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Sequencer : Speed Control visualization
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Authored by Lucas Boutrot (thornydre) on May 19 2019, 5:57 PM.

Details

Summary

Hi,

I was editing a video, and using the Speed Control effect strip, but I couldn't visualize where my strip ended, so I tried to make this patch.

I have one issue though, I wanted the black part to have an alpha value so we can see what's behind it, but the alpha value I put in immUniformColor4ub doesn't seem to work. Maybe should I use something like UI_GetColorPtrShade3ubv(background_col, background_col, -20); ?

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Repository
rB Blender

Event Timeline

I like this idea, but this task is more complex than you may think it is.

For example your patch works only with "multiply speed", ignoring "speed factor" and also frame remapping feature, which honestly even I don't know how it works off top of my head.
Add to this that source strip can be soft cut, hard cut and reversed.
This is still possible to account for, it's just a lot of work. Example of similar attempt is D3496: Scale & stretch & cut sound waveform, which still is nowhere near perfect.

However speed property can be animated in such a way, that you can remap any frame of source to any frame of speed effect. This is near impossible to visualize.

In _near_ future there is plan to make it easier to work with time-stretched strips and property animation preview directly in timeline.

I don't want to discourage you however.
Personally I use speed effect often, and I hate it.

The direction I would go now is to simplify default settings, so:

  • you enter 1 number, and that will be the speed multiplier
  • change length automatically (click to override this)
  • bonus points for support audio + video strip for one speed effect (audio will be hackish, but for good cause?)

I believe this is most frequent use-case and also default for most apps.
If you want to do this I can help you.
If not I will probably do this myself when I will have time.

Hey,

Thank you for your answer ! :)

I see what mean, indeed it is a bit more complex than what I did haha.

I can have a try with what you are proposing, so if I understand correctly :

  • Removing the options Speed factor and Frame number from the Speed Control effect ? And keep only the Multiply speed option ?
  • Change length automatically, so that would be what I proposed or a bit different ? With a checkbox to disable it ?
  • I can have a try with the video + audio support.

I will definitely have a try with this task, it doesn't seem too much for a beginner :)

Thanks for your help !

would be awesome if it would also include in text form on what frame the clip ends now.

  • Removing the options Speed factor and Frame number from the Speed Control effect ? And keep only the Multiply speed option ?

I meant:

  • use mode "use as speed" by default
  • don't use "Speed factor" in this mode

Not sure if other modes are useful, therefore I don't want to remove them or modify their behavior

  • Change length automatically, so that would be what I proposed or a bit different ? With a checkbox to disable it ?

Yes. When creating this effect there is no animation on it so it's safe to do so.

Automatic length change will still produce invalid results in some cases, but the same applies to merely applying speed effect, so I can live with that.

  • I can have a try with the video + audio support.

I will definitely have a try with this task, it doesn't seem too much for a beginner :)

I would advise to do this changes one by one.

Thanks for your help !

You are helping me, so thank you :)