python - 为什么子进程ffmpeg损坏文件？

Question

我有以下代码，它读取视频并将其保存在另一个路径中，问题是保存文件时这是不可重现的吗？

import subprocess
import shlex
from io import BytesIO

file = open("a.mkv", "rb")

with open('a.mkv', 'rb') as fh:
    buf = BytesIO(fh.read())


args = shlex.split('ffmpeg -i pipe: -codec copy -f rawvideo pipe:')
proc = subprocess.Popen(args, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
out, err = proc.communicate(input=buf.getbuffer())
proc.wait()

f = open("a.mp4", "wb")
f.write(out)
f.close()

我需要保留缓冲区，视频大小正确，我该如何解决？

Answer 1

您可以使用 ffmpeg-python

pip install ffmpeg-python

接着:

import subprocess
import shlex
import ffmpeg
from io import BytesIO

file = open("a.mkv", "rb")

with open('a.mkv', 'rb') as fh:
    buf = BytesIO(fh.read())

process = (
    ffmpeg
    .input('pipe:') \
    .output('a.mp4') \
    .overwrite_output() \
    .run_async(pipe_stdin=True) \
)

process.communicate(input=buf.getbuffer())