RenderGraphBuilder class

Builds the FFmpeg filter graph for a project.

Pure Dart (no plugins) so the graph can be unit tested. Every clip is normalised to the same canvas, frame rate and audio format before the concat, which is what keeps audio and video in sync across clips with different sources, speeds and missing audio streams.

Constructors

RenderGraphBuilder()

Properties

hashCode → int

The hash code for this object.

no setter, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toString() → String

A string representation of this object.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited

Static Methods

build({required List<VideoEditorClip> clips, required List<VideoEditorAudioTrack> audioTracks, required List<VideoEffectOverlay> effectOverlays, required Size canvas, required String outputPath, required List<String> videoCodecArgs, int fps = 30, List<RenderImageOverlay> imageOverlays = const [], String audioBitrate = '192k'}) → RenderPlan

buildSegment({required VideoEditorClip clip, required ClipTransition transitionIn, required ClipTransition transitionOut, required Size canvas, required String outputPath, required List<String> videoCodecArgs, int fps = 30}) → RenderPlan

Renders one clip, normalised exactly as in build, to a Matroska file with uncompressed audio. Preview segments are cached per clip and later joined with buildSegmentJoin without re-encoding the video; PCM audio avoids the AAC priming gaps that would otherwise build up at each join.

buildSegmentJoin({required String concatListPath, required Duration duration, required List<VideoEditorAudioTrack> audioTracks, required List<VideoEffectOverlay> effectOverlays, required String outputPath, required List<String> videoCodecArgs, int fps = 30, String audioBitrate = '96k'}) → RenderPlan

Joins cached segments listed in concatListPath (FFmpeg concat demuxer format) into the preview MP4. The video is copied as is unless timed effects need it re-encoded; the audio is re-timed, mixed with the audio tracks and encoded to AAC.

concatList(List<String> paths) → String

One line per segment for the FFmpeg concat demuxer.

segmentFrames(VideoEditorClip clip, int fps) → int

Frames of a preview segment for clip at fps (at least one).

transitionInAt(List<VideoEditorClip> clips, int i) → ClipTransition

Transition into clip i (none for the first clip).

transitionOutAt(List<VideoEditorClip> clips, int i) → ClipTransition

Transition out of clip i: the next clip's transition, if any.

transitionSeconds(ClipTransition transition, double clipSeconds) → double

Length in seconds of one side of transition on a clip that lasts clipSeconds; never more than a third of the clip.