Many vertical lines on the spectrogram (there should be none)
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#283 Many vertical lines on the spectrogram (there should be none)
First, thanks for making this software and supporting it.
I have been searching for something good and thought I found it with Sonic Visualiser. It is made to work with multiple inputs! But unfortunately the bug I am about to describe, disqualifies it.
The problem is illustrated in the attached screenshot
Unfortunately there are many vertical lines that make it impossible to detect "real" vertical lines, which are produced when a pure tone is interrupted very briefly. I am analyzing a communication system which has this intermittent problem. A good spectrogram is an excellent way to spot that in the present and in the distant past. For some reason, Sonic Visualiser is drawing a vertical line every time it draws a new block of information.
Expected behaviour: No drawing artifacts. In the case of a pure tone, there should be one horizontal line (at a specific frequency) and nothing else.
Hopefully that gets corrected. Once it does I will also report the problem with the scrolling. Currently it does not show a nice smooth scrolling spectrogram. Instead, it jerks around as it draws some block of information. then shifts everything by that block width, and repeats this all the time. As an example of smooth scrolling, there is Techmind Spectram Analysis (freeware).
Related
Hi Jean - this is alarming, thank you for reporting it. Which version of Sonic Visualiser is this?
For completeness, could I ask you to attach an audio file with which it exhibits this problem?
Thanks for looking into this problem. The version is here:
[cid:e638fd83-7b57-4357-a65b-f4909d577657]
I have attached a sample tone of 250 Hz. However, note that the problem occurs regardless of the source audio (voice, music, tones, noise). The louder, the better, to see the problem.
This file is being played into an audio device A (source) and transmitted to another audio device B. I am trying to use Sonic Visualizer to show the output of B in real time. The "record device" is set here:
[cid:aebc81db-993e-428c-854c-4df11da6c4f4]
It does plot a spectrogram, but with a major problem: it draws vertical lines, and jerks around.
[cid:3033db4d-b2a0-46ff-91ab-44b7c0498ceb]
Regards,
Jean Goulet
From: Chris Cannam cannam@users.sourceforge.net
Sent: Saturday, June 13, 2020 2:43 AM
To: [sv1:bugs] 283@bugs.sv1.p.re.sourceforge.net
Subject: [sv1:bugs] #283 Many vertical lines on the spectrogram (there should be none)
Hi Jean - this is alarming, thank you for reporting it. Which version of Sonic Visualiser is this?
For completeness, could I ask you to attach an audio file with which it exhibits this problem?
[bugs:#283]https://urldefense.proofpoint.com/v2/url?u=https-3A__sourceforge.net_p_sv1_bugs_283_&d=DwMCAg&c=DSwo5WHAmQUR7kvQRzLeTQ&r=y06u2IIjtqNhug51TFMOJo6rkC6SN1lD5fxNPjOosVI&m=1pFhX3FOpdEjBtic0o61G6m2AUUQ_HFvx3a0DpdmIo0&s=9L7fBsYC8PCF-X1G3xq7TSbJ-t1nnVO15K4rzO_6xBg&e= Many vertical lines on the spectrogram (there should be none)
Status: open
Group: v3.0
Created: Sat Jun 13, 2020 01:08 AM UTC by Jean Goulet
Last Updated: Sat Jun 13, 2020 01:08 AM UTC
Owner: nobody
Attachments:
First, thanks for making this software and supporting it.
I have been searching for something good and thought I found it with Sonic Visualiser. It is made to work with multiple inputs! But unfortunately the bug I am about to describe, disqualifies it.
The problem is illustrated in the attached screenshot
Unfortunately there are many vertical lines that make it impossible to detect "real" vertical lines, which are produced when a pure tone is interrupted very briefly. I am analyzing a communication system which has this intermittent problem. A good spectrogram is an excellent way to spot that in the present and in the distant past. For some reason, Sonic Visualiser is drawing a vertical line every time it draws a new block of information.
Expected behaviour: No drawing artifacts. In the case of a pure tone, there should be one horizontal line (at a specific frequency) and nothing else.
Hopefully that gets corrected. Once it does I will also report the problem with the scrolling. Currently it does not show a nice smooth scrolling spectrogram. Instead, it jerks around as it draws some block of information. then shifts everything by that block width, and repeats this all the time. As an example of smooth scrolling, there is Techmind Spectram Analysis (freeware).
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Related
Bugs: #283
Thanks for the extra information!
If I understand correctly, you are always recording the signal into Sonic Visualiser and displaying a spectrogram "live" as it records? Presumably if you load the original audio file directly into SV its spectrogram comes up clean?
What is the audio recorded by SV like? (You can find the recorded audio files under File -> Browse Recorded And Converted Audio) - is that a clean signal or is the noise shown in the spectrogram actually present there as well?
