Timeline Package (timeline)

The timeline package provides the declarative Abstract Syntax Tree (AST) representing video compositions.

Timeline

import "github.com/farshidrezaei/vidonex/timeline"

tl := timeline.New(
    timeline.WithCanvas(types.Size{Width: 1920, Height: 1080}),
    timeline.WithFPS(types.FPS60),
    timeline.WithBackgroundColor(types.Black),
)

Methods

• tl.AddTrack(tracks ...*Track) *Timeline: Appends tracks to the timeline.
• tl.Tracks() iter.Seq[*Track]: Modern Go iterator over all registered tracks.
• tl.Validate() error: Verifies timeline consistency, media duration constraints, and stream alignment.

---

Tracks

track := timeline.NewTrack("main_video", timeline.TrackKindVideo).
    SetZIndex(0)

Track Kinds

• TrackKindVideo: Primary background or normalized video stream.
• TrackKindOverlay: Picture-in-picture, alpha graphics, or animated layers.
• TrackKindAudio: Audio streams, music, or dialog.
• TrackKindSubtitle: Burned-in caption layers.
• TrackKindWaveform: Synthesized audio waveform visualizations.

---

Clips

clip := timeline.NewClip("clip_id", "path/to/media.mp4", 0, 10*time.Second).
    WithTrim(2*time.Second, 12*time.Second).
    WithScale(0.5).
    WithPosition(types.Point{X: 100, Y: 100}).
    WithOpacity(0.9).
    WithVolume(0.8)

Fluent Chaining Methods

• WithTrim(start, end time.Duration) *Clip: Sets source media in/out points.
• WithPosition(point types.Point) *Clip: Coordinates on canvas.
• WithScale(factor float64) *Clip: Scale multiplier.
• WithOpacity(alpha float64) *Clip: Transparency 0.0 (invisible) to 1.0 (solid).
• WithVolume(level float64) *Clip: Audio volume factor.