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Does anyone besides me use the movie record function?

Posted: 20.03.2019, 18:20
by Janus
In the past I have used a highly modified version of celestia to record things like my solar system tour.
To accomplish it, I used brute force tweaks, which were inefficient and ugly.

The problem in celestia is that scripts {celx} have a clock unrelated to the simulation clock.
This meant that while you could record your own movements easily.
Trying to record a script which you just watched work perfectly, would fail because they would come out of sync.
Which has prevented prerecording of presentations using celestia.

I found this because while system could handle 200+ fps, I was recording at ~30fps.
Because of the way celestia works, it was trying to record at 200+ fps, with the simulation clock advancing a frame slice.
Or to put it simply, the simulation was advancing its clock 1/30s @ 200+ times per second.
I got around it via brute force, it had no elegance.

I was able to come up with a new way to keep realtime sync.
While it is not as nice as having the scripts use the simulation clock, something I am still working on.
What it does is only record at the capture rate, regardless of the display rate. {Celestia calls the frame capture each tick.}
Therefore, a ten minute script, will require ten minutes to record.
Recording at greater or lesser than realtime will require celx to use the simulation clock.

This tweak requires you to respect nyquist though.
Which means if you want a stutter free recording, your system must support a minimum of 2*fps you want to record at.
My project {Solar system tour DVD}, which I recorded at ~30fps, requires 60fps{Toggled visibility in the lower left when you press the tilde '~' key.}
Any lower than that and you risk frame drops.
If anyone uses this, let me know how it works for you.


P.S. also includes all of my other recently posted tweaks such as betwixt, betwixdex & benear.

Posted: 21.03.2019, 07:15
by Lafuente_Astronomy
Janus wrote:P.S. also includes all of my other recently posted tweaks such as betwixt, betwixdex & benear.

I don't really do the "Capture Movie" function, but does it contain the Legacied, 1GLY, 2M and Hubble versions as well?

Posted: 21.03.2019, 08:00
by Janus

Yes, almost anyway, commit 5429 is the version I am currently using for experiments in bringing my work arounds and other mods forward.
It has all of the stuff I have put up with 5429 in the name included.

It does not contain the 2M star database because that is in the data directory, and this is just the exe files to run.
You can look in My Downloads for the archive(s) with 2M in the name if you want that.


Posted: 21.03.2019, 09:10
by john71
I use Xvid MPEG-4 codec in 1080p mode with minimum compression to record movies. Celestia creates good video production material.

Use Shotcut to edit the video (saturation, contrast etc.).

Posted: 21.03.2019, 14:36
by Janus
I generally use lagarith, an open source lossless codec.
It supports multicore/multithread and has low overhead.
I eats storage however, but I am fine with that.

What editing I do is typically done in my tweaked version of virtualdub.
I am working on bringing it forward so I can compile it in VS2015.
After that I will add making mkv files to it.
Of course I am also working on a fork of Celestia that creates mkv files directly.

Then I either run through handbrake to make an mkv, or dvdstyler to make a dvd out of it.

I often have to make an avi with xvid out of things so people/customers can use older equipment to play them.
Concerns about over functionality leading to security vulnerabilities is common I have found.
Giving them files that can be played by stupid/brainless video appliances that don't even know what a network is eases their real world concerns.


Posted: 21.03.2019, 15:50
by john71
Virtualdub is good, but Shotcut has multitrack video editing capability. So you can make a real movie out of Celestia, containing multiple shots and different live video effects per partial cuts.

Posted: 21.03.2019, 16:10
by Janus
I will be trying out shotcut after I get caught up on my current job.
Sales people should be banned from making promises not countersigned by their IT departments.
Then people like me get to try to figure out if the glitch is a misunderstanding, an undocumented behavior, an unwanted feature, or worse, sales speak.

I also do not do fancy video stuff, just basics.


EDIT: Fixed spelling.