VideoTools/docs/COMPARE_FULLSCREEN.md

Compare Module - Fullscreen Mode

Overview

The Compare module now includes a Fullscreen Compare mode that displays two videos side-by-side in a larger view, optimized for detailed visual comparison.

Features

Current (v0.1)

• ✅ Side-by-side fullscreen layout
• ✅ Larger video players for better visibility
• ✅ Individual playback controls for each video
• ✅ File labels showing video names
• ✅ Back button to return to regular Compare view
• ✅ Pink colored header/footer matching Compare module

Planned (Future - requires VT_Player enhancements)

• ⏳ Synchronized playback - Play/Pause both videos simultaneously
• ⏳ Linked seeking - Seek to same timestamp in both videos
• ⏳ Frame-by-frame sync - Step through both videos in lockstep
• ⏳ Volume link - Adjust volume on both players together
• ⏳ Playback speed sync - Change speed on both players at once

Usage

Accessing Fullscreen Mode

1. Load two videos in the Compare module
2. Click the "Fullscreen Compare" button
3. Videos will display side-by-side in larger players

Controls

• Individual players: Each video has its own play/pause/seek controls
• "Play Both" button: Placeholder for future synchronized playback
• "Pause Both" button: Placeholder for future synchronized pause
• "< BACK TO COMPARE": Return to regular Compare view

Use Cases

Visual Quality Comparison

Compare encoding settings or compression quality:

• Original vs. compressed
• Different codec outputs
• Before/after color grading
• Different resolution scaling

Frame-Accurate Comparison

When VT_Player sync is implemented:

• Compare edits side-by-side
• Check for sync issues in re-encodes
• Validate frame-accurate cuts
• Compare different filter applications

A/B Testing

Test different processing settings:

• Different deinterlacing methods
• Upscaling algorithms
• Noise reduction levels
• Color correction approaches

Technical Notes

Current Implementation

• Uses standard buildVideoPane() for each side
• 640x360 minimum player size (scales with window)
• Independent playback state per video
• No shared controls between players yet

VT_Player API Requirements for Sync

For synchronized playback, VT_Player will need:

// Playback state access
player.IsPlaying() bool
player.GetPosition() time.Duration

// Event callbacks
player.OnPlaybackStateChanged(callback func(playing bool))
player.OnPositionChanged(callback func(position time.Duration))

// Synchronized control
player.SyncWith(otherPlayer *Player)
player.Unsync()

Synchronization Strategy

When VT_Player supports it:

1. Master-Slave Pattern: One player is master, other follows
2. Linked Events: Play/pause/seek events trigger on both
3. Position Polling: Periodically check for drift and correct
4. Frame-Accurate Sync: Step both players frame-by-frame together

Keyboard Shortcuts (Planned)

When implemented in VT_Player:

• Space - Play/Pause both videos
• J / L - Rewind/Forward both videos
• ← / → - Step both videos frame-by-frame
• K - Pause both videos
• 0-9 - Seek to percentage (0% to 90%) in both
• Esc - Exit fullscreen mode

UI Layout

┌─────────────────────────────────────────────────────────────┐
│ < BACK TO COMPARE                                            │ ← Pink header
├─────────────────────────────────────────────────────────────┤
│                                                              │
│  Side-by-side fullscreen comparison. Use individual...      │
│                                                              │
│        [▶ Play Both]  [⏸ Pause Both]                        │
│  ─────────────────────────────────────────────────────────  │
│                                                              │
│  ┌─────────────────────────┬─────────────────────────────┐  │
│  │   File 1: video1.mp4    │   File 2: video2.mp4        │  │
│  ├─────────────────────────┼─────────────────────────────┤  │
│  │                         │                             │  │
│  │    Video Player 1       │    Video Player 2           │  │
│  │    (640x360 min)        │    (640x360 min)            │  │
│  │                         │                             │  │
│  │  [Play] [Pause] [Seek]  │  [Play] [Pause] [Seek]      │  │
│  │                         │                             │  │
│  └─────────────────────────┴─────────────────────────────┘  │
│                                                              │
└─────────────────────────────────────────────────────────────┘
                                                          ← Pink footer

Future Enhancements

v0.2 - Synchronized Playback

• Implement master-slave sync between players
• Add "Link" toggle button to enable/disable sync
• Visual indicator when players are synced

v0.3 - Advanced Sync

• Offset compensation (e.g., if videos start at different times)
• Manual sync adjustment (nudge one video forward/back)
• Sync validation indicator (shows if videos are in sync)

v0.4 - Comparison Tools

• Split-screen view with adjustable divider
• A/B quick toggle (show only one at a time)
• Difference overlay (highlight changed regions)
• Frame difference metrics display

Notes

• Fullscreen mode is accessible from regular Compare view
• Videos must be loaded before entering fullscreen mode
• Synchronized controls are placeholders until VT_Player API is enhanced
• Window can be resized freely - players will scale
• Each player maintains independent state for now