Split-Screen Video Grid Builder is a desktop multi-video collage, side-by-side comparison, picture-in-picture, and 2x2 quad-grid compositor for Linux powered by a bundled FFmpeg engine. An independent Linux alternative to Wondershare Filmora's split-screen video layout tools, it combines 2, 3, or 4 video clips into clean MP4 or MKV videos with customizable divider borders, audio track mixing or selection, and live frame layout previews.

Key Features:

• 7 Multi-Video Filtergraph Layouts: Combine 2 videos in Side-by-Side (hstack), Top-Bottom (vstack), or Picture-in-Picture (overlay); 3 videos in Hero-Left, Top-Banner, or Triple Columns; and 4 videos in a 2x2 Quad Grid (xstack).
• Customizable Divider Borders & Cell Framing: Choose pixel-exact divider width (0 to 24 px), custom RGB hex border colors, Center-Crop Fill or Letterbox Pad cell framing, and 16:9, 1:1 Square, or 9:16 Vertical output canvases.
• Multi-Track Audio Mixing & Solo Selection: Mix all active input audio streams via amix, solo an individual clip's audio track with gain control, or export silent video collages.
• Live FFmpeg Frame Preview & Filtergraph Inspector: Preview the exact composited frame at any timestamp before encoding, inspect input stream codecs and bitrates, and export MP4 or MKV files with real-time progress tracking.

Disclaimer: This project is an independent open-source tool and is not affiliated with, sponsored by, or endorsed by Wondershare.