Duration is zero

[assada]

let stream = audioCtx.createMediaStreamDestination();
// ...play some audio to stream...
let recorder = new MediaRecorder(stream);
recorder.start();
recorder.addEventListener('dataavailable', function (e) {
    saveBlob(e.data, 'sample.wav');
});

Result: playable as normal media file but with 0 duration

Its posible to get ogg/wav format instead webm?

[assada]

Haha! I forgot to add { mimeType: 'audio/wav' } option to media recorder! After that its works awesome!

sorry for the hasty issue...

[chrisguttandin]

No problem. I'm glad you got it working.