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Audio in Meta-Strips Plays Beyond Strip Cut
Closed, ResolvedPublic


This issue is somewhat hard to articulate, so please bear with me.

I have HD videos with audio tracks >
I set the audio volume to 0.000 because, USUALLY, I will not need the audio (though in some cuts I will) >
I then applied a Transform Strip to the video (to prevent them from distorting to the render dimensions) >
I created a Meta-Strip from these (combining the HD Video, audio, and Transform) >

So, I was slicing-and-dicing the new Meta-strip, cutting as needed. After a while, I got to the part where I needed sound for a cut. So, I:

Tabbed into the Meta-strip so that I could access its component parts >
Selected the audio strip >
Set the audio to 1.000 >
Tabbed out of the Meta-strip's Edit Mode

I placed my new cut where I wanted....and then this apparent bug was revealed: for some reason, the audio now plays for the ENTIRE strip. The specific cut where I needed the sound is only 5 seconds. The whole Meta-Strip is 2 minutes. Well, for some bizarre reason, when I go and set the volume to 1.000, now the volume plays over the entire length of the original Meta-strip, even though I now just have a five-second slice of it! I've tried everything I can think of to keep the audio limited to the 5-second cut its meant to be at, but this bug always plays the original strip's full audio.

Along this line, I would like to make the related request (though I know this is not the place for requests): For VSE Meta-Strips which contain audio tracks, please allow the Properties ("N") window to control the volume. You can control the Opacity of its component visuals, so it only stands to reason that you should be able to do the same with the audio. This would save much effort in always having to Tab into the Meta-Strip's Edit Mode.

I cannot attach a .Blend since Blender doesn't allow you to link video files into .Blends (plus this is a huge, messy file, as well.)

Thanks to everybody at Blender, as always, despite this frustrating issue.

Event Timeline

Please mention the exact blender version you used, and the operating system you tested this on?

And please do attach a .blend file if you can, at least for me it's very difficult to understand what exactly the setup is here. Even if it's just a .blend file without the actual footage (which you can include in a .zip if it's not too big), stripped to just the part that doesn't work, it helps a lot in debugging.

Okay. I will assemble a file within a few hours.

I've tried, but I cannot replicate this on a smaller file. The main file where the issue is present is very large and complex, and so that complexity probably plays a part in the cause of the bug. But I cannot attach that because both it and the video and audio files it's drawing from are huge.

I tried to pare down the file with the problem so that it could possibly be Zipped and shared. When I cut everything down except for the original video and audio file, then the Bug disappeared. It seems to only appear when there are many audio tracks and some complexity. But simply having one single Meta-Strip, cutting it, and then modifying the audio on one of the cuts, by itself, does not appear to be a problem. It's when there's a whole bunch more going on that it appears.

Could you please state the blender version you used, as Brecht already asked for?

Also just attach the complex blend file without the video file(s).

Windows XP
32 Bit
Blender 2.62
r 44136

I've also tried the most recent SVN, 45956, as well. The issue persists.

I've tried replicating the issue in small files multiple times and, unfortunately, I can't repeat it. But I also cannot fix it, no matter what I try, in the large file. I'm sorry that I cannot supply a .Blend.

Why can't you attach your blend file where the bug appears?

Because the component audio and video files are massive .AVI and .FLAC files, totaling well over 1 GB.

I didn't ask for those files, I just want the blend file.

Here is the .Blend:

Has the .Blend proved helpful in diagnosing the problem?

I just attempted a work-around of the issue by going into the Audio strip within the Meta-Strip and keyframing it.

This did not work. An "ERROR" message instantly popped up. I thought this might be useful in helping you diagnose the problem. So here is a screencap:

I have found that simply making the audio into a meta strip doesn't affect it, you must perform a copy > paste function.

Here is a a .blend with a failed fcurve in the first audio meta strip. A simple fade up from 0.00 worked until I copy and pasted it back into the timeline.

Sorry I am using win xp and b2.62 r 46007

That's VERY helpful, David McSween! I might even be able to work around this, now that I'm aware of that limit.

Yes the file was helpful in diagnosing the problem: to reproduce the bug you have to meta a sound strip twice as in your file!

The bug is fixed in revision 46035, so I'm closing this report.

The RNA problem you discovered too is another bug, please open a separate report for it, as this is animation system related, not audio related and has to be assigned to someone else, thanks!


Joerg Mueller (nexyon) changed the task status from Unknown Status to Resolved.Apr 28 2012, 3:18 PM

Thanks, Joerg. Will download the SVN for 46035 as soon as it's available (it looks like right now the latest one is 46008).

I know that you guys all do great work and, when we report bugs, we should be as specific as possible.

However, I just want to state that, over the course of editing a (fairly complex) 15 minute video, I have had SO MANY bugs with the audio that I literally couldn't even possibly describe them all here. This is especially true with keyframing the volume - both in Meta-Strips and just in regular strips.

Unfortunately, I can't do any coding myself. But I just want to say that I really think that the audio processes in the VSE - at least in the Windows 32-bit version - are INCREDIBLY buggy. It's so bad that I literally expect it to NOT work whenever I try to do anything.

So if anybody could commit to a serious overhaul of that, that might be very helpful to the VSE.

Despite this, of course, I'm still hugely happy with Blender and grateful to you all. Thanks!

Uhm, without knowing what's wrong, it's hard to fix any bugs, so even if you cannot code, you can report bugs, just start with the first three that appear to you for example.

However especially regarding keyframing audio: the current animation system blender has works fine for video frames typical FPS values, but audio has a much higher sample rate and that's why the animation system doesn't work well with audio. So there's an animation cache built between blender's animation system and the audio animation. So if you're editing keyframes a lot, you should make sure to press the "Update animation cache" of the Scene buttons as soon as you experience problems and check if it works then, see also the audio documentation, especially:


Okay, here is a screencap of two issues.

The first was just keyframing the audio of a simple cut clip (it was a two-minute clip cut from a two hour movie).

As you can see, I get an ERROR message and the volume won't keyframe.

Then, as a work-around, I tried exporting the audio track from the clip. That caused the program to instantly crash, 100% of the time. Here are screencaps:

Yet another bizarre phenomenon: trying to keyframe the audio, but two separate keyframes are always identical.

For example, let's say you want the audio to ease in. So, you set the first frame to 0.00. You then move to five seconds later and keyframe 1.00. But now you go back to the first frame, and it's ALSO 1.00! No matter what you do, they're always the same.

Here's the screencap of the issue:

First of all: please open a separate report for each bug, reporting in another bugreport is an organisational disaster.

Especially regarding the keyframing ERROR and same keyframes bugs, these have to be handled by other developers than me, as this is not my working area and I don't have the time to work into that.

Regarding the crash on exporting please also open a separate report and it would be nice if you could somehow get a backtrace or submit a blend file with the reproducible bug, otherwise it's impossible to track that one down.

Just to sum up: please stop posting in this report, open new ones!