Describe the bug

When running MarkItDown on a Linux system, a RuntimeWarning is triggered by the pydub dependency. The warning indicates that ffmpeg or avconv is missing from the system path, which may cause audio-to-markdown conversion features to fail.

To Reproduce

1. Install markitdown in a Python 3.12 virtual environment on a Linux distribution.
2. Run a conversion command or import the library in a script.
3. Observe the following warning in the console:

   /markitdown/.venv/lib/python3.12/site-packages/pydub/utils.py:170: RuntimeWarning: Couldn't find ffmpeg or avconv - defaulting to ffmpeg, but may not work
     warn("Couldn't find ffmpeg or avconv - defaulting to ffmpeg, but may not work", RuntimeWarning)
   
   

Expected behavior

The library should either:

• Document ffmpeg as a required system-level dependency for Linux users.
• Handle the missing dependency gracefully if audio processing is not being actively used in the current task.

System Configuration

• OS: Linux
• Python Version: 3.12
• Environment: Virtual environment (.venv)