Add platform support note and existing file handling documentation to README and skill docs, clarifying Windows 11-only testing, per-script ffmpeg/ffprobe requirements, and file replacement behavior with -y flag across Clone-Image.md, Clone-Video.md, Compare-Videos.md, Crop-Clips.md, Get-VideoAudio.md, SKILL.md and index.md

README.md

@@ -5,8 +5,9 @@ A collection of PowerShell scripts for video processing tasks using ffmpeg and f
 ## Prerequisites
 
 - **PowerShell 7+** (pwsh.exe)
-- **ffmpeg** - Must be in system PATH
-- **ffprobe** - Must be in system PATH
+- **Platform**: tested on Windows 11 only. Linux and WSL are not tested and not supported.
+- **ffmpeg** - Must be in system PATH. Not needed by Get-FramesCount.ps1, Get-VideoInfo.ps1 and Create-FullSubtitle.ps1.
+- **ffprobe** - Must be in system PATH. Not needed by Stitch-InBetween.ps1.
 - **rife-ncnn-vulkan** - Must be in system PATH and also defined the environment variable **RIFE_HOME** to the same directory
 - **upscayl-bin** - Must be in system PATH and also defined the environment variable **UPSCAYL_HOME** to the same directory
 

skill/Clone-Image.md

@@ -197,6 +197,13 @@ The output format is selected from the `-Target` file extension. Each format has
 - **JPEG output is always 4:2:0 chroma** (`yuvj420p`). If you need 4:4:4 JPEG or 16-bit output, edit the encoder args directly.
 - **TIFF and BMP** are stored uncompressed (TIFF can be configured for LZW/Deflate via additional ffmpeg options if needed).
 
+## Existing Files
+
+- An existing `-Target` image is **replaced** without a prompt. ffmpeg runs with `-y`, so the old file is lost. Use `-WhatIf` first, or write to a new name.
+- An existing file at `-Keep` is replaced in the same way.
+- The folders that contain `-Target` and `-Keep` must already exist. The script stops with an error instead of creating them.
+- The temporary upscaled PNG is deleted when the script finishes.
+
 ## Safe Execution
 
 This script supports `-WhatIf` and `-Confirm` for safe execution:

skill/Clone-Video.md

@@ -456,6 +456,13 @@ The output container is selected from the `-Target` file extension. Each contain
 - **WebM encoding is slow.** `libvpx-vp9` is much slower than `libx264`; the chosen `cpu-used 2 -row-mt 1` settings strike a reasonable balance, but expect significantly longer rendering times than MP4.
 - **MKV stream-copy is greedy.** Because MKV accepts almost any codec, MKV output usually involves no re-encoding at all and is the fastest target for re-containerising downloads.
 
+## Existing Files
+
+- An existing `-Target` video is **replaced** without a prompt. ffmpeg runs with `-y`, so the old file is lost. Use `-WhatIf` first, or write to a new name.
+- The same applies to the image-to-video and PNG-sequence modes, and to a PNG that `-Sequence` would overwrite.
+- The folder that contains `-Target` must already exist. The script stops with an error instead of creating it.
+- The temporary concat list used for PNG sequences is deleted after the run.
+
 ## Safe Execution
 
 This script supports `-WhatIf` and `-Confirm` for safe execution:

skill/Compare-Videos.md

@@ -429,6 +429,12 @@ For 3 and 4 videos, S2 (and S3/S4 as needed) are probed to verify all sources ar
 - **Pixel Format:** yuv420p
 - **Audio:** Copied from S1 (unless `-NoAudio` specified)
 
+## Existing Files
+
+- An existing `-Output` video is **replaced** without a prompt. ffmpeg runs with `-y`, so the old file is lost. Use `-WhatIf` first, or write to a new name.
+- The folder that contains `-Output` must already exist. The script stops with an error instead of creating it.
+- The source videos are only read and are never modified.
+
 ## Notes
 
