YouTube Reverse Player

"Did you ever watch teardown or how-to-disassemble tutorial videos,
but then had trouble putting it all back together?
Here's your solution: easily reverse any YouTube video so you can watch it in reverse.
Learn exactly how to reassemble that gadget you just tore apart!"

This script downloads a YouTube video, reverses it (in a two-step process), and then plays it back in a simple GUI.
You can quickly scrub through frames, play/pause, adjust playback speed, and jump frame-by-frame. The encoding process is optimized for speed rather than output video quality to provide quick results.

Features

• Download any YouTube video (up to 1024p, by default)
• Two-step Reversal using FFmpeg:
  1. Reverse + reset timestamps
  2. Re-encode at your chosen FPS
• GUI Controls for playback:
  • Play / Pause / Stop
  • Scrub timeline
  • Frame-by-frame navigation
  • Playback speed slider
• Optional: Choose a custom temporary folder to store intermediate files
• Minimal dependencies: Python, yt-dlp, ffmpeg, and VLC (for libvlc)

Requirements

1. Python 3.9+
   • Download from python.org if needed
   • Make sure to check "Add Python to PATH" when installing
2. FFmpeg (must be available as ffmpeg in your PATH, or place ffmpeg.exe in the same folder)
   • You can download from ffmpeg.org
3. VLC (installed normally, or manually provide libvlc.dll and plugins)
   • Download from videolan.org/vlc
   • Typically installing with default options ensures python-vlc can find libvlc.dll
4. Tested primarily on Windows, but should work on macOS or Linux if the above requirements are met

Installation / Getting Started

1. Clone this repository:

   https://github.com/roundyyy/YouTube-Reverse-Player.git

   Or download the ZIP and extract it.

2. (Optional) If you haven't already:

   • Install Python 3.9+
   • Install VLC
   • Install FFmpeg

3. Double-click start.bat on Windows:

   • This will:
     • Check if Python is installed
     • Install the Python dependencies (yt-dlp, python-vlc) via requirements.txt
     • Launch the GUI tool

That's it! If everything is installed, you should see the tool's GUI window.

Usage

1. YouTube URL: Paste the link of the video you want to reverse (up to 1024p)
2. Refresh Info: Click Refresh Info to see the available resolutions
3. Choose Resolution: Select the resolution you want to download
4. Output FPS: Use the slider to choose the FPS for the reversed video
5. Generate: Click Generate Reversed Video
   • The tool will:
     • Download the chosen format of the video via yt-dlp
     • Reverse it in two steps using FFmpeg
     • Load it into the built-in VLC player
6. Controls:
   • Play / Pause / Stop: Standard controls to watch your reversed video
   • Frame-by-Frame: Use << Frame or Frame >> to jump backwards or forwards by one frame at a time
   • Playback Speed: Adjust the slider (0.1x up to 3x)
   • Keeping the reversed video: Check or uncheck "Do not delete reversed video" if you want the final reversed .mp4 file to remain when you close the app

Detailed Explanation of Functions

load_config() and save_config(cfg)

• Handles loading and saving user preferences (e.g., chosen temp folder, whether to keep reversed videos) in a local settings.json

get_available_formats(url)

• Uses yt_dlp to fetch the video's available formats up to 1024p
• Returns a list of (height, format_id)

download_video(url, format_id, output_path, progress_callback)

• Downloads the specified format to output_path
• Uses a progress_callback to report download percentage in real time

two_step_reverse_and_fps(in_path, out_path, user_fps, progress_callback)

• Calls FFmpeg in two steps:
  1. Reverse and reset timestamps
  2. Encode to desired user_fps
• No audio is retained, as this script is primarily for reversing the visuals

VLCPlayerApp (the main GUI class)

• Manages the Tkinter UI, VLC playback, timeline updates, and user interactions:
  • on_refresh_info() → Fetch available resolutions
  • on_generate() → Download & reverse video
  • on_play(), on_pause(), on_stop() → Playback controls
  • on_prev_frame(), on_next_frame() → Frame-by-frame stepping
  • on_speed_change() → Changes playback rate in real time
  • on_close() → Cleanup (temp folders, config save, etc.)

Known Limitations

• No audio is retained in the reversed output
• High resolutions above 1024p are skipped by default (you can modify the code if you want higher resolutions)
• VLC may occasionally have trouble with certain exotic codecs or unrecognized container formats. Try a different resolution if that happens
• The FFmpeg encoding parameters are optimized for processing speed rather than output quality - if you need higher quality output, you may want to modify the encoding parameters in the two_step_reverse_and_fps function

FAQ

Q: Do I need VLC in my PATH environment variable?
A: Typically, no. If you installed VLC with the default settings, python-vlc should find it automatically. If you installed VLC in a non-standard location, you may need to copy libvlc.dll and plugins/ into the same folder as this script or reinstall VLC to its default location.

Q: What if ffmpeg is not found?
A: Install FFmpeg or copy its executable into the project folder. If on Windows, ensure ffmpeg.exe is in the same folder or in your PATH. Tutorial : tutorial

Q: Can I keep the reversed .mp4 file permanently?
A: Yes—check the box "Do not delete reversed video" in the app. Otherwise, it's deleted when you close the program.

Q: What if I get an error about libvlc or python-vlc?
A: Make sure you installed the normal VLC player. Reinstall or place libvlc.dll in this folder.

License

This project is distributed under the MIT License. See LICENSE for details.

Happy reversing! If you run into issues, please open an issue or feel free to submit a PR.