AudioContext: createMediaStreamTrackSource() method
The createMediaStreamTrackSource()
method of the AudioContext
interface creates and returns a MediaStreamTrackAudioSourceNode
which represents an audio source whose data comes from the specified MediaStreamTrack
.
This differs from createMediaStreamSource()
, which creates a MediaStreamAudioSourceNode
whose audio comes from the audio track in a specified MediaStream
whose id
is first, lexicographically (alphabetically).
Syntax
createMediaStreamTrackSource(track)
Parameters
track
-
The
MediaStreamTrack
to use as the source of all audio data for the new node.
Return value
A MediaStreamTrackAudioSourceNode
object which acts as a source for
audio data found in the specified audio track.
Examples
In this example, getUserMedia()
is used to
request access to the user's microphone. Once that access is attained, an audio context
is established and a MediaStreamTrackAudioSourceNode
is created using
createMediaStreamTrackSource()
, taking its audio from the first audio track
in the stream returned by getUserMedia()
.
Then a BiquadFilterNode
is created using
createBiquadFilter()
, and it's
configured as desired to perform a lowshelf filter on the audio coming from the source.
The output from the microphone is then routed into the new biquad filter, and the
filter's output is in turn routed to the audio context's
destination
.
navigator.mediaDevices
.getUserMedia({ audio: true, video: false })
.then((stream) => {
audio.srcObject = stream;
audio.onloadedmetadata = (e) => {
audio.play();
audio.muted = true;
};
const audioCtx = new AudioContext();
const audioTracks = stream.getAudioTracks();
const source = audioCtx.createMediaStreamTrackSource(audioTracks[0]);
const biquadFilter = audioCtx.createBiquadFilter();
biquadFilter.type = "lowshelf";
biquadFilter.frequency.value = 3000;
biquadFilter.gain.value = 20;
source.connect(biquadFilter);
biquadFilter.connect(audioCtx.destination);
})
.catch((err) => {
// Handle getUserMedia() error
});
Specifications
Specification |
---|
Web Audio API # dom-audiocontext-createmediastreamtracksource |
Browser compatibility
BCD tables only load in the browser
See also
- Web Audio API
- Using the Web Audio API
MediaStreamTrackAudioSourceNode