Volume fluctuation in VLC for iOS

[RoyalScam]

When I connect to my local server and play FLAC files, I'm hearing an occasional "pumping" volume. It'll lower and raise back. It sounds like there's some sort of dynamic limiting or compression being applied, but I can't find a setting for that. Can someone help me out?

There's also a very occasional issue where the speed seems to fluctuate like a vinyl record's pitch control being tampered with, but the volume is the bigger "deal breaker" for me.

[RoyalScam]

19 views...0 responses. Bueller? Bueller???

[fkuehne]

We don't really process audio that way regarding volume. The desktop version of VLC includes a normalizer, which was never ported to iOS though. Regarding the speeding, that might be occur if the device is under heavy load. Does the volume problem always happen with the same files? Is it reproducible?

[RoyalScam]

Put it this way, there's a definite drop in sound quality that I perceive vs playing the same file in other audio players on iOS (like Flacbox or Foobar).

I'll try to find some files that absolutely exhibit audible differences and post them.

[fkuehne]

Great, thanks a lot! If you want to do so privately, feel free to email me at my twitter handle at videolan.org.

[jshep231]

I am seeing this behavior on VLC 224 for Win 10 also.

Whenever I have VLC in the foreground, it sounds louder and as if some spatialization/expander filter is enabled. When I click on another window to change focus, it gets quieter/normal. The same 192kbps VBR ogg audio stream sounds normal in my firefox browser and others.

[Domminney]

I have had the same thing. Latest iOS on a 6S plus, and I reinstalled VLC.

I get audio limiting / compression on all audio files I play but I don't get the same using apple's music app.

[Jap33]

This volume issue is still prevalent. It is recognizable when I'm playing mp3 audio files...I'm running VLC on iPhone 6 IOS 10.3. Developers kindly look at this and fix on the next update please...

[Oubadah]

I've been wanting to post about this issue for months, but the forum wouldn't let me sign up for some reason so I gave up. Tried today, and finally able to register.

I can't believe there isn't more discussion about this issue. Unless I'm missing something, iOS VLC's audio is severely messed up. How are people not noticing this?

Now, I've been through the VLC menus several times with a fine tooth comb, and I can find no setting that looks like it would cause this. Also, this is iOS we're talking about, so not many variables in terms of system configuration.

VLC is using some kind of aggressive normalization and it sounds awful. Here is audio I captured from my iPhone's analogue jack, Foobar2000 followed by VLC:



Yes, that's the same piece of music! (and yes the song is a product of the Loudness Wars, but ignore that. You can clearly see what VLC is doing. #2 is not normal. It's supposed to be a quiet intro, then loud, but played in VLC it sound like someone turns the volume down the moment the loud part begins)

Come on guys, this software is unusable. Or maybe I'm an idiot and missing something obvious. Please let me know.

PS. The track featured above is My Sacrifice by Creed (yeah, direct your hate-mail to my inbox if you must ). The intro is a perfect showcase for the issue.

[RoyalScam]

BLESS YOU OUBADAH!!! That is EXACTLY what I’ve been experiencing and posting about since last year in this thread. Multiple app updates have occurred and not ONE addresses this issue. It’s accompanied by a pumping sound, too, like a compressor gone awry.

I haven’t used the app regularly in months because of this glitch.

PLEASE FIX THIS!!!

[Oubadah]

Every couple of months I install VLC on my iOS device to see if this issue has finally been addressed, and every time I am disappointed. How many years is it going to take? How is there no one else complaining about this? I guess iOS users aren't as discerning as they like to think.

VLC for Android does not do this BTW.

[RoyalScam]

I'd imagine it's because you and I are the only two people in the world attempting to use VLC for audio-only (no video) on iOS. Because, discerning or not, you'd have to be DEAF not to hear the issue.

[unidan]

Hi, I don't own an iPhone and tried to understand the issue but I can't really find out. In the logs, it loads scaletempo, float_mixer and equalizer but they are all on default values doing nothing. I'll try to reproduce when possible.

Which iPhone and which version?

[Oubadah]

Hi, I don't own an iPhone and tried to understand the issue but I can't really find out. In the logs, it loads scaletempo, float_mixer and equalizer but they are all on default values doing nothing. I'll try to reproduce when possible.

Which iPhone and which version?

I have reproduced the issue on all of my iOS devices: iPhone SE, iPad 2017 and iPad Air 2.

Please let me know if there’s anything else I can do to help.

[RoyalScam]

Happened on my old iPhone 6, continues on my recent iPhone XR and iPad mini 2

And, incidentally, it's more of an audio COMPRESSION issue than volume fluctuation, per se. Look at the waveforms posted a few posts above to "see" the issue we're hearing. There appears to be an audio compression algorithm getting activated somehow.

[unidan]

Hi, we'll provide a fix, we will warn you when it's included in a release.

[Henning]

Hi, the problem is still present (iPhone XS, VLC 3.2.0 (334)). do you think there will be a fix anytime soon?

[RoyalScam]

I was hoping the new update would fix this. I guess they simply don’t care, or don’t have the capacity to fix it. Shame.

Meanwhile I’ve moved onto Flacbox. Not perfect, but no volume fluctuations or compression issues.

[Sl@zE]

Guys, check your app version! Have a look please:
https://code.videolan.org/videolan/vlc-ios/issues/706

[unidan]

Hi. Actually it has been merged for a while but I couldn't find this subject back. Thank you for pointing this out !
Compressor was indeed always activated.

[RoyalScam]

Hi. Actually it has been merged for a while but I couldn't find this subject back. Thank you for pointing this out !
Compressor was indeed always activated.

So, unidan, does that mean you fixed the issue and the current version in the App Store has the compressor de-activated by default?

[unidan]

I didn't, but the iOS team did, and it's off by default on 3.2.0 and some previous versions: https://code.videolan.org/videolan/vlc-ios/issues/148

[Sl@zE]

Generally issue still not fixed. Have a look-
https://code.videolan.org/videolan/vlc-ios/issues/706

[RoyalScam]

Not surprised

[tguillem]

Hello,

VLC developer here,

I see only two components that could change the audio in VLC

- The Equalizer: by mistake,it was always enabled in the past iOS versions. This had been fixed (it is now disabled by default).

- The clock that is doing A/V synchronization (yes it also happens if you don't have video). The audio can be resampled in order to catch up with a delay.
It is only fixed in VLC 4.0. In this future version, audio will never be tempered to catch up with a delay again.

In the meantime (since VLC for IOS is still using VLC 3.0), I did my best to minimize this re-sampling on iOS.
In the last iOS version, from my tests, the audio track is starting without triggering the resampler, but this could depend on the iOS device, audio headphone/soundcard, or sample.

If you still have this issue now, could you share with me:
- Your device
- Your audio configuration: speaker/headphone/bluetooth (which device?)
- Your audio/video sample.