New post-export step that multiplies the frame count by interpolating
between every consecutive frame pair. Supports 2x/4x/8x multipliers
using RIFE, FILM, or BiM-VFI methods.
- Add frame interpolation checkbox, multiplier combo (2x/4x/8x), and
method combo (RIFE/FILM/BiM-VFI) to Export Options group
- Implement _frame_interpolation_pass: works in log2(multiplier) passes,
each pass doubles frames by inserting midpoint interpolations
- Uses _fi_ temp prefix during rename to avoid filename collisions
- Preserves per-file extensions for mixed-format sequences
- Handles cancellation gracefully (renames temp files back)
- Runs after transition export, before optional video encoding
- Also clean up leftover _fi_ temp files in orphan removal
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
EthanfelandClaude Opus 4.6
7d7172e531