I'm trying to be certain whether this is a problem in the block-by-block updates (e.g. it isn't properly handling the partial final frame when the audio file is updated) or whether the display is accurate but there is noise in the recording itself (e.g. caused by a clock sync problem due to using two unsynchronised audio devices simultaneously, one for record and a different one for playback).
Thanks!
Hi again - I've just put out v4.1 of Sonic Visualiser - I had hoped to take a look at this bug in time for that, but in the end I decided it wasn't practical as the release has been delayed a few times already and we really wanted to get it out of the door. It might be worth re-testing your situation using the new release, though I'm fairly sure there's nothing in it that should make a difference here.
In the meantime, if you are able to answer the questions from my previous comment, that would be really helpful. Thank you!
My responses are preceded with [JG] below.
Thanks,
Jean Goulet
From: Chris Cannam cannam@users.sourceforge.net
Sent: Tuesday, June 16, 2020 4:48 AM
To: [sv1:bugs] 283@bugs.sv1.p.re.sourceforge.net
Subject: [sv1:bugs] Re: #283 Many vertical lines on the spectrogram (there should be none)
Thanks for the extra information!
If I understand correctly, you are always recording the signal into Sonic Visualiser and displaying a spectrogram "live" as it records?
[JG] Yes, live.
Presumably if you load the original audio file directly into SV its spectrogram comes up clean?
[JG] Yes, clean.
What is the audio recorded by SV like? (You can find the recorded audio files under File -> Browse Recorded And Converted Audio) - is that a clean signal or is the noise shown in the spectrogram actually present there as well?
[JG] Clean.
I'm trying to be certain whether this is a problem in the block-by-block updates (e.g. it isn't properly handling the partial final frame when the audio file is updated) or whether the display is accurate but there is noise in the recording itself (e.g. caused by a clock sync problem due to using two unsynchronised audio devices simultaneously, one for record and a different one for playback).
[JG] Certainly appears to be a messed up display. Unfortunately for me, I am relying entirely on the real-time display, hence it's a showstopper for me. Hoping to eventually see an accurate display once the problem is fixed (with a fast response and smooth movement of the spectrogram).
Thanks!
[bugs:#283]https://urldefense.proofpoint.com/v2/url?u=https-3A__sourceforge.net_p_sv1_bugs_283_&d=DwMCAg&c=DSwo5WHAmQUR7kvQRzLeTQ&r=y06u2IIjtqNhug51TFMOJo6rkC6SN1lD5fxNPjOosVI&m=3rLlTsRgd6uoybAUl0Nd4JB9UK_V2Vs_lBiQN_V-UYo&s=jEms3TvRnIlSV0y1DhqiNcngWWd7McLMrW6fdVaFTZ0&e= Many vertical lines on the spectrogram (there should be none)
Status: open
Group: v3.0
Created: Sat Jun 13, 2020 01:08 AM UTC by Jean Goulet
Last Updated: Sat Jun 13, 2020 06:43 AM UTC
Owner: nobody
Attachments:
First, thanks for making this software and supporting it.
I have been searching for something good and thought I found it with Sonic Visualiser. It is made to work with multiple inputs! But unfortunately the bug I am about to describe, disqualifies it.
The problem is illustrated in the attached screenshot
Unfortunately there are many vertical lines that make it impossible to detect "real" vertical lines, which are produced when a pure tone is interrupted very briefly. I am analyzing a communication system which has this intermittent problem. A good spectrogram is an excellent way to spot that in the present and in the distant past. For some reason, Sonic Visualiser is drawing a vertical line every time it draws a new block of information.
Expected behaviour: No drawing artifacts. In the case of a pure tone, there should be one horizontal line (at a specific frequency) and nothing else.
Hopefully that gets corrected. Once it does I will also report the problem with the scrolling. Currently it does not show a nice smooth scrolling spectrogram. Instead, it jerks around as it draws some block of information. then shifts everything by that block width, and repeats this all the time. As an example of smooth scrolling, there is Techmind Spectram Analysis (freeware).
Sent from sourceforge.net because you indicated interest in https://sourceforge.net/p/sv1/bugs/283/https://urldefense.proofpoint.com/v2/url?u=https-3A__sourceforge.net_p_sv1_bugs_283_&d=DwMCAg&c=DSwo5WHAmQUR7kvQRzLeTQ&r=y06u2IIjtqNhug51TFMOJo6rkC6SN1lD5fxNPjOosVI&m=3rLlTsRgd6uoybAUl0Nd4JB9UK_V2Vs_lBiQN_V-UYo&s=jEms3TvRnIlSV0y1DhqiNcngWWd7McLMrW6fdVaFTZ0&e=
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Related
Bugs: #283