Celestia Forums

How can I export videos with maximum (the one!) quality in Celestia? What codecs, or other things, you recommends?

Anybody help me?

Thanks for all

Uncompressed will give you the best quality but it makes a huge file.
I usually use the Xvid compression. The quality isn't as good as uncompressed obviously but it doesn't make this monster sized video files.

But the size of file is restricted to the quantity of memory no?

Well yes if you have a big hard drive then you can make the videos as big as you want.

Ok, but here, in my CPU (HD 500GB), the size of files never are more than 4GB (system memory). The video data captured by Celestia don't are storage in system memory before write in HD?

Sorry by the poor english. And thanks for your patience.

If you select uncompressed, each frame is written one after another to disk. Only one or two frames have to be in memory at a time. Each frame is about 4 MegaBytes.

Some compressed movie formats compare several frames and only write the changes to disk. They need to keep several frames in memory.

In both cases, the entire movie does not have to be in memory. The size on disk can be many, many gigabytes, much larger than main memory.

Some old software was limited to 2 or 4 GigaBytes because of the way it was written, using 32 bit integers. Modern software does not have that problem.

igorborgo wrote:Ok, but here, in my CPU (HD 500GB), the size of files never are more than 4GB (system memory). The video data captured by Celestia don't are storage in system memory before write in HD?

Sorry by the poor english. And thanks for your patience.

Perhaps do you intend convert the monster file AFTER it has been captured? This is not the right, fast operation. You may set the compressor BEFORE to capture the video. Once you have made this operation, Celestia will write the file already compress, saving the HD space.

Some old software was limited to 2 or 4 GigaBytes because of the way it was written, using 32 bit integers. Modern software does not have that problem.

I think that what is happening here. But when you say old software, as the old means?


I'm having doubts because such use of celestia videos to produce educational videos here in Brazil and I think I have not found a codec that matches the quality of my needs. What better meets my requirements is that Divx, Xvid have played well but did not see much difference. Any other suggestions?

And thanks again.

How large is your computer's paging file? That might be what's causing the limit you see.

Here's the procedure for XP. Vista should be similar.
login as administrator
right click on My Computer, select Properties (at the bottom of the popup menu)
select Advanced tab
select Performance Settings button
select Advanced tab
select Virtual memory Change button
select Custom size
set Initial Size to be 16000
set Maximum Size to be 16000
select OK buttons until all windows close.
reboot

Don't forget that higher quality = larger files.
I'd suggest having Celestia record its movies uncompressed.
Divx and xvid throw away quality to make the files smaller.

You can use commercial movie editing software to edit Celestia's output files and write to a more appropriate display format. Adobe Premiere is one example. It's expensive, but there are educational discounts. Windows Movie Maker might be able to handle the large files. Its proprietary WMV format usually has reasonable quality.

selden wrote:
...

You can use commercial movie editing software to edit Celestia's output files and write to a more appropriate display format. Adobe Premiere is one example. It's expensive, but there are educational discounts. Windows Movie Maker might be able to handle the large files. Its proprietary WMV format usually has reasonable quality.

A good FREE and small video editor with lot of the same Premiere functionalities, including plugins, is VirtualDub:

http://www.virtualdub.org/index.html

On Windows, Celestia uses Video For Windows for video capture. This is limited to 2GB file sizes. The maximum size of a video written by Celestia doesn't depend on RAM--the video frames are written to disk as they're captured.

--Chris

Thanks to all the information. Hardly able to export smaller files that mentioned the 2GB as Chris. Because my videos are not as tight. I will continue exporting the videos with the same Divx or Xvid, since this will be the highest quality that can benefit from Celestia to produce the DVDs with the educational videos. Selden, I will try to increase the paging file and see if something changes here ...
As the edition, already use the premiere to a long time, also use the Encore and Audition. Also've played VirtualDub. The production of videos is a project sponsored by the brazilian federal government and aims at training teachers across the country.

Thank you for the help of you, is of great value.

Igor Borgo.

igorborgo wrote:How can I export videos with maximum (the one!) quality in Celestia? What codecs, or other things, you recommends?

Anybody help me?

Thanks for all

For saving video's on a computer losslessy I recommend the following:

For audio the solution is relatively simple: flac. (free lossless audio codec)
Flac already exist for a while and much software supports it.
(I recommend using ogg as a container)

For video it's a little harder, not much codecs support lossless compression
but a new codec named Dirac says it can compress lossless.

It doesn't loose information compared to the raw data and is compressed using wavelets,
that makes small files compared to the methods that most current codecs do (discrete cosine transform).
And much smaller files than the raw, uncompressed data.
The downside is that not much software supports it yet. (Celestia currently doesn't support it.)
So I haven't seen it in action yet.

(I recommend using ogg or mp4 for encapsulating Dirac, it is also supported in mpeg2)


And for container I recommend matroska (it can contain anything) and, or ogg container.