Work at SourceForge, help us to make it a better place! We have an immediate need for a Support Technician in our San Francisco or Denver office.

Close

#205 speed effect >100% ends with frozen frames, also clips off image parts

trunk
closed
nobody
None
5
2014-04-13
2014-02-17
TheDiveo
No

Okay, finally I'm reporting what I consider to be a bug and that has bitten me so many times... (not hard enough obviously)

  1. In one of my projects I do a timelapse scene from part of a H.264 clip shot at 25fps, by setting the speed effect to 1200% (12x speedup). This scene can be seen from 00:00:14 to 00:00:18 in this video: https://www.youtube.com/watch?v=cYHCrAF0vUI on YT. Around 00:00:17 the rendered frames freeze and are repeated. However, the original clip from which this scene is taken has many more frames, so there is no reason to repeat the same frame over and over again.

  2. With the newest (Kdenlive/MLT) nightlies from 2014-02-17 there is an ugly interaction between the zoom and pan effect and the speed effect: it causes size and position to be miscalculated so I get a big black bar at the top; it looks as if this black bar is actually a part being clipped off without being told to do so.

Discussion

  • Dan Dennedy
    Dan Dennedy
    2014-02-17

    I was not able to reproduce #1 with some files I tested on. The speed effect is highly dependent upon the seeking capability of libavformat and your file type. I am not working on improving seeking at this time. I recommend that you transcode your clip to something like DNxHD or Lossless Matroska before attempting to apply the speed effect.

    I am also unable to reproduce #2. I tried both a static pan/zoom and an animated one. I was zoomed in for both tests. It might be related to #1.

     
  • Dan Dennedy
    Dan Dennedy
    2014-04-13

    • status: open --> closed
     
  • Dan Dennedy
    Dan Dennedy
    2014-04-13

    Closing as unable to reproduce, and this effect is highly dependent upon seeking capability in libavformat, which is highly dependent upon file format and tool which created the file. IOW, it works for some well known files with no temporal compression (e.g. DV). Your mileage may vary, and you (or the app) should consider only to use his effect on clips with known reliable format.