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IDProjectCategoryView StatusLast Update
0008029ardourbugspublic2020-05-27 22:12
ReporterMisterBenjamin Assigned To 
PrioritynormalSeverityminorReproducibilityalways
Status closedResolutionfixed 
PlatformSome Other LinuxOSSome Other LinuxOS Versionunknown
Product Version6.0-pre1 
Summary0008029: CD marker should not be restricted to at least two seconds after session start
DescriptionA few days ago, '0007942: Disallow placement of a CD marker at location zero' removed the possibility to place a CD marker at session start (zero). Before it was possible and one could export a valid cue with it, but after saving and reopening the session, the same policy was enforced by removing the CD flag from the marker.

After some research, it is my understanding that the cue sheet "should not or even must not" list the 2 seconds pregap for track 1 to fulfill the Redbook standard. It is added by means of the 'PREGAP' command (generated silence not part of the data file) by the software interpreting the cue sheet. Currently, when placing the first CD Marker two seconds (or more) after session start, an exported cue will contain an additional "index 0" pregap, which might contain audio (e.g. hidden track). This "potentially audible" pregap will be added to the two seconds of "generated pregap", so that with an Ardour exported cue you will always at least have a 4 seconds pregap, which is not desired. It might even lead to problems with some CD players.

My understanding is based on some experimentation and sources on the internet which are in german, so I will not link them here. Isn't there a proper standards document for CUE sheets?

Burning a couple of CDs with various versions of an exported cue, I learned that cdrdao and wodim (cdrecord) handle things a bit different. cdrdao seems to be more forgiving and also does what you would expect. wodim's cue handling is a bit awkward. wodim doesn't accept a cuefile which you exported from Ardour which has the two seconds Track 1 Index 0 pregap. It also complains that the session end marker wasn't snapped to CD frames. wodim creates audible pregaps (index 0) of two seconds from the previous track's ending, even if they are not listed in the cue sheet. cdrdao seems to do what the cue really tells him, plus generating and inserting the two seconds pregap for Track 1. Some sources claim, that to be really Redbook standard conform, you need to have at least two seconds (silent) pregap between the tracks, but in my experience all CD players (including my Technics from 1992) don't care.
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MisterBenjamin

2020-04-20 08:57

reporter   ~0023823

Long story short: By allowing CD markers to coincide with session start, an exported cue can be recorded with cdrdao and wodim and both will generate a two seconds pregap. By disallowing CD markers to coincide with session start, cdrdao will produce a CD with 4 seconds pregap and wodim will not accept the cue.

MisterBenjamin

2020-05-27 22:11

reporter   ~0024285

Fixed in 974ae5100f

Issue History

Date Modified Username Field Change
2020-04-20 08:47 MisterBenjamin New Issue
2020-04-20 08:57 MisterBenjamin Note Added: 0023823
2020-05-27 22:11 MisterBenjamin Note Added: 0024285
2020-05-27 22:12 MisterBenjamin Status new => closed
2020-05-27 22:12 MisterBenjamin Resolution open => fixed