Allows visual verification of detected scene changes before accepting.
Features:
- Extracts thumbnail at each detected chapter timestamp
- Displays first 24 chapters in scrollable grid (4 columns)
- Shows timestamp below each thumbnail (160x90px previews)
- Accept/Reject buttons to confirm or discard detection
- Progress indicator during thumbnail generation
Implementation:
- showChapterPreview() function creates preview dialog
- extractChapterThumbnail() uses FFmpeg to extract frame
- Scales to 320x180, saves as JPEG in temp dir
- Thumbnails generated in background, dialog updated when ready
Performance:
- Limits to 24 chapters for UI responsiveness
- Shows "(showing first 24)" if more detected
- Temp files stored in videotools-chapter-thumbs/
User workflow:
1. Adjust sensitivity slider
2. Click "Detect Scenes"
3. Review thumbnails to verify detection quality
4. Accept to use chapters, or Reject to try different sensitivity
Problem: Author log was causing severe UI lag and memory issues
- Unbounded string growth (entire log kept in RAM)
- Full widget rebuild on every line append
- O(n²) string concatenation performance
Solutions implemented:
1. Tail behavior - Keep only last 100 lines in UI
- Uses circular buffer (authorLogLines slice)
- Prevents unbounded memory growth
- Rebuilds text from buffer on each append
2. Copy Log button
- Copies full log from file (accurate)
- Falls back to in-memory log if file unavailable
3. View Full Log button
- Opens full log in dedicated log viewer
- No UI lag from large logs
4. Track log file path
- authorLogFilePath stored when log created
- Used by copy and view buttons
Performance improvements:
- Memory: O(1) instead of O(n) - fixed 100 line buffer
- CPU: One SetText() per line instead of concatenation
- UI responsiveness: Dramatically improved with tail behavior
UI changes:
- Label shows "Authoring Log (last 100 lines)"
- Copy/View buttons for accessing full log
DVD Authoring Fix:
- Add remultiplex step after MPEG encoding for DVD compliance
- Use ffmpeg -fflags +genpts -c copy -f dvd to fix timestamps
- Resolves "ERR: SCR moves backwards" error from dvdauthor
- FFmpeg direct encoding doesn't always create DVD-compliant streams
- Remux regenerates presentation timestamps correctly
Queue Animation Fix:
- Stop stripe animation on completed jobs
- Bug: Refresh() was always incrementing offset regardless of state
- Now only increments offset when animStop != nil (animation running)
- Completed/failed/cancelled jobs no longer show animated stripes
Testing:
- DVD authoring should now succeed on AVI files
- Completed queue jobs should show static progress bar
- Current state: 3 modules partially/fully extracted
- upscale_module.go: showUpscaleView + AI helpers migrated successfully
- Build syntax: ✅ Clean
- Build failing due to unrelated Fyne API issue in internal/ui/queueview.go
- Ready for next incremental extraction steps
