935617 - Opus audio playback is squeaky/garbled but G.711u is fine

Status: RESOLVED WORKSFORME

(Core :: WebRTC: Audio/Video, defect)

Description

[mpietras]

Attachment: OpusAudioSDP.txt

User Agent: Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/31.0.1650.39 Safari/537.36

Steps to reproduce:

Do getUserMedia; on mediaSuccess attach localStream, create RTCPeerConnection, createOffer; upon createOfferSuccess, setLocalDescription and await answer; upon answer, setRemoteDescription receive descriptionSuccess and media plays both directions (after ICE and DTLS-SRTP).  Opus is selected for both directions.  Opus FROM Firefox is fine.  Opus TO Firefox plays with high-pitched squeaks... like decode problems.  Identical code and flow works correctly in Chrome (also via DTLS-SRTP).  The actual Opus audio logged into a ogg.opus file plays fine in Firefox.  Identical code and flow works correctly when G.711u is selected.  SDP of both attached.  What else can I provide to help track this down?  Also tested in Nightly, same result.


Actual results:

Audio TO Firefox that plays in the local speakers is squeaky.  Sounds like a decode issue of some kind.  Audio FROM Firefox is fine.


Expected results:

Audio should sound fine both directions.

Comment 1

[mpietras]

Attachment: stream.opus is a ogg/opus packaged file of the actual data that was transmitted

Comment 2

[mpietras]

Attachment: sound_heard.mp3 is the recording of what Firefox is playing

Comment 3

[Randell Jesup [:jesup] (needinfo me)]

Logs obtained by setting NSPR_LOG_MODULES=signaling:5,audiostream:5,webrtc_trace:65535 NSPR_LOG_FILE=whatever WEBRTC_TRACE_FILE=another_file

Is all the audio 'squeaky'?  or squeaks imposed on the audio?  Speakerphone or headset (and the other end)?

Thanks!

(I'll listen to the audio shortly)

Comment 4

[mpietras]

Attachment: nspr.log of Opus bi-directional audio

Comment 5

[mpietras]

Attachment: webrtc_trace.log of Opus bi-directional audio

Comment 6

[mpietras]

Yes, all 'squeaky'... audio is unintelligible but it's not just straight noise; I can hear something CLOSE to what it's supposed to be... speakerphone (Logitech BCC950 specifically), although the microphone selection is somewhat independent from this problem as Firefox lets me choose the microphone device to share but uses the default speaker (some other device in my case) for output which is where the problem is occurring.


(In reply to Randell Jesup [:jesup] from comment #3)
> Logs obtained by setting
> NSPR_LOG_MODULES=signaling:5,audiostream:5,webrtc_trace:65535
> NSPR_LOG_FILE=whatever WEBRTC_TRACE_FILE=another_file
> 
> Is all the audio 'squeaky'?  or squeaks imposed on the audio?  Speakerphone
> or headset (and the other end)?
> 
> Thanks!
> 
> (I'll listen to the audio shortly)

Comment 7

[Virtual_ManPL [:Virtual] 🇵🇱 - (please needinfo? me - so I will see your comment/reply/question/etc.)]

Can you still reproduce it in latest Nightly in fresh clean new profile without any addons and plugins?

Comment 8

[mpietras]

I just tried it on Firefox 36 and it worked better.  By that I mean, it's no longer squeaky (not sure what version resolved the squeakiness) but it doesn't play at full quality.  When I feed it good quality 64kbps Opus, it plays it as if it's got a much lower frequency response.  I noticed that even though I'm sending it 64Kbps, it's sending me maybe 18 or 19Kbps... presumably sending voice-only quality.  I'll guess there's an SDP attribute to request different quality (?) but it doesn't make sense that it would down-sample what I provide.  I'll attach a 256Kbps mp3 of Chrome/beep/Firefox so you can hear the fidelity difference.

Comment 9

[mpietras]

Attachment: chrome-firefox.mp3

same Opus stream fed to Chrome then to Firefox, as recorded directly from the output sound card.

Comment 10

[Maire Reavy [:mreavy]]

How was the stream fed in?  We're downsampling Opus in WebRTC to 16KHz (8KHz bandwidth), so likely that's the cause of difference in audio quality.  If so, this bug should be closed - in any case, the original item is apparently resolved.  mpietras, please open a new bug on quality if it's not covered by the bug below.

We have an open bug with a patch to update to 32KHz - Bug 953265