View Issue Details

IDProjectCategoryView StatusLast Update
0001709DCP-o-matic[All Projects] Bugspublic2020-01-07 15:15
Reporteroverlookmotel Assigned Tocarl  
Status resolvedResolutionfixed 
PlatformMacOSOS XOS Version10.14
Product Version2.14.15 
Target VersionFixed in Version 
Summary0001709: Preview does not update with changes to crop/container for non-integer sources when trim end set

I think this is a repeat of 0001434.

I've been seeing this problem for ages (a year at least), but never managed to narrow down whether it was a bug in DCP-o-matic or something I was doing wrong. But I finally have a solid repro case, and it is a bug.


With non-integer frame rate sources (e.g. 29.97 fps), once you have set a value for end trim, the preview window does not update properly.

  1. Changing crop values is not reflected in preview. You have to step forward/backwards by a frame to see it updated.

  2. If you change container from Flat to Scope after setting end trim, the preview window remains Flat ratio, and remains so no matter how much you skip around the timeline.

Steps to reproduce:

Problem 1:

  • Create new DCP-o-matic project
  • Add a video file with non-integer frame rate
  • Set 'trim end' to 1 frame
  • Set 'crop left' to 100
  • Notice that there is no change in the preview
  • Step forward 1 frame
  • Notice preview now updates to reflect the crop

Problem 2:

  • Create new DCP-o-matic project
  • Add a video file with non-integer frame rate
  • Set 'trim end' to 1 frame
  • Change container from Flat to Scope
  • Notice preview remains in Flat ratio

Weirdly, if you save the project and reopen it, the problem disappears.

Carl, this can be reproduced with the same source file I have sent you for 0001708.

TagsNo tags attached.
Estimated weeks required
Estimated work required



2020-01-07 14:44

administrator   ~0003710

Great catch! Should be fixed by 535e22457facee1f7136d03741bcc7d27729ddc4 in master and dde431cafbb20ed3356ad5592be56af1d4458f46 in v2.15.x.


2020-01-07 15:13

reporter   ~0003711

Brilliant. Is the fix low risk enough to merge into a stable release?


2020-01-07 15:15

administrator   ~0003712

Yes it will be in 2.14.21.

Issue History

Date Modified Username Field Change
2020-01-06 21:46 overlookmotel New Issue
2020-01-07 14:44 carl Assigned To => carl
2020-01-07 14:44 carl Status new => resolved
2020-01-07 14:44 carl Resolution open => fixed
2020-01-07 14:44 carl Note Added: 0003710
2020-01-07 15:13 overlookmotel Note Added: 0003711
2020-01-07 15:15 carl Note Added: 0003712