Strips overlapping in VSE
Closed, ResolvedPublic

Description

System Information
Windows 7, 32 bits; Radeon graphics card (but this is not a graphic card error)
*I can test on a Debian Stable 64 bits with nVidia if needed

Blender Version
Broken: 2.76 48f7dd6
Worked: all previous stable releases since... 2.68 maybe?

Short description of error
Strips are overlapping (being placed over each other) when using means that are not Grabbing (G).

Exact steps for others to reproduce the error
You shouldn't need a .blend file from me to reproduce this error. Exact steps are:

  1. Add a movie to scene; it is important that you add a video with audio. Now you have:

1 audio (channel 2)
1 video (channel 1)

  1. Shift+D and duplicate the video; place it exactly above the original video. Now you have:

1 audio (channel 4)
1 video (channel 3)
1 audio (channel 2)
1 video (channel 1)

  1. Select your audio strip (channel 4) and, on the strip data panel, change its channel to -1 (say, from 4 to 3). The strip immediately goes to channel 1, overlapping the video strip is there. The same happens if you do these steps with the video from channel 3.
  1. Now this is interesting. Undo the changes and go back to step 2. Select the audio strip (channel 2) and change its channel to 1. The audio strip recognizes that a video strip is there and is placed after it, instead of over it.
  1. The same happens if you do these steps with python.
  1. Curiously, this does not happen if you Grab (G) the audio+video strips and place them overlapping the other - they will recognize the former and be placed before or after it. This was the default behaviour in Blender in all previous releases.
flavio (flavio) updated the task description. (Show Details)
flavio (flavio) raised the priority of this task from to Needs Triage.
flavio (flavio) set Type to Bug.
flavio (flavio) added a subscriber: flavio (flavio).

Hi, just to add two infos:

  1. Tested and behaviour is the same on a linux Debian Stable machine, nVidia graphics card.
  1. I'm trying to trace back when this behaviour in the strips changed and apparently, it was ok until Blender 2.73 (always release version). In the change to Blender 2.74 this started happening and kept until now, so contrary to what I said, it's not specific to 2.76 - even though it would be nice if it could be fixed.

cheers!

Sergey Sharybin (sergey) triaged this task as Normal priority.Nov 3 2015, 11:36 AM

Can confirm the issue. Think it's just matter of searching empty channels in both directions or maybe not doing anything if the empty channel is found when shuffling the strips?

@Julian Eisel (Severin), really close to what you did for node offset, mind having a look here? :)