Celestia Forums

I'm working on an educational script that I would like to capture as a video. I tried to use Celestia 1.4 internal video capture, but the result is not good enough : I need a (nearly) professional quality video.

I tried with all codec, and even with no compression, but the rendering remains very "jerky". I don't think it's a setup problem, and I'm not a newbie at video capturing and editing...

Here's my system configuration :
2 GHz AMD Athlon with XP Pro
512 Mo RAM
NVidia GeForce MX 440SE with AGP 8X

Do you think I will get best results with adding more RAM ?

I could always use an external D8 recorder but I'd like to know if Celestia can make it...

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Vincent

Vincent wrote:I'm working on an educational script that I would like to capture as a video.

[...]

I could always use an external D8 recorder but I'd like to know if Celestia can make it...

Can you elaborate on the external D8 recorder option? At the planetarium I work at, we would like to create Celestia movies by recording the ouput of the PC's graphics card via some sort of external capture device or board.

We briefly discussed this with some video experts, and we were told that this is possible, but image quality is limited. But maybe their "low quality" may be acceptable for our purposes.

Any suggestions on equipment? Price may not be an issue.


Paolo Amoroso

Could the timing irregularities be due to loading textures or models?

Celestia is uses single-threaded I/O, not asynchronous, so you need to do at least one run-through of the script ahead of time to get everything loaded into memory.

selden wrote:Could the timing irregularities be due to loading textures or models?

No, because as I did in the Deep Impact Mission script, I always write a few lines to load and display my objects (textures and models) at the beginning of the script. And then, as you suggested, I always run my scripts twice before capturing the video.
The problem is that the captured video is always EXACTLY TWO TIMES FASTER than the original script, as if Celestia only saved one frame out of two.
I managed to deal with that by making a two times slower version of my scripts. It's a lot of work, but it works !

amoroso wrote:Can you elaborate on the external D8 recorder option?.

The problem with the internal capture device is that Celestia has to read the script and display objects, which already takes a lot of ressources, and then to capture frames and save them on the disk at the same time.

As as wrote above, you can deal with that by making a two times slower version of your scripts.
I also use the excellent Huffyuv video codec for Windows. Contrary to the DivX codecs, the image quality is good and the captured videos can be used in Premiere or any other video editor without crashing.

Huffyuv video codec can be found here :
http://www.divx-digest.com/software/huffyuv.html


Then, if you don't want to write scripts to capture your videos, you can use an external video capturing device :

- With the D8 recorder, you can write a digital quality video on a tape. You can use a Svideo cable between your video card line out and the D8 recorder. Then you can put the tape in any D8 camcorder and capture it in your computer via your IEEE card (or your video card).

- To get the best image quality, you can use a second computer to directly capture the video. The first computer run the Celestia sequence, and the second one captures the movie. Make sure the second computer has a Svideo line in interface on the video card. You can use a Svideo cable between the Svideo line OUT of the first computer and the Svideo line IN of the second computer.

I hope that will help you in your projects ! Tell me if you still have any trouble.

E per finire, in bocca al luppo !