❓ Frequently Asked Questions

❔ The program freezes during scanning, what should I do?

Answer: Most likely, you are using the CNN+Faiss algorithm with a large number of frames (more than 200).

Solution:

1. Press the "Stop" button – the program will terminate the current operation.
2. Reduce the number of frames to 100 or less.
3. Switch to the pHash algorithm.
4. Scan smaller folders or turn on pre‑filtering.

❔ The program does not find similar videos even though I know they exist

Answer: The similarity threshold may be too high, or the videos differ significantly (different resolution, cropping).

Solution:

1. Lower the similarity threshold to 0.6.
2. Use the CNN+Faiss algorithm (more robust to changes).
3. Increase the number of frames (to 100‑200).
4. Turn on "Crop black borders" if the videos contain letterbox.
5. Check whether the folders have been added to the ignore list.

❔ Can deleted files be recovered?

Answer: This depends on the action you chose:

• Move to Trash – yes, files can be restored from the Windows Recycle Bin.
• Delete permanently – no, specialised data recovery software would be required.
• Move to folder – files are not deleted; you can find them in the chosen folder.

❔ Are other video formats supported?

Answer: Currently supported formats are: MP4, AVI, MOV, MKV, WMV, FLV, WEBM, M4V, MPG, MPEG, 3GP, OGV, TS, M2TS, VOB, DIVX, XVID, F4V, MTS. If your format is not supported, you can convert it to one of the supported formats.

❔ Can I compare videos of different quality and resolution?

Answer: Yes, the algorithms handle this well:

• pHash – robust to changes in size, brightness, and compression.
• CNN+Faiss – recognises videos even with significant changes in resolution and bitrate.

❔ What should I do if the program gives an error when opening a video?

Answer: Check the following:

1. The file is not corrupted and opens in a video player (e.g., VLC).
2. The program has read permissions for the file (try running as administrator).
3. The format is supported (MP4, AVI, MOV, MKV, WMV, FLV, WEBM, M4V, MPG, MPEG, 3GP, OGV, TS, M2TS, VOB, DIVX, XVID, F4V, MTS).
4. The file path does not contain special characters (e.g., emojis).
5. Try converting the file to MP4 using ffmpeg or another converter.

❔ How to choose what to delete when similarity is 50‑70%?

Answer: In this range, videos may be partially similar (common scenes, edits). Recommendations:

1. Use the synchronous view (the "🎬 Synchronous View" button) for visual comparison.
2. Compare size and resolution – keep the file with better parameters.
3. Check the duration – one version may be more complete.
4. If in doubt, do not delete – it is better to keep both.

❔ The program works slowly, how can I speed it up?

Answer: There are several ways:

• Use the pHash algorithm (it is faster than CNN+Faiss).
• Reduce the number of frames (to 30 for pHash, to 50 for CNN).
• Enable pair pre‑filtering – this immediately discards obviously unsuitable pairs.
• Add large folders to the ignore list.
• Close other heavy programs (browser, video editors).
• Scan folders one by one instead of all at once.

❔ How to use search in the results?

Answer: There is an input field in the lower results panel. Start typing a file name (or part of a path) – the list of pairs will be filtered, showing only those where at least one file contains the entered text (case‑insensitive). The cross button clears the search.

❔ Can I add my own folders to the exceptions?

Answer: Yes, using the "🚫 Add folder to ignore list" button. You can manage the list via "📋 Manage ignore list".

❔ What do the colours in the file information mean?

Answer: When comparing two files in a pair, the characteristics (size, duration, resolution, FPS, number of frames) are coloured:

• Green – this file has a better value (smaller size, higher resolution, higher FPS, longer duration).
• Red – the value is worse.
• Black – the values are equal (or close).

This helps you quickly decide which file to keep when deleting.

❔ Where are the settings stored?

Answer: All settings are saved in the user_settings.json file in %APPDATA%\VideoDuplicateCleaner. You can copy them to another computer to transfer settings.

❔ How to pause or stop scanning?

Answer: During scanning, the buttons «⏸️ Pause», «▶️ Resume» and «⏹️ Stop» appear. Pause temporarily halts processing, stop completely cancels scanning (results obtained before stopping remain). More details in the "Scan Control" section.

❔ Why does the program not see videos in a folder?

Answer: Check the following:

1. The video format must be among the supported ones: MP4, AVI, MOV, MKV, WMV, FLV, WEBM, M4V, MPG, MPEG, 3GP, OGV, TS, M2TS, VOB, DIVX, XVID, F4V, MTS.
2. The folder has not been added to the ignore list (menu «Tools» → «Manage ignore list»).
3. In the pre‑filtering settings, filters that exclude files by size/duration/name are not enabled.
4. The file is not corrupted and is readable (try opening it with a video player).

❔ How to use regular expressions in pre‑filtering?

Answer: In the pre‑filtering dialog there is a "Filename" field and a "Use regular expression" checkbox. Examples:

• ^part\d+ – names starting with "part" followed by digits.
• \.(mp4|avi)$ – files ending with .mp4 or .avi.
• In the "Exclude" field – temp|backup – exclude files containing "temp" or "backup".

Regular expressions support Python re syntax.

❔ Can cache clearing be undone?

Answer: No, the cache is deleted permanently. But this is safe – the next time you scan, previews will be recreated, and the video files themselves are not affected.

❔ What to do if the program freezes when scanning with CNN+Faiss?

Answer: Most likely, you have chosen too many frames (e.g., >500). Use the recommended values (up to 100 frames). You can also disable pair pre‑filtering or temporarily switch to pHash. If the problem persists, report the error to support.