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Class: AudioManager

Defined in: src/core/AudioManager.ts:91

Manages audio playback synchronized with the manim-web Scene timeline.

Usage:

const audio = new AudioManager();
await audio.addSound('/sounds/click.wav', { time: 0.5 });
audio.play();             // start playback
audio.seek(2.0);          // jump to 2 s
const wav = await audio.exportWAV();

Constructors​

Constructor​

new AudioManager(): AudioManager

Returns​

AudioManager

Accessors​

context​

Get Signature​

get context(): AudioContext

Defined in: src/core/AudioManager.ts:136

Get the underlying AudioContext (creates one if needed).

Returns​

AudioContext

isPlaying​

Get Signature​

get isPlaying(): boolean

Defined in: src/core/AudioManager.ts:356

Whether audio is currently playing.

Returns​

boolean

tracks​

Get Signature​

get tracks(): readonly AudioTrack[]

Defined in: src/core/AudioManager.ts:349

Get a readonly copy of the current track list.

Returns​

readonly AudioTrack[]

Methods​

addSound()​

addSound(url, options): Promise<AudioTrack>

Defined in: src/core/AudioManager.ts:175

Add a sound to the timeline.

Parameters​

url​

string

URL of the audio file

options​

AddSoundOptions = {}

Scheduling and playback options

Returns​

Promise<AudioTrack>

The created AudioTrack (buffer may still be loading)

addSoundAtAnimation()​

addSoundAtAnimation(animation, url, options): Promise<AudioTrack>

Defined in: src/core/AudioManager.ts:208

Add a sound that starts when a given animation begins on the timeline.

The animation must already be scheduled (i.e. have a non-null startTime). If the animation has not been scheduled yet, time falls back to 0.

Parameters​

animation​

Animation

Animation whose start time to sync with

url​

string

URL of the audio file

options​

Omit<AddSoundOptions, "time"> & object = {}

Additional options (time is overridden by animation)

Returns​

Promise<AudioTrack>

The created AudioTrack

clearTracks()​

clearTracks(): void

Defined in: src/core/AudioManager.ts:339

Remove all tracks and stop playback.

Returns​

void

connectOutput()​

connectOutput(node): void

Defined in: src/core/AudioManager.ts:462

Connect the master output to an external node (for example an AnalyserNode used for audio-reactive visualization). The node keeps receiving the mixed output until the context is closed.

Parameters​

node​

AudioNode

The destination node to feed from the master gain

Returns​

void

createStreamDestination()​

createStreamDestination(): MediaStreamAudioDestinationNode

Defined in: src/core/AudioManager.ts:448

Get an AudioNode destination suitable for muxing with a MediaRecorder. This creates a MediaStreamAudioDestinationNode that can be combined with a video stream for video+audio export.

Returns​

MediaStreamAudioDestinationNode

MediaStreamAudioDestinationNode connected to the master gain

dispose()​

dispose(): void

Defined in: src/core/AudioManager.ts:532

Release all audio resources.

Returns​

void

exportWAV()​

exportWAV(duration?, sampleRate?): Promise<Blob>

Defined in: src/core/AudioManager.ts:436

Export all audio tracks as a WAV Blob.

Parameters​

duration?​

number

Total duration (seconds). Defaults to getDuration().

sampleRate?​

number = 44100

Sample rate. Defaults to 44100.

Returns​

Promise<Blob>

WAV Blob

getCurrentTime()​

getCurrentTime(): number

Defined in: src/core/AudioManager.ts:279

Get the current playback position on the timeline (seconds).

Returns​

number

getDuration()​

getDuration(): number

Defined in: src/core/AudioManager.ts:363

Get the total duration of the audio timeline (end of the latest track).

Returns​

number

loadBuffer()​

loadBuffer(url): Promise<AudioBuffer>

Defined in: src/core/AudioManager.ts:149

Load and decode an audio file, with caching.

Parameters​

url​

string

URL of the audio resource

Returns​

Promise<AudioBuffer>

Decoded AudioBuffer

mixdown()​

mixdown(duration?, sampleRate?): Promise<AudioBuffer>

Defined in: src/core/AudioManager.ts:383

Render all audio tracks into a single stereo AudioBuffer (offline).

Parameters​

duration?​

number

Total duration to render (seconds). Defaults to getDuration().

sampleRate?​

number = 44100

Output sample rate. Defaults to 44100.

Returns​

Promise<AudioBuffer>

Mixed-down AudioBuffer

pause()​

pause(): void

Defined in: src/core/AudioManager.ts:239

Pause audio playback, remembering the current position.

Returns​

void

play()​

play(): void

Defined in: src/core/AudioManager.ts:225

Start (or resume) audio playback from the current position.

Returns​

void

removeTrack()​

removeTrack(trackId): void

Defined in: src/core/AudioManager.ts:321

Remove a track by id.

Parameters​

trackId​

number

Returns​

void

seek()​

seek(time): void

Defined in: src/core/AudioManager.ts:254

Seek to an absolute time on the timeline (seconds). If currently playing, audio restarts from the new position.

Parameters​

time​

number

Returns​

void

setGlobalGain()​

setGlobalGain(value): void

Defined in: src/core/AudioManager.ts:292

Set the master output volume.

Parameters​

value​

number

Gain value (0 = silent, 1 = unity)

Returns​

void

setTrackGain()​

setTrackGain(trackId, value): void

Defined in: src/core/AudioManager.ts:304

Set the gain for a specific track.

Parameters​

trackId​

number

Track identifier

value​

number

Gain value (0 = silent, 1 = unity)

Returns​

void

stop()​

stop(): void

Defined in: src/core/AudioManager.ts:270

Stop playback and reset to the beginning.

Returns​

void

audioBufferToWAV()​

static audioBufferToWAV(buffer): Blob

Defined in: src/core/AudioManager.ts:474

Encode an AudioBuffer as a WAV Blob (PCM 16-bit).

Parameters​

buffer​

AudioBuffer

Returns​

Blob