Python3调用FFmpeg实现RTSP转RTMP时遇语法错误求助

Hey Chris, let's work through this syntax error issue step by step—this is a common pitfall when mixing shell commands with Python string handling!

The Core Issues #

Your error is likely coming from two key problems in how you're defining the FFmpeg command in Python:

1. Quotation mark conflicts between your Python string and the RTSP URL's wrapping quotes
2. Incorrect URL escaping: You're using HTML-style & instead of raw & in the RTSP link, which FFmpeg won't recognize as valid URL syntax

Fix 1: Resolve String Quotation Conflicts #

When writing shell commands in Python, using triple quotes (either ''' or """) eliminates conflicts between inner and outer quotation marks. Here's a quick fix:

import subprocess

# Use triple single quotes to avoid quote clashes
ffmpeg_cmd = '''ffmpeg -i "rtsp://xx.xxx.xx.x:554/user=admin&password=123@&channel=1&stream=0.sdp" -f flv -r 25 -s 640x480 -an "rtmp://localhost:1935/uid/1/camera1"'''
subprocess.run(ffmpeg_cmd, shell=True)

Fix 2: Use a Safer Command Structure (Avoid shell=True) #

A better practice is to split your command into a list of arguments. This avoids shell escaping entirely and reduces security risks:

import subprocess

# Split each command/parameter into a separate list element
ffmpeg_cmd = [
    'ffmpeg',
    '-i',
    'rtsp://xx.xxx.xx.x:554/user=admin&password=123@&channel=1&stream=0.sdp',
    '-f', 'flv',
    '-r', '25',
    '-s', '640x480',
    '-an',
    'rtmp://localhost:1935/uid/1/camera1'
]
# Add check=True to catch FFmpeg runtime errors early
subprocess.run(ffmpeg_cmd, check=True)

Critical Note: Fix the RTSP URL #

You had & in your original RTSP link—this is an HTML escape sequence, not valid for a raw RTSP URL. Replace all instances of & with plain & so FFmpeg can correctly parse the stream parameters.

Quick Troubleshooting Tip #

If you still run into issues, test the FFmpeg command directly in your Ubuntu terminal first. If it works there, the problem is definitely with how Python is handling the string/arguments. If it fails in the terminal, you'll need to debug the RTSP URL itself (check credentials, stream path, or camera accessibility).

内容的提问来源于stack exchange，提问作者Walshie1987