Audio quality on Karaoke stream is poor

[potent bloom]

I was comparing the audio quality of the stream audio versus the mp3s, and it sounds like a LOT of high frequency detail is missing
it is far more than just what a standard 160kbps ffmpeg encode causes, so this seems quite strange to me

[late pendant]

This is probably due to twitch modifying the audio a bit for optimization

[ionic wadi]

Yea you cant blame anyone else expect twitch for that, if you want better quailty you can just wait till pb upload the karaoke tracks on google drive.

[potent bloom]

I'm still not sure..
I do know they warp it (slightly speed it up) sometimes.. but removing half of the high frequencies? That seems crazy to me
And you encode your audio encodes, only 160p and 360p are reencoded by Twitch

[late pendant]

It depends on your connection too and (due to server load) how many people are watching as well I think

[potent bloom]

and it affects the VOD too, I guess? cause that's what I saved
still, what I usually hear are just like... subtle pitch shifts

[heavy dagger]

@violet light what did you say about twitch audio again

[violet light]

It absolutely and utterly sucks

[late pendant]

yes it would

[potent bloom]

I still find it strange, Twitch only reencodes the 160p and 360p streams, right? I know if you want to upload 320kbps audio, there will be 320kbps audio, unless you select the 160p or 360p streams...
the artifacts I'm hearing sure seem like compression artifacts, and not warping due to OBS or Twitch speeding/slowing down the audio to meet certain timings...

[violet light]

The stream raw data has 173Kbps audio

[potent bloom]

Right, but it still shouldn't be nearly this bad
I tried encoding the mp3 with 160kbps ffmpeg, which is one of the worser encoders you can choose, and it is not affecting the higher frequencies like I'm hearing on the stream

Isn't it also right around 160? Lemme check..

hmm, I'm seeing slightly below 160kbps to brief spikes up to 168kbps

seeing more wild spikes during the talking parts, but still probably averaging somewhere between 160 to 165kbps

[violet light]

Twitch audio just sucks

[potent bloom]

I'm gonna be completely honest, I don't like to just buy "oh, it's just cause Twitch or YouTube" because a lot of times people say that, I can disprove it.. it's often just said cause it's the easy "pfft, it's just the platform"
so.. I'm still very maybe it is Twitch, but I have extreme doubts that this isn't something else on the user side that is messing with the audio

[violet light]

Let me just do a quick ffprobe

AAC

CFRB encoded with equivalent settings

Wait
I just realized Twitch also re-samples the audio

That kinda maybe does it

This should be as close to what is coming from Twitch as I can get

Spectrogram, AAC 164Kbps 48kHz vs original at 44.1kHz

It's pretty likely to be Twitch compression

[potent bloom]

so... I guess it's the 160kbps with Twitch that is the issue
pfft, and Twitch wants to cap to 160kbps for enhanced broadcasting (which I think Vedal doesn't use), so dumb
hmm, lemme pull up the two clips I posted in a spectrogram...

looks like about 9khz and onward it just gets absolutely butchered

the volume starts decreasing drastically...

[violet light]

And also the resample, that does a lot to ruin things

[potent bloom]

yeah, idk... from what I know, unless you using a really bad resampler, it shouldn't affect it too much...

[violet light]

Well, maybe it's the bitrate and the resample combined

[potent bloom]

I just listened to this.. it sounds N O T H I N G like Twitch is causing
I'm still very until I have more proof of what is happening
but Twitch is already doing some weird stuff by resampling.. hmm...
I just... hmm, I guess I could try streaming on Twitch and see what happens to the audio... would just need a few seconds

[violet light]

It's the closest I can get with ffmpeg
If you know a better tool you can try to mess with it

[languid estuary]

might be interesting to compare it with b2 streams, although I think b2 only offers low quality vods for unregistered users

[potent bloom]

something is.. seriously messed up
idk if it's user side or Twitch... but this is the mp3 reencoded to 96kbps ffmpeg and resampled to 48khz
and it STILL sounds better

[violet light]

Maybe it's Unity then?

I believe Unity is the first thing that plays the audio, which Vedal's OBS then captures, then that is sent to the different streams of Vedal's multistream

I think there could be up to 3 re-encodes

1. Unity plays the file
2. OBS captures it
3. the audio is converted by Twitch

Unity re-encoding the thing to lossy would be stupid though

[late pendant]

honestly I'm having doubts now it's just twitch since it's not always that bad tbh

[potent bloom]

it's also like.. the higher frequencies aren't super broken up, just very turned down.. it's... weird

[thorn vector]

You have unlocked new role

[violet light]

So strange
Who knows really

It could be any part of the chain, or an interaction of multiple parts
Unity, with how horribly bad it is, seems like a big suspect

[languid estuary]

yup
we already know he has some audio issues with tts stuttering, there could be more surprises hidden somewhere on his side

[violet light]

Either way, the stream quality absolutely does suck, I can hear noticeable distortion in it when listening

[potent bloom]

heh, yeah, but I think Evil's stutters are cute

[languid estuary]

cute or not, it's a sign of something
hope things get fixed eventually
good quality was a big part of his success in my opinion