Bug 1783 – Preview fails when selection extends before zero

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••• Keywords •••

Audacity 3.0.3 development began 19th April 2021

Audacity Bugzilla

Bug 1783 - Preview fails when selection extends before zero


Summary:	Preview fails when selection extends before zero

Status:	RESOLVED FIXED

Product:	Audacity
Classification:	Unclassified
Component:	Audio IO
Version:	unspecified
Hardware:	Per OS All

Importance:	P2 RepeatableAll
Assigned To:	Default Assignee for New Bugs

URL:	https://sourceforge.net/p/audacity/ma...
Keywords:

Depends on:
Blocks:
	Show dependency tree / graph

Reported:	2017-11-14 13:30 UTC by Steve Daulton
Modified:	2018-08-20 11:45 UTC (History)
CC List:	6 users (show)

See Also:
Steps To Reproduce:	1) Generate some audio 2) Time shift so that it starts before zero (note that tracks always start before zero when overdubbing) 3) Select all 4) Preview any non-RTP effect (for example, Amplify). Big scary bug message!
Release Note:
First Git SHA:
Group:	---
Workaround:
Closed:	2018-08-20 00:00:00

Flags:	stevethefiddle: Regression+ petersampsonaudacity: Test‑OK‑Win+ petersampsonaudacity: Test‑OK‑Mac+ stevethefiddle: Test‑OK‑Lin+

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Description Steve Daulton 2017-11-14 13:30:48 UTC

The error message is due to the THROW_INCONSISTENCY_EXCEPTION in
WaveTrack::InsertSilence()
but we can't just return from there, because we still need to set the
clip offset.

I would have rated this as P3 because of the impact on users when working with multi-track projects, but elevated to P2 as it is a regression.

Note that preview is not correct in Audacity 2.1.2 either (preview playback starts late when selection extends before zero), but in the most common case where the track extends only a fraction of a second before zero, users will be unaware that there's anything wrong.

Comment 1 Peter Sampson 2017-11-15 04:45:39 UTC

Curiously it is only the Preview that is affected. the user can proceed to use the OK button to work the effect. 

And testing with Amplify readily shows that using Select All with some audio before zero the amplify is indeed applied to all the audio including the pre-zero audio.

Comment 2 Paul L 2017-11-19 10:34:55 UTC

Fixed at https://github.com/audacity/audacity/commit/2f40c1c77ef59258f4cf6450aceaf728cb46fe45

Comment 3 Peter Sampson 2017-11-20 07:35:06 UTC

(In reply to Paul L from comment #2)
Testing on Macbook Pro macOS High Sierra 10.13.1 with  audacity-macos-nightly-2.2.1-c1779c8.dmg 

Test OK - no internal error/assert message - Preview plays ok with audio before T=0

And the Apmlify works with the OK also amplifying the before zero audio that is selected (but hidden)

Cannot test on Windows yet - as we still have no nightly builds

Comment 4 Peter Sampson 2017-11-24 11:29:49 UTC

Testing on W10-CE with 2.2.1 RC1


Test OK - no internal error/assert message - Preview plays ok with audio before T=0

And the Apmlify works with the OK also amplifying the before zero audio that is selected (but hidden)