}"
temp_filename = f"{base_folder}/cut_{number}.mp4"
final_filename = f"{base_folder}/result_edit/cut_{number}.mp4"
#print('[DEBUG] ffmpeg_extract_subclip')
#ffmpeg_extract_subclip(filename, start, end, targetname=temp_filename)
#print('[DEBUG] VideoClip')
#clip = VideoFileClip(temp_filename)
clip = VideoFileClip(filename).subclip(start, end)
clip = clip.volumex(2)
#print('[DEBUG] TextClip')
txt_clip = TextClip(final_text, font="font/VarelaRound-Regular.ttf", fontsize=50, color='white')
txt_clip = txt_clip.set_pos(("center","top")).set_duration(60)
#print('[DEBUG] CompositeVideoClip')
video = CompositeVideoClip([clip, txt_clip])
#print('[DEBUG] CompositeVideoClip write')
video.write_videofile(final_filename)
#print('[DEBUG] CompositeVideoClip end')
def main():
text = input("Enter Your text please: ") [::-1]
#text = 'Hello World'
base_folder = time.strftime("result_%Y_%m_%d_%H_%M_%S")
os.makedirs(f"{base_folder}/result_edit", exist_ok=True)
filename = "video.mp4"
#filename = "BigBuckBunny.mp4"
video_duration = VideoFileClip(filename).duration
number = 0 # instead of `cut_name_num` and `txt_part` because both had the same value
time_start = time.time()
for start in range(0, int(video_duration), 60):
end = start + 60
if end > video_duration:
end = video_duration
number += 1
my_process(filename, text, start, end, number, base_folder)
# - after loop -
# because I use `number += 1` before loop so now `number` has number of subclips
print('number of subclips:', number)
time_end = time.time()
diff = time_end - time_start
print(f'time: {diff:.2f}s ({diff//60:02.0f}:{diff%60:02.2f})')
if __name__ == "__main__":
main()
现在我可以使用标准模块multiprocessing在分离的进程中运行函数
（或标准模块threading、concurrent.futures或外部模块Joblib、Ray等）。
它启动单个进程
# it has to use named arguments`target=`, `args=`
p = multiprocessing.Process(target=my_process, args=(filename, text, start, end, number, base_folder))
p.start() # start it
但如果我在循环中使用它，那么我将同时启动许多进程。
from moviepy.video.io.ffmpeg_tools import ffmpeg_extract_subclip
from moviepy.editor import *
import time
import multiprocessing
def my_process(filename, text, start, end, number, base_folder):
clip_duration = end - start
print(f'[DEBUG] number: {number:2} | start: {start:6.2f} | end: {end:6.2f} | duration: {clip_duration:.2f}')
final_text = f"{number} {text}"
temp_filename = f"{base_folder}/cut_{number}.mp4"
final_filename = f"{base_folder}/result_edit/cut_{number}.mp4"
#print('[DEBUG] ffmpeg_extract_subclip')
#ffmpeg_extract_subclip(filename, start, end, targetname=temp_filename)
#print('[DEBUG] VideoClip')
#clip = VideoFileClip(temp_filename)
clip = VideoFileClip(filename).subclip(start, end)
clip = clip.volumex(2)
#print('[DEBUG] TextClip')
txt_clip = TextClip(final_text, font="font/VarelaRound-Regular.ttf", fontsize=50, color='white')
txt_clip = txt_clip.set_pos(("center","top")).set_duration(60)
#print('[DEBUG] CompositeVideoClip')
video = CompositeVideoClip([clip, txt_clip])
#print('[DEBUG] CompositeVideoClip write')
video.write_videofile(final_filename)
#print('[DEBUG] CompositeVideoClip end')
def main():
text = input("Enter Your text please: ") [::-1]
#text = 'Hello World'
base_folder = time.strftime("result_%Y_%m_%d_%H_%M_%S")
os.makedirs(f"{base_folder}/result_edit", exist_ok=True)
filename = "video.mp4"
#filename = "BigBuckBunny.mp4"
video_duration = VideoFileClip(filename).duration
number = 0 # instead of `cut_name_num` and `txt_part` because both had the same value
time_start = time.time()
all_processes = []
for start in range(0, int(video_duration), 60):
end = start + 60
if end > video_duration:
end = video_duration
number += 1
print("add process:", number)
