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Audio strips sometimes are evaluated incorrectly
Closed, ResolvedPublic

Description

--- Operating System, Graphics card ---
Windows 7, x64, gtx 580

--- Blender version with error, and version that worked ---
r60958

--- Short description of error ---

We have a few 5-10 minute sequences with multiple audio strips (on different channels) fading in and out at certain times (animation of volume 0-1)... Sometimes, certain audio strips (not all) will either glitch up, or not play anything for their entirety.. the audio strips are around 30-50 meg wav files. Usually not all the audio strips glitch up, but only select ones.

This problem is also noticed in the mixdown option.. if the sequence has been messed up, the mixdown option will also reflect this.

I believe it has something to do with jumping to different frames during playback (by clicking on the sequencer view whilst it is playing back) and animation on the volume control.

Saving the file at frame 1, restarting blender and doing a mixdown from there usually fixes it.

If required, I can make an example blend file and upload it to a external host, the file will be quite large.

Carlo

Event Timeline

Can confirm it is still present in r61196

Joerg, feels like checking this one?

Sounds like the animation cache gets out of sync, can you please try hitting the "Update Animation Cache" button next time this happens and see if it helps? You can find it in the properties window -> Scene -> Audio panel.

Hi Joerg,

The 'Update Animation Cache' under the scene tab doesnt help at all. the only way to reset it is to reopen the file.

It is most noticeable during actual volume animation, so when the volume is changing from 0-1, if i am clicking around then click in the center of it, usually it glitches up then.

Hi,

the reason is that the animation system doesn't update the rna values anymore if the value actually didn't change. This results in the audio animation cache not being updated, so this bug appeared. The audio cache has a value for each frame and it's 0 if the data was never set and this results in a volume of 0 where there shouldn't be. To find the location of the problem: set a breakpoint is rna_squencer.c:628, then add a sound sequence in the sequencer, add a single keyframe and hit the "update animation cache" button in the props -> scene -> audio panel. The problematic line then is anim_sys.c:1343, that's where it checks if the value actually changed.

The change in the animation system not to update the rna makes sense, but this destroys the functionality of the audio cache as we can see here. Question now is how to fix this...

stay tuned

Thanks for the update Joerg. Seems like this is needing more then a small quick fix.

Yeah it was more. Fixed in revision 61239. After the start if the cursor is in the middle of a sound and you place it before that, but after the fade in, it might play silence still, but this can be fixed by the update animation button now or by just moving the cursor to the beginning and playing back from there!

Joerg Mueller (nexyon) changed the task status from Unknown Status to Resolved.Nov 12 2013, 7:31 PM

Thanks for the update, will test when the buildbot has been updated.

Just tested the latest buildbot, works as expected. thanks for the fix!