A clean 1‑L index makes the AVI act like a modern container (e.g., MP4) while preserving the original video quality. 2. Preparing Your Workspace | Step | Action | |------|--------| | 2.1 | Back up the original file. Use a separate drive or folder ( Jack_Giant_Slayer_original.avi ). | | 2.2 | Install FFmpeg – the most reliable, cross‑platform tool for re‑indexing. Windows: Download from https://ffmpeg.org/download.html and add ffmpeg.exe to your PATH . macOS: brew install ffmpeg Linux: sudo apt‑get install ffmpeg | | 2.3 | (Optional) Install Avidemux or VirtualDub if you prefer a GUI. | | 2.4 | Verify the file with MediaInfo ( mediainfo Jack_Giant_Slayer.avi ). Note codec, resolution, and current index status. | 3. Re‑Generating the AVI Index – The FFmpeg Way 3.1. Basic One‑Line Command ffmpeg -i Jack_Giant_Slayer.avi -c copy -map 0 -fflags +genpts -movflags faststart Jack_Giant_Slayer_fixed.avi Explanation of flags