RecordRTC Audio into Ogg Chrome

[pitrackster]

Hi !

First thanks a lot for all the work done.

When I use RecordRTC demo in Chrome (v 43.0.2357.81 - 64bits) with Audio into OGG selected, the downloaded file is in WAV format.

Is that normal ? Is it possible to record audio in OGG with Chrome ?

I tried to set the options like this :

var options = {
    mimeType : 'audio/ogg',
    bitsPerSecond: 128000
};

But this is not working...

Regards

[muaz-khan]

MediaRecorder API are implemented in Chrome DEV/CANARY, but that API currently supporting only video-recording. Audio-recording is work-in-progress.

Also, MediaRecorder API in Chrome are still behind a flag.

Here is an alternative solution for converting WAV into Ogg: https://github.com/muaz-khan/Ffmpeg.js/blob/master/wav-to-ogg.html

[pitrackster]

Hi Muaz-Khan !

Thank you very much for your reply.
I've seen the ffmpeg.js librarie, but it's size (18Mb) makes it not very usefull in my context...

I'll take a look at Chrome Dev/Canary to see if they scheduled a date for AudioRecording support.

Thanks again!

[amallecourt]

Is it still not supported in Chrome today ?
I didn't manage to do it.

[muaz-khan]

Regarding CODECS:

• Chrome supports VP9+VP8 along with opus vorbis audio (48kHz). PS: H.264 coming soon.
• Firefox supports VP8 along with opus vorbis audio (44.1 kHz).

Regarding CONTAINER_FORMATS,

• Chrome supports audio/webm, video/webm, video/webm;codecs=vp8 and video/webm;codecs=vp9
• Firefox supports audio/webm, audio/ogg, video/webm, video/mp4 and video/webm;codecs=vp8

Regarding BITRATES:

• Chrome supports opus_MIN 6kbps and opus_MAX 128kbps
• Chrome supports VPX_MIN 100kbps and no max limit
• Firefox supports VPX_default 2.5Mbps however audio default is adaptive dependant on the sample rate and number of audio channels

---

So you'll always get audio/webm in Chrome rather than audio/ogg. You can change the file-extension (mp3/ogg) or file-type (audio/mp3 or audio/ogg) however Audio_RAW_DATA headers will be using audio/webm

---

Nowadays both Chrome+Firefox are accepting audioBitsPerSecond, videoBitsPerSecond as well as bitsPerSecond optional values (as 2nd-parameter over MediaRecorder API).

[amallecourt]

Ok, thanks.
But now I wonder what is the best way to have a compressed (or minimum size) audio file with recordRTC in Chrome ? What do you think about it ? Because I would like to record conferences which can last more than 1 hour. After 20 minutes of recording, the wav file is already way to large and the browser can't manage it. If I record it, and then compress it, it takes too much time for a userfriendly experience. (I already affected numberOfAudioChannels to 1)

[thijstriemstra]

You could also use libvorbis.js if you're recording audio-only.

[hexadecy]

Tested on

Windows 10 + Chrome 55 and Firefox 50

Media Stream options

type: "audio"

As a workaround change that part in RecordRTC.js

Firefox will record in audio/ogg
Chrome will record in audio/webm

function GetRecorderType(mediaStream, config) {    
//...
    if (isMediaRecorderCompatible() && recorder !== CanvasRecorder && recorder !== GifRecorder && typeof MediaRecorder !== 'undefined' && 'requestData' in MediaRecorder.prototype) {
        if (mediaStream.getVideoTracks().length || (mediaStream.getAudioTracks().length && MediaRecorder.isTypeSupported('audio/webm'))) {
        recorder = MediaStreamRecorder;
        }
    }
//...

Pull request

How many previous version we want to support in this lib? Chrome 46, 47-48, 49.... ?
I think it's better to check for MediaRecorder type support than specific version of Chrome like version 49 in isMediaRecorderCompatible().
ref: https://developer.mozilla.org/en-US/docs/Web/API/MediaRecorder/isTypeSupported

[Chauncy-Chen]

audio/webm

Do you know how to record audio/webm format in Firefox