APS Excellence in Physics Education Award
November 2019

Education Prize Logo
Science SPORE Prize
November 2011

NSF Logo
The Open Source Physics Project is supported by NSF DUE-0442581.

can't export video clip post and replies

Return to the can't export video clip thread
Login to post to this thread

java exceptions
Gordon Judd
11 Posts

I am unable to export the finished video file I have made that tracks three points on  an .mp4 file.  A listing of the java exception errors I am getting is attached.

Attached File: tracker_exception_error.jpg


Replies to java exceptions

Re: java exceptions -
Douglas Brown Avatar
Douglas Brown
452 Posts

Thanks for the bug report, Gordon. The ExportVideoDialog exception may be caused by saving the exported video without an extension. If that is the case, try assigning an appropriate extension to the filename when saving and see if that works. And please let us know either way what you find.  Doug


> I am unable to export the finished video file I have
> made that tracks three points on  an .mp4 file.  A
> listing of the java exception errors I am getting
> is attached.



Re: java exceptions -
Gordon Judd
11 Posts

Thank you for your quick response.

My original video was taken with a Casio EXF1 camera to produce a 512x374 pixel resolution  at a frame rate of 299.7 frames per second and contained 257 frames.  Its file size was 529 kBytes.

Adding either a .mp4 or .mov extension to the file name got rid of the java exception errors but the resulting exported clip is very fuzzy (even though it was saved with a 512x374 resolution) and plays back so fast it no longer is in slow motion even though it also has 257 frames.  The exported video clip size is only 192 KBytes.  A screen grab from the exported clip is attached so you can see its degraded resolution.

What can be done to maintain the properties of the original file?

Attached File: tracker_screen_grab.jpg



Re: java exceptions -
Douglas Brown Avatar
Douglas Brown
452 Posts

Unfortunately there is nothing to be done about the resolution, but the playback speed can be controlled by adjusting the play rate (white field in the video player bar).

Question: when you open the exported video and look at its properties, is the frame rate already 299.7 by default? If so, you might try opening the clip settings (5th button on the toolbar) and setting the frame rate of the original back to 29.97 or 30 fps before you export it.

Hope this helps!  Doug


> My original video
> was taken with a Casio EXF1 camera to produce a 512x374
> pixel resolution  at a frame rate of 299.7 frames
> per second and contained 257 frames.  Its file size
> was 529 kBytes.
>
> Adding either a .mp4 or .mov extension
> to the file name got rid of the java exception errors
> but the resulting exported clip is very fuzzy (even
> though it was saved with a 512x374 resolution) and
> plays back so fast it no longer is in slow motion
> even though it also has 257 frames.  The exported
> video clip size is only 192 KBytes.  A screen grab
> from the exported clip is attached so you can see
> its degraded resolution.
>
> What can be done to maintain
> the properties of the original file?



Re: java exceptions -
Wolfgang
192 Posts

Please try one of our online examples.  I was able to export the Projectile example in the Tracker Digital Library examples directory without difficulty.  I am using a Mac running macOS Monterey.



OSP Projects:
Open Source Physics - EJS Modeling
Tracker
Physlet Physics
Physlet Quantum Physics
STP Book