Clipping audio in 2.6.2

iOS, iPad, iPhone, tvOS specific usage questions
timrosenberg
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Clipping audio in 2.6.2

Postby timrosenberg » 29 Jul 2015 17:29

I primarily use VLC for lossless audio. In the current version, the audio is clipping very mildly. It's easy to hear in the high frequencies with good headphones.

I have A/B tested with the same headphones, same iPhone volume, same tracks at the same time stamps, in different apps, and it's clearly a VLC problem.

fkuehne
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Re: Clipping audio in 2.6.2

Postby fkuehne » 30 Jul 2015 15:55

Can you share a sample file with us on http://streams.videolan.org/upload/ ?

Thanks a lot!
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Felix Paul Kühne
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timrosenberg
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Re: Clipping audio in 2.6.2

Postby timrosenberg » 30 Jul 2015 18:12

Well, it's weird; but, I'm not getting clipping today like I was yesterday. I'm using the same source, headphones, files, etc. I was hearing some high-frequency distortion tracking rhythmically with the bass frequencies. Made me think the low frequencies were pushing something too hard on the iPhone. But, today, it's not there.

I guess it could have been a bit of dirt or something on my headphones plug or in the headphones jack. The weird thing is it was only VLC that was doing it. Other apps, with the same files, had no problems. And it was repeatable yesterday.

Anyway, I'll UL the tracks I was using and let you see if you can hear it.

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Re: Clipping audio in 2.6.2

Postby johnmeyer » 30 Jul 2015 19:11

I am getting MASSIVE clipping in 2.6.2 and am in the process of rolling back. I've shared a small file which illustrates the problem. The video is 60p AVCHD from a Sony HDR-CX700 camcorder. The audio is AC-3 5.1, 448 kbps, 48kHz, 16 bit.

I just removed 2.6.2 and reinstalled 1.11.1, and the video plays perfectly.

I am running Windows XP Pro, SP3, 32-bit.

timrosenberg
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Re: Clipping audio in 2.6.2

Postby timrosenberg » 30 Jul 2015 20:09

Just for clarification, my clipping was heard on iOS 8.4. The files are ALAC ripped from my own CDs using iTunes. I haven't verified; but, I'm pretty confident there are no encoding errors. I use AKG K550 headphones.

@johnmeyer: Did you happen to check any other media besides a video?

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Re: Clipping audio in 2.6.2

Postby fkuehne » 31 Jul 2015 13:21

Hmm, I considered getting the same headphones, might be a reason to do it.

@johnmeyer: you have a totally different problem. VLC for iOS doesn't even decode AC-3 in the first place. Please do a separate post on the Windows forum. Thanks.
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Re: Clipping audio in 2.6.2

Postby timrosenberg » 31 Jul 2015 16:22

Well, don't get them just because of me. But, I don't think you will regret the decision, either. :)

fkuehne
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Re: Clipping audio in 2.6.2

Postby fkuehne » 31 Jul 2015 16:52

haha, no, I was looking for new ones anyway :)

btw. can you reproduce the clipping with VLC on the Mac with a similar loudness level?
VideoLAN
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Blog: https://www.feepk.net

timrosenberg
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Re: Clipping audio in 2.6.2

Postby timrosenberg » 01 Aug 2015 19:26

I'm getting clipping though my mBox and through the regular output of the iMac. It's a little worse through the built-in output.

I also tested on Shure SE535 IEMs. I hear the same thing, only less so. Probably more due to the Shure's sound signature than anything else.

I also have a different problem: VLC cuts off the first second or so of the track.

Gear: VCL 2.2.1 (clean install), iMac (27-inch, Late 2012), OSX 10.10.4, mBox Mini 2, AKG K550 headphones, Shure SE535 IEMs.

I haven't tested different speakers yet; but, I can't really trust mine. They run audio from my iMac through a wireless system. If you really want it, I can run some cables.

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Re: Clipping audio in 2.6.2

Postby Poldy » 08 Oct 2015 20:59

I opened a ticked (#15619) and moved the sample to: http://streams.videolan.org/issues/15619/

This information is going to help our developers - for everybody else it's going to be useless ;)


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