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Topic: scratchwave is changing amplitude

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Grok32Home userMember since 2019
The scratchwave is changing amplitude levels while zooming. It varies by song but I can't relate it to any specific file types. Some songs vary only a bit and some vary quite a bit. In worst cases maybe 400%. I have verified the same result on the default skins as well as the multi-touchscreen skin. The biggest jump is about 30-40% from full zoom.


http://larrybrinson.com/Pictures/vdj3.jpg

 

Posted Wed 15 Jan 20 @ 1:23 am
The scratchwave does not change amplitude by zooming. However it does change amplitude when you change gain slider position.
Are you sure you haven't modified gain setting between these screenshots ?
 

Posted Wed 15 Jan 20 @ 7:45 am
Grok32Home userMember since 2019
Absolutely. The only change in the attached image is one click of the mouse wheel on the scratchwave. It does not do it on every song and the effect varies by song. The example here is one of the worst cases I could find. Also it is worst at this particular click point. It does change amplitude at greater zoom levels but only by a small amount. The result is an apparent flicker in the display.

https://www.youtube.com/watch?v=dlKvtJryB1o
 

Posted Wed 15 Jan 20 @ 12:28 pm
AdionPRO InfinityCTOMember since 2006
You do realize your gain (and eq's) are maxed out?
Does it also happen when gain is at 12 o'clock ?
 

Posted Wed 15 Jan 20 @ 1:45 pm
Grok32Home userMember since 2019
Yes, its just easier to see with the gain up. This song has low audio which led me to notice the issue. I thought at first that the low audio was the culprit but that is not the case. It happens on some songs with normal audio levels.

https://www.youtube.com/watch?v=EpG6jbqyssE
 

Posted Wed 15 Jan 20 @ 2:13 pm
Grok32Home userMember since 2019
 

Posted Wed 15 Jan 20 @ 2:42 pm
Grok32Home userMember since 2019
 

Posted Mon 17 Feb 20 @ 1:51 pm
Grok32Home userMember since 2019
 

Posted Tue 18 Feb 20 @ 4:32 pm
Grok32 wrote :
Any feedback on this? Can anyone else replicate this?

It occurred to me after reading this post ( https://www.virtualdj.com/forums/233315/General_Discussion/Autogain.html) that this may explain why autogain sometimes doesn't work properly.

I have never seen something like that before.
I'm using VDJ since 2007, and the only problem I had with only one MP3 was that the grid disappeared while the track was playing.
Can't explain how this would happen, but it definitely was an error in the MP3's coding.
I imported the track into a DAW and exported it without any changes, and the problem was gone.
Simply by rendering a new MP3. But what you have descriped there I really never have seen before...
Maybe you try the upper solution to see what happens?

P.s.:
It is absolutely logical that the Waveform changes amplitude, but I find it kinda annoying because I would like to also see a normal waveform even in difficult mixing-inviroment where I have to play a lot with the gains. Is there a way to turn the changing of the amplitude off?
 

Posted Wed 19 Feb 20 @ 4:25 am
Grok32Home userMember since 2019
I don't believe the amplitude is actually changing as the volume doesn't change. It is just the scratch wave display. I have tried converting flac files to mp3s and it makes no difference. The songs that do it behave the same way no matter how they are encoded. One thing I have found was that when a particular song does it, all songs on the same cd do it.
 

Posted Wed 19 Feb 20 @ 5:19 am
Grok32 wrote :
I don't believe the amplitude is actually changing as the volume doesn't change. It is just the scratch wave display. I have tried converting flac files to mp3s and it makes no difference. The songs that do it behave the same way no matter how they are encoded. One thing I have found was that when a particular song does it, all songs on the same cd do it.

No no, I understand that in your case it has nothing to do with the gain.
I wrote the "p.s." because some of the developers are in this post, too. :)

So the waveform regularly changes its appearance while zooming in order to show the amplitudes correctly.
If you zoom (a song which doesn't have this problem) you will see that the peaks are slightly changing because there are moving peaks with a higher amplitude into the displayed section. So in order to show the relations to each other they change a little bit... (At least this is what I discovered)
This seems to be desired and it is also a right behavior if you want to show the maximum amplitude of a particular section.

But thinking of that, maybe there is something in the mastering of the particular CD, which causes a threshold inside VDJ to behave like this.
The software has to convert sound (icluding all frequencies, its energy and loudness) into some picture.
So maybe some messed up low-end frequencies in the mastering could cause a behavior like this.
#JustAnIdea
 

Posted Wed 19 Feb 20 @ 9:58 am
AdionPRO InfinityCTOMember since 2006
Do you have some track titles for songs for which this happens?
 

Posted Wed 19 Feb 20 @ 10:10 am
Grok32Home userMember since 2019
Any song from Dwight Yoakam's 'Guitars Cadillacs Etc. Etc' 'Bury Me' is a good example.

I don't believe it is in the mastering. Unless it is something sub-audible. I have tried re-recording and re-encoding the same song with various software all with the same result.

I have also checked downloaded versus ripped from the original CD with the same results.
 

Posted Wed 19 Feb 20 @ 12:29 pm
Grok32Home userMember since 2019
 

Posted Wed 19 Feb 20 @ 12:54 pm
Have you tried a different PC ?
It seems like a graphics card wrong settings issue to me
 

Posted Wed 19 Feb 20 @ 4:11 pm
locodogPRO InfinityModeratorMember since 2013
 

Posted Wed 19 Feb 20 @ 4:44 pm
Grok32Home userMember since 2019
I tried my laptop and it is the same (and it is still on the 2018 version). The examples are from my desktop (2020). It only does it on the scratchwave. To see it, it helps to set the gain higher but it is still there even with the gain set very low. Vertical or horizontal makes no difference. I don't have the mix locodog posted but I tried the original version and it indeed does have the issue.

https://www.youtube.com/watch?v=hfULtvbOD4M

 

Posted Wed 19 Feb 20 @ 5:56 pm
Grok32Home userMember since 2019
I checked a little further on the above song. I have 7 different versions. 5 have the issue 2 do not. Both of the songs that do not have the issue, came from compilation CDs. None of the songs on either CD that these songs were ripped from had the issue.
 

Posted Wed 19 Feb 20 @ 6:15 pm
Grok32Home userMember since 2019
I also attempted to see if this affects autogain. The top song doesn't have the issue and autogain sets the gain around 49%. The fifth song (with the issue) autogain sets the gain around 75% - 80%.

https://www.youtube.com/watch?v=EM18xMCk2Bk
 

Posted Wed 19 Feb 20 @ 6:39 pm


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