Withdraw stored analysis if the track sample count changes

[mixxxbot]

Reported by: daschuer
Date: 2015-05-22T06:02:53Z
Status: Confirmed
Importance: Medium
Launchpad Issue: lp1457746
Tags: easy, waveform

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This may happen if the track was cut or in case of seek decoding issues (still in 1.12 alpha).
Currently the waveform does not fit to the samples and the sync feature will fail is such a case.

[mixxxbot]

Commented by: joseph-chilcott
Date: 2015-07-08T22:07:38Z

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Hi, I am new to the Mixxx project and as thought I would try and tackle this as my first bug. Would I be able to get more information on this bug and how to replicate it? When you refer to stored analysis, is this the pre-view wave form that appears after dragging a track onto one of the decks?

Thanks,
Joe

[mixxxbot]

Commented by: daschuer
Date: 2015-07-09T06:05:47Z

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Thank you for offering you help.

Reproduce:

• play a track in Mixxx
• close Mixxx
• cut some samples from the beginning of the track (using e.g. Audacity)
• Play this track again

What happens:
Beatgrid and waveform have an offset, (still match the old track)

What should happen:
Mixxx should detect this and reanalyze the track.

I think the same will happen if you replace the track with a completely different one.

Todo:

• setup a powerful development environment.
• Analyse why it happens.
• I think we have already some code to detect some of these situation in Library scanner. Check how this can interact with this issue.
• Propose a solution.
• Code it.

This will help to start:
http://www.mixxx.org/wiki/doku.php/bugfix_workflow

And ... Ask, if you get stucked.

[mixxxbot]

Commented by: joseph-chilcott
Date: 2015-07-10T20:59:41Z

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Hi Daniel,

Many thanks for the information. Just one thing, when you say 'close Mixxx' do you mean minimise mixxx or exit mixxx? The reason I ask is, mixxx does not seem to retain a previous session once closed. If I do close mixxx and then reload the edited track, the waveform is updated and represents the edited version of the track. Sorry if this is a newbie question :)

[mixxxbot]

Commented by: daschuer
Date: 2015-07-11T11:18:49Z

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I mean: Exit Mixxx.

I have just tested this:
I have started Mixxx, played Two tracks, closed Mixxx, switched the names from the tracks.
After restart. The first track contains the audio from the second track and vice verse. The waveform is not reanalysed.

[mixxxbot]

Commented by: ferranpujolcamins
Date: 2015-07-30T18:06:40Z

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Would this work?

1-Store in the database the last time when Mixxx modified a track file.
2-When the track is loaded, compare the database last modified time with the OS last modified time. If Mixxx is not the last app to modify the track, re-analyze it.

[mixxxbot]

Commented by: joseph-chilcott
Date: 2015-08-02T23:44:52Z

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Hi Ferran,

Have you been able to replicate this issue, I am still having problems.
When I restart Mixxx, it never remembers what I have cued up on either
deck. Therefore I do not see this problem as I am forced to reload the
track each time. This could be a newbie thing (I have looked through the
mixxx documentation and config but could not see anything that would help.

If you were able to to replicate this issue can you tell me what the Git
commit ID was that you are building against when you see this issue? (
Daniel- can you tell me the Git commit ID that you are also building
against when you see this issue?)
I cannot comment in much depth on the solution you have proposed, however
it seems reasonable. Would this solution work if the user loaded a track
in mixxx, minimized Mixxx, edited the track and then maximized Mixxx again?

Many thanks,
Joe

On Thu, Jul 30, 2015 at 7:06 PM, Ferran Pujol <email address hidden>
wrote:

Would this work?

1-Store in the database the last time when Mixxx modified a track file.
2-When the track is loaded, compare the database last modified time with
the OS last modified time. If Mixxx is not the last app to modify the
track, re-analyze it.

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report.
https://bugs.launchpad.net/bugs/1457746

Title:
Withdraw stored analysis if the track sample count changes

Status in Mixxx:
New

Bug description:
This may happen if the track was cut or in case of seek decoding issues
(still in 1.12 alpha).
Currently the waveform does not fit to the samples and the sync feature
will fail is such a case.

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https://bugs.launchpad.net/mixxx/+bug/1457746/+subscriptions