Refactor FFmpeg documentation to improve clarity by removing redundant headings and enhancing the organization of examples.

Author: 0xfab1

docs/tech/tools/cli/ffmpeg.md

@@ -22,16 +22,12 @@ Links:
 
 ## File Information
 
-**Get codec details**
-
 Get codec details of a given video file e.g. "video.mp4":
 
 ``` sh
 ffprobe -v error -select_streams v:0 -show_entries stream=codec_name -of default=noprint_wrappers=1:nokey=1 video.mp4
 ```
 
-**Overwrite the video title**
-
 Change the title of input.mp4 to "My Title"
 
 ``` sh
@@ -62,6 +58,12 @@ Analyze video frames, timecode and metadata
 ffmpeg -i input.mp4 -vf showinfo -f null -
 ```
 
+Check if all mp4s in a folder are fine
+
+``` ps1
+Get-ChildItem -Filter "*.mp4" | ForEach-Object { Write-Host "Checking: $($_.Name)"; ffmpeg -v error -i $_.FullName -f null - 2>&1 | Where-Object { $_ -ne '' } | ForEach-Object { Write-Host $_ } }
+```
+
 ## Download video streams
 
 Locate the playlist file, e.g. using Chrome > F12 > Network > Filter: m3u8