如何在docker容器中设置ffmpeg

Question

我想在python中使用ffmpeg压缩项目目录中的视频

视频保存自cv2.VideoCapture(rtsp_url)

通常它在我的本地机器上运行没有问题，但是当我dockerize我的应用程序时，似乎docker容器不能识别ffmpeg或我错过了一些东西。

def compress(name):
with open(name) as f:
output = name[0:-4] + "-f"+ ".mp4"
input = name
subprocess.run('ffmpeg -i ' + input + ' -vcodec libx264 ' + output)
video = cv2.VideoCapture(rtsp_url) # This is where the video comming from
fileName = saveToProjDir(video) # Save the video to project directory and return the name
compress(fileName) # Compress the video

抛出异常

Exception in thread Thread-8 (compress):
Traceback (most recent call last):
File "/usr/local/lib/python3.11/threading.py", line 1038, in _bootstrap_inner
self.run()
File "/usr/local/lib/python3.11/threading.py", line 975, in run
self._target(*self._args, **self._kwargs)
File "/app/main.py", line 59, in compress
subprocess.run('ffmpeg -i ' + input + ' -vcodec libx264 ' + output)
File "/usr/local/lib/python3.11/subprocess.py", line 546, in run
with Popen(*popenargs, **kwargs) as process:
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/subprocess.py", line 1022, in __init__
self._execute_child(args, executable, preexec_fn, close_fds,
File "/usr/local/lib/python3.11/subprocess.py", line 1899, in _execute_child
raise child_exception_type(errno_num, err_msg, err_filename)
FileNotFoundError: [Errno 2] No such file or directory: 'ffmpeg -i cam1_2022-11-15125845.avi -vcodec libx264 cam1_2022-11-15125845-f.mp4'

这是我如何docker我的python应用。

FROM python:3.11.0
WORKDIR /app/
ENV VIRTUAL_ENV = /env
RUN python3 -m venv $VIRTUAL_ENV
ENV PATH="$VIRTUAL_ENV/bin:$PATH"
COPY requirements.txt .
RUN pip install -r requirements.txt
RUN apt-get -y update
RUN apt-get install ffmpeg libsm6 libxext6  -y
ADD main.py .
CMD ["python","/app/main.py"]

Answer 1

要调试您的问题，我的建议是交互式地使用您的容器。

试着运行一个新的容器:

docker run -t -i <image-name-or-container-id> /bin/bash

或连接到正在运行的容器:

docker exec -i -t <container-id> /bin/bash

通过这种方式，您可以尝试从不同的路径启动ffmpeg，安装其他依赖项，最后看看您缺少什么。

Answer 2

如果问题开头提到的python脚本是main.py的内容，那么实现就没有什么问题了:

• 不能以python:3.11.0作为基本镜像运行docker
• 您需要挂载带有视频的卷并在容器中处理它们。