Members
(static) levelAnalyserNativeInterval :Number
- Source:
The Native interval for the AudioHelper to analyse audio levels from streams Any interval passed to startLevelReports() would need to be a multiple of this value. Defaults to 50ms.
Type:
_analyserInterval :Number
- Source:
Interval ID as returned by setInterval for analysing the volume of streams When set to 0, means no timer is set.
Type:
_analyserStreams :Object
- Source:
Map of all streams that we listen to for determining the decibel levels. Used for analyzing audio levels of each stream. Format of the object stored is : {id: { stream: MediaStream, analyser: AudioAnalyser, interval: Number, callback: Function } }
Type:
- Object
_audioContext :AudioContext
- Source:
Audio Context singleton used for analysing audio levels of each stream Only created if necessary to listen to audio streams.
Type:
- AudioContext
_fftArray :Float32Array
- Source:
Fast Fourrier Transform Array. Used for analysing the decibel level of streams. The array is allocated only once then filled by the analyser repeatedly. We only generate it when we need to listen to a stream's level, so we initialize it to null.
Type:
- Float32Array
locked :Boolean
- Source:
A flag for whether video playback is currently locked by awaiting a user gesture
Type:
- Boolean
pending :Array
- Source:
A user gesture must be registered before audio can be played. This Array contains the Howl instances which are requested for playback prior to a gesture. Once a gesture is observed, we begin playing all elements of this Array.
Type:
sounds :Object
- Source:
The set of Howl instances which have been created for different audio paths
Type:
- Object
Methods
(static) inputToVolume(value, order) → {number}
- Source:
Returns the volume value based on a range input volume control's position. This is using an exponential approximation of the logarithmic nature of audio level perception Based on https://www.dr-lex.be/info-stuff/volumecontrols.html We're using x^3 by default instead of x^4 otherwise the audio becomes nearly silent around the 40% mark.
Parameters:
| Name | Type | Default | Description |
|---|---|---|---|
value |
number | string | Value between [0, 1] of the range input |
|
order |
number |
2
|
[optional] the exponent of the curve (default: 2) |
Returns:
- Type
- number
(static) play(data, pushopt) → {Howl}
- Source:
Play a one-off sound effect which is not part of a Playlist
Example
// Play the sound of a locked door for all players
Audio.play({src: "sounds/lock.wav", volume: 0.8, autoplay: true, loop: false}, true);Parameters:
| Name | Type | Attributes | Description | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
data |
Object | An object configuring the audio data to play Properties
|
||||||||||||||||
push |
Boolean |
<optional> |
Push the audio sound effect to other connected clients? |
Returns:
A Howl instance which controls audio playback.
- Type
- Howl
(static) preload(data)
- Source:
Create a Howl object and load it to be ready for later playback
Parameters:
| Name | Type | Description |
|---|---|---|
data |
Object | The audio data to preload |
(static) registerSettings()
- Source:
Register client-level settings for global volume overrides
(static) volumeToInput(volume, order) → {number}
- Source:
Counterpart to inputToVolume() Returns the input range value based on a volume
Parameters:
| Name | Type | Default | Description |
|---|---|---|---|
volume |
number | Value between [0, 1] of the volume level |
|
order |
number |
2
|
[optional] the exponent of the curve (default: 2) |
Returns:
- Type
- number
_onFirstGesture(event)
- Source:
Handle the first observed user gesture
Parameters:
| Name | Type | Description |
|---|---|---|
event |
Event | The mouse-move event which enables playback |
awaitFirstGesture()
- Source:
Register an event listener to await the first mousemove gesture and begin playback once observed
create(src, preload, autoplay) → {Howl}
- Source:
Create a Howl instance
Parameters:
| Name | Type | Description |
|---|---|---|
src |
||
preload |
||
autoplay |
Returns:
- Type
- Howl
getAudioContext() → {AudioContext}
- Source:
Returns a singleton AudioContext if one can be created. An audio context may not be available due to limited resources or browser compatibility in which case null will be returned
Returns:
A singleton AudioContext or null if one is not available
- Type
- AudioContext
play(src, id)
- Source:
Play a single audio effect by it's source path and Howl ID
Parameters:
| Name | Type | Description |
|---|---|---|
src |
String | |
id |
Number |
startLevelReports(id, stream, callback, interval, smoothing) → {boolean}
- Source:
Registers a stream for periodic reports of audio levels. Once added, the callback will be called with the maximum decibel level of the audio tracks in that stream since the last time the event was fired. The interval needs to be a multiple of AudioHelper.levelAnalyserNativeInterval which defaults at 50ms
Parameters:
| Name | Type | Default | Description |
|---|---|---|---|
id |
string | An id to assign to this report. Can be used to stop reports |
|
stream |
MediaStream | The media stream to report on its audio tracks |
|
callback |
function | The callback function to call with the decibel level. |
|
interval |
number |
50
|
(optional) The interval at which to produce reports. |
smoothing |
number |
0.1
|
(optional) The smoothingTimeConstant to set on the audio analyser. Refer to AudioAnalyser API docs. |
Returns:
Returns whether or not listening to the stream was successful
- Type
- boolean
stopLevelReports(id)
- Source:
Stop sending audio level reports This stops listening to a stream and stops sending reports. If we aren't listening to any more streams, cancel the global analyser timer.
Parameters:
| Name | Type | Description |
|---|---|---|
id |
string | The id of the reports that passed to startLevelReports. |