p = multiprocessing.Process(target=my_process, args=(filename, text, start, end, number, base_folder)) # it has to use `target=`, `args=`
p.start() # start it
all_processes.append(p) # keep it to use `join()`
# - after loop -
for p in all_processes:
p.join() # wait for the end of process
# because I use `number += 1` before loop so now `number` has number of subclips
print('number of subclips:', number)
time_end = time.time()
diff = time_end - time_start
print(f'time: {diff:.2f}s ({diff//60:02.0f}:{diff%60:02.2f})')
if __name__ == "__main__":
main()
11 个子剪辑的先前版本启动 11 个进程。使用Pool(4)，您可以将所有进程放入池中，它将同时运行 4 个进程。当一个进程完成任务时，它将使用新参数启动下一个进程。
这次我使用循环为所有进程创建带有参数的列表
args_for_all_processes = []
for start in range(0, int(video_duration), 60):
end = start + 60
if end > video_duration:
end = video_duration
number += 1
print("add process:", number)
args_for_all_processes.append( (filename, text, start, end, number, base_folder) )
我将这个列表与Pool 一起使用，剩下的事情就交给它了。
# I have 4 CPU so I use Pool(4) - but without value it should automatically use `os.cpu_count()`
with multiprocessing.Pool(4) as pool:
results = pool.starmap(my_process, args_for_all_processes)
#print(results)
Pool 可能会以不同的顺序启动进程，但如果他们使用return 发送一些结果，那么Pool 会以正确的顺序给出结果。
from moviepy.video.io.ffmpeg_tools import ffmpeg_extract_subclip
from moviepy.editor import *
import time
import multiprocessing
def my_process(filename, text, start, end, number, base_folder):
clip_duration = end - start
print(f'[DEBUG] number: {number:2} | start: {start:6.2f} | end: {end:6.2f} | duration: {clip_duration:.2f}')
final_text = f"{number} {text}"
temp_filename = f"{base_folder}/cut_{number}.mp4"
final_filename = f"{base_folder}/result_edit/cut_{number}.mp4"
#print('[DEBUG] ffmpeg_extract_subclip')
#ffmpeg_extract_subclip(filename, start, end, targetname=temp_filename)
#print('[DEBUG] VideoClip')
#clip = VideoFileClip(temp_filename)
clip = VideoFileClip(filename).subclip(start, end)
clip = clip.volumex(2)
#print('[DEBUG] TextClip')
txt_clip = TextClip(final_text, font="font/VarelaRound-Regular.ttf", fontsize=50, color='white')
txt_clip = txt_clip.set_pos(("center","top")).set_duration(60)
#print('[DEBUG] CompositeVideoClip')
video = CompositeVideoClip([clip, txt_clip])
#print('[DEBUG] CompositeVideoClip write')
video.write_videofile(final_filename)
#print('[DEBUG] CompositeVideoClip end')
# return "OK" # you can use `return` to send result/information to main process.
def main():
text = input("Enter Your text please: ") [::-1]
#text = 'Hello World'
base_folder = time.strftime("result_%Y_%m_%d_%H_%M_%S")
os.makedirs(f"{base_folder}/result_edit", exist_ok=True)
filename = "video.mp4"
#filename = "BigBuckBunny.mp4"
video_duration = VideoFileClip(filename).duration
number = 0 # instead of `cut_name_num` and `txt_part` because both had the same value
time_start = time.time()
# first create list with arguments for all processes
args_for_all_processes = []
for start in range(0, int(video_duration), 60):
end = start + 60
if end > video_duration:
end = video_duration
number += 1
print("add process:", number)
args_for_all_processes.append( (filename, text, start, end, number, base_folder) )
# - after loop -
# next put all processes to pool
with multiprocessing.Pool(4) as pool: # I have 4 CPU so I use Pool(4) - but it should use `os.cpu_count()` in `Pool()
results = pool.starmap(my_process, args_for_all_processes)
#print(results)
# - after loop -
# because I use `number += 1` before loop so now `number` has number of subclips
print('number of subclips:', number)
time_end = time.time()
diff = time_end - time_start
print(f'time: {diff:.2f}s ({diff//60:02.0f}:{diff%60:02.2f})')
if __name__ == "__main__":
main()