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Clipping on certain tracks

  • 24 September 2021
  • 10 replies
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Userlevel 1

I have noticed that certain tracks are clipping on Deezer HiFi. I have emailed Deezer about this before and they first gave me the standard copy-paste responses and then refused to acknowledge the issue.

I reckon that the issue isn’t necessarily Deezer, but could also be caused by labels or artists not properly mastering their tracks.

I have Downloaded some problematic tracks directly from Deezer to demonstrate the issue, so there’s absolutely no chance that the Deezer application or my device is at fault here.

Some tracks where the clipping is obvious:

I hypothesize that Deezer is carelessly converting tracks supplied in formats with floating point samples to formats with fixed point samples, without properly limiting or attenuating them. What contradicts this hypothesis though, is the fact that the clipping doesn’t always occur at the 0dB point, but sometimes a bit under it. This would lead me to believe that it’s the mastering engineer’s fault.

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Best answer by Zipdox 4 October 2021, 13:23

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Userlevel 7
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Hi @Zipdox I have reported this to our music team.
Can you please confirm how often does this happens? Do you have more examples?
Thanks :)

Userlevel 1

Hi @Zipdox I have reported this to our music team.
Can you please confirm how often does this happens? Do you have more examples?
Thanks :)

Well it’s a song-specific issue. If I’d have to guess the issue is more common in electronically produced music, like EDM, but that isn’t to say it doesn’t occur in other genres. I might write a program to detect clipping in tracks in a way that can be automated.

Userlevel 7
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We really appreciate your help :nerd:

 

Userlevel 2
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I've noticed this too, but thought it might be due to Bluetooth or something. The above result can indeed be because of several conversions without care for settings. 

Userlevel 1

Oh so I had my suspicions about Tell Me Bout It, because the YouTube versions also kinda sounds like it’s clipping, and the peaks don’t look perfectly flat either. Anyway, I wrote a program to detect clipping. And using this I was able to determine that the Caramella Girls tracks were in fact clipping quite badly. Holiday was by far the worst, getting a score of a whopping 16 compared to 10 for Tokyo, which is also quite bad.

https://gitlab.com/zipdox/clipdetect

If you could send this to programmers at Deezer who know C, they can probably automate it to scan large numbers of tracks.

Userlevel 1

I reworked the algorithm to give a per mille score of clipping samples. Now a reasonable score would be under 2‰. Holiday is 8.8‰ and Tokyo is 5.2‰.

Userlevel 2
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Hi! Is there any work done on this? Even quiet songs from  Katie Melua have clipping and distorted sounds in the base tones.

 

This is not HiFi

 

 

Edit: Enabling Normalise Audio in the settings helps a little, only because on this track it atenuates the volume. 

Userlevel 1

I checked the track with both my algorithm and manually and it doesn’t seem to be clipping.

Userlevel 2
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I wonder then if its the Android App that did it? It sounds awful. 

Userlevel 7
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@Zipdox I have passed the feedback and mentioned the program you developed to our music team (I can’t guaranteed if they will be using it though)
Thanks for sharing :nerd:

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