Legacy Documentation: Version 2018.2 (Go to current version)
  • C#


Suggest a change


Thank you for helping us improve the quality of Unity Documentation. Although we cannot accept all submissions, we do read each suggested change from our users and will make updates where applicable.


Submission failed

For some reason your suggested change could not be submitted. Please <a>try again</a> in a few minutes. And thank you for taking the time to help us improve the quality of Unity Documentation.



Switch to Manual
public void PlayScheduled(double time);


timeTime in seconds on the absolute time-line that AudioSettings.dspTime refers to for when the sound should start playing.


Plays the clip at a specific time on the absolute time-line that AudioSettings.dspTime reads from.

This is the preferred way to stitch AudioClips in music players because it is independent of the frame rate and gives the audio system enough time to prepare the playback of the sound to fetch it from media where the opening and buffering takes a lot of time (streams) without causing sudden CPU spikes.

using UnityEngine;
using System.Collections;

// Basic demonstration of a music system that uses PlayScheduled to preload and sample-accurately // stitch two AudioClips in an alternating fashion. The code assumes that the music pieces are // each 16 bars (4 beats / bar) at a tempo of 140 beats per minute. // To make it stitch arbitrary clips just replace the line // nextEventTime += (60.0 / bpm) * numBeatsPerSegment // by // nextEventTime += clips[flip].length;

[RequireComponent(typeof(AudioSource))] public class ExampleClass : MonoBehaviour { public float bpm = 140.0f; public int numBeatsPerSegment = 16; public AudioClip[] clips = new AudioClip[2];

private double nextEventTime; private int flip = 0; private AudioSource[] audioSources = new AudioSource[2]; private bool running = false;

void Start() { for (int i = 0; i < 2; i++) { GameObject child = new GameObject("Player"); child.transform.parent = gameObject.transform; audioSources[i] = child.AddComponent<AudioSource>(); }

nextEventTime = AudioSettings.dspTime + 2.0f; running = true; }

void Update() { if (!running) { return; }

double time = AudioSettings.dspTime;

if (time + 1.0f > nextEventTime) { // We are now approx. 1 second before the time at which the sound should play, // so we will schedule it now in order for the system to have enough time // to prepare the playback at the specified time. This may involve opening // buffering a streamed file and should therefore take any worst-case delay into account. audioSources[flip].clip = clips[flip]; audioSources[flip].PlayScheduled(nextEventTime);

Debug.Log("Scheduled source " + flip + " to start at time " + nextEventTime);

// Place the next event 16 beats from here at a rate of 140 beats per minute nextEventTime += 60.0f / bpm * numBeatsPerSegment;

// Flip between two audio sources so that the loading process of one does not interfere with the one that's playing out flip = 1 - flip; } } }

The example at AudioSource.SetScheduledEndTime shows how you can play two audio clips without pops or clicks between the clips. The approach is to have two AudioSources with clips attached, and queue up each clip using its AudioSource.

See Also: SetScheduledStartTime.

Did you find this page useful? Please give it a rating: