docs/features/assa-apply-advanced-effects.md
Apply cinematic and creative ASS/SSA override tag effects to subtitles with real-time video preview.
This feature automatically generates complex ASSA override tag animations and effects for selected subtitle lines. Each effect creates frame-by-frame animations using ASSA's vector drawing and animation capabilities, with real-time video preview.
Effects range from text animations (typewriter, karaoke, bounce-in) to visual enhancements (neon, glitch, rainbow) to transitions and atmospheric/background generators (starfield, rain, snow, fireflies, old movie, confetti, hearts).
Note: Audio-reactive effects (like Audio text pulse) are only shown when waveform/audio peak data is available.
| Effect | Description |
|---|---|
| Typewriter | Characters appear one-by-one as if being typed |
| Typewriter with highlight | Characters appear one-by-one with a glowing highlight on the active character |
| Word by word | Words appear one-by-one instead of characters |
| Karaoke | Classic karaoke color-wipe effect synchronized to subtitle timing |
| Scramble reveal | Text starts scrambled and gradually resolves to the correct characters |
| Bounce in | Each character springs in with an elastic pop animation |
| Effect | Description |
|---|---|
| Neon burst | Text appears with a neon glow and "pop" animation using modern colors |
| Rainbow pulse | Text cycles through rainbow colors with a pulsing animation |
| Wave | Text characters undulate in a wave motion |
| Wave (blue) | Blue/cyan wave variant |
| Glitch | Digital glitch overlays with flashes, distortion, and chromatic offset |
| Audio text pulse | Audio-reactive glow/scale pulse driven by waveform amplitude |
| Effect | Description |
|---|---|
| Transition - fade-in | Per-line fade-in from black at the start of each subtitle |
| Transition - fade-out | Per-line fade-out to black at the end of each subtitle |
| Effect | Description |
|---|---|
| Star Wars scroll | Classic opening crawl effect with perspective text scrolling into the distance |
| Credits scroll | Vertical scrolling credits effect |
| Infinite starfield (background) | Continuous warp-speed starfield background |
| Infinite rain (background) | Continuous falling rain with depth layers |
| Infinite snow (background) | Continuous snowfall with depth layers |
| Fireflies (background) | Warm glowing dots drifting and pulsing organically |
| Old movie effect (background) | Film grain, scratches, gate flicker, and vignette |
| Matrix | Falling green character rain with matrix-style subtitle reveal |
| Confetti burst | Colorful spinning confetti bursts from dynamic launch points |
| Hearts (rain) | Bezier-drawn hearts rain gently with tumbling motion |
Applies the effect to every subtitle line in the file.
Applies the effect only to the currently selected subtitle lines. Useful for applying effects to specific scenes or sections.
Applies the effect starting from the first selected line through to the end of the subtitle file.
The video player shows a live preview of the selected effect as you change options. The effect is rendered using a temporary ASS file and displayed over the video using libmpv's subtitle rendering.
Each effect generates ASSA override tags ({\tag}) to animate properties like:
\pos, \move)\fscx, \fscy)\frx, \fry, \frz)\1c, \3c, \4c)\alpha, \1a, \3a, \4a)\blur)\bord)\t(...))\p1, drawing commands)Many effects split a single subtitle line into multiple lines with sequential timing to create frame-by-frame animation.
Effects that involve positioning or drawing (background effects, particles, transitions) adapt to the video resolution. The feature automatically detects the video dimensions or uses a fallback resolution of 1280x720.
| Key | Action |
|---|---|
| Escape | Close without applying |