 - Requires `ffmpeg` and `ffprobe` in system PATH

skill/Crop-Clips.md

@@ -115,6 +115,7 @@ An invalid `-Size` value fails immediately, before any file is processed.
 - Preserves original quality and audio
 - **In-place mode** (source and target are the same directory). This is the default when `-Source` and `-Target` are both omitted, because both default to the current directory:
     - Each original `video.mp4` is copied to `video.bak.mp4`. An existing `.bak.mp4` is replaced.
+    - Only files that are cropped are backed up. A file that is skipped, because it is already at the requested size or its resolution is not in the table, keeps its existing `.bak.mp4`. Re-running in place without `-Size` skips the files it already cropped, so the backup stays the original. A re-run with a different `-Size` crops them again, and replaces the backup with the first run's output. Keep your own copy of the originals before a re-run with a different `-Size`, or use a separate `-Target` folder.
     - The cropped result is written to `video.crop.mp4`. Only after that succeeds is the original `video.mp4` deleted and replaced by the cropped file. The `.bak.mp4` backup is kept.
     - Run with `-WhatIf` first, and do not run it on a folder you have not designated.
 - **Separate target folder**: the source files are not changed. A file with the same name already in the target folder is deleted and replaced.

skill/Get-VideoAudio.md

@@ -53,7 +53,12 @@ Extracts audio in either WAV or MP3 format from a video file.
 - If the video file has no audio stream, the script displays a message and exits without creating an output file
 - WAV format uses PCM 16-bit encoding (lossless)
 - MP3 format uses 320 kbps bitrate (highest quality)
-- If output file already exists, it will be overwritten
+
+## Existing Files
+
+- An existing output file, the default `<video>.wav` or `<video>.mp3`, or the `-Output` path, is **replaced** without a prompt. ffmpeg runs with `-y`, so the old file is lost. Use `-WhatIf` first, or write to a new name.
+- If the output folder does not exist, ffmpeg fails and the script stops with an error.
+- If the video has no audio stream, the script prints a message and exits successfully. It creates no file and leaves any existing output untouched.
 
 ## Safe Execution
 

skill/SKILL.md

@@ -9,8 +9,9 @@ A collection of PowerShell 7 scripts that wrap ffmpeg and ffprobe for video and
 
 ## Prerequisites
 
+- **Platform**: Windows 11 only. The scripts are tested on Windows 11 and nowhere else. Do not run them on Linux or WSL, because those platforms are not supported.
 - **PowerShell 7+** (`pwsh`). Required by every script.
-- **ffmpeg** and **ffprobe** on `PATH`. Required by every video script.
+- **ffmpeg** and **ffprobe** on `PATH`. Most scripts need both. [Stitch-InBetween.ps1](Stitch-InBetween.md) needs only ffmpeg. [Get-FramesCount.ps1](Get-FramesCount.md), [Get-VideoInfo.ps1](Get-VideoInfo.md) and [Create-FullSubtitle.ps1](Create-FullSubtitle.md) need only ffprobe.
 - **rife-ncnn-vulkan** on `PATH`, with `RIFE_HOME` set. Required by [Stitch-InBetween.ps1](Stitch-InBetween.md). See [RIFE installation guide](RIFE.md).
 - **upscayl-bin** on `PATH`, with `UPSCAYL_HOME` set. Required by [Clone-Image.ps1](Clone-Image.md) when `-Upscale` is used. See [Upscalers installation guide](Upscalers.md).
 

skill/index.md

@@ -5,8 +5,9 @@ A collection of PowerShell scripts for video processing tasks using ffmpeg and f
 ## Prerequisites
 
 - **PowerShell 7+** (pwsh.exe)
-- **ffmpeg** - Must be in system PATH
-- **ffprobe** - Must be in system PATH
+- **Platform**: tested on Windows 11 only. Linux and WSL are not tested and not supported.
+- **ffmpeg** - Must be in system PATH. Not needed by Get-FramesCount.ps1, Get-VideoInfo.ps1 and Create-FullSubtitle.ps1.
+- **ffprobe** - Must be in system PATH. Not needed by Stitch-InBetween.ps1.
 - **rife-ncnn-vulkan** - Must be in system PATH and also defined the environment variable **RIFE_HOME** to the same directory
 - **upscayl-bin** - Must be in system PATH and also defined the environment variable **UPSCAYL_HOME** to the same directory