In September I became a planetarium director. It made sense, I'm a professional astronomer and have run shows using a couple of different Spitz projectors and even an old Zeiss. This was my first fisheye fulldome experience. Should be straightforward, right? The fulldome projector is offset from the dome center, however, because the Spitz is still in residence in its doghouse in the geometric center of the 44' dome.

The projector is a JVC SX21 D-ILA (native 1400x1050) so the "1K" circular image is 1024 across, but the controlling software is