Editing Troubleshooting of FFmpeg (section)

== File Overwrite Issue When Integrating FFmpeg with PHP ===

'''Error condition''':
When integrating FFmpeg commands with PHP scripts, if the output file already exists, FFmpeg displays an overwrite confirmation prompt. However, this prompt is not visible in the PHP execution environment. This causes the PHP script to pause, waiting for user input, without any visible prompt.

Original command:
<pre>
ffmpeg -i input.mp4 -vf scale=720:404 -c:v libx264 -crf 23 -preset fast -c:a aac -b:a 128k output.mp4
</pre>

Prompt in terminal environment:
<pre>
File 'output.mp4' already exists. Overwrite? [y/N]
</pre>

'''Solution''':
Add parameters to the FFmpeg command to control file overwrite behavior:
  
First option: '''Auto-overwrite option''':
<pre>
ffmpeg -y -i input.mp4 -vf scale=720:404 -c:v libx264 -crf 23 -preset fast -c:a aac -b:a 128k output.mp4
</pre>
  
Second option: '''Skip if file exists option''':
<pre>
ffmpeg -n -i input.mp4 -vf scale=720:404 -c:v libx264 -crf 23 -preset fast -c:a aac -b:a 128k output.mp4
</pre>

Or implement the file overwrite control directly in your PHP script logic.