MediaStreamAudioSourceNode* AudioContext::createMediaStreamSource(MediaStream* mediaStream, ExceptionState& exceptionState)
{
ASSERT(isMainThread());
if (isContextClosed()) {
throwExceptionForClosedState(exceptionState);
return nullptr;
}
if (!mediaStream) {
exceptionState.throwDOMException(
InvalidStateError,
"invalid MediaStream source");
return nullptr;
}
MediaStreamTrackVector audioTracks = mediaStream->getAudioTracks();
if (audioTracks.isEmpty()) {
exceptionState.throwDOMException(
InvalidStateError,
"MediaStream has no audio track");
return nullptr;
}
// Use the first audio track in the media stream.
MediaStreamTrack* audioTrack = audioTracks[0];
OwnPtr<AudioSourceProvider> provider = audioTrack->createWebAudioSource();
MediaStreamAudioSourceNode* node = MediaStreamAudioSourceNode::create(this, mediaStream, audioTrack, provider.release());
// FIXME: Only stereo streams are supported right now. We should be able to accept multi-channel streams.
node->mediaStreamAudioSourceHandler().setFormat(2, sampleRate());
refNode(node); // context keeps reference until node is disconnected
return node;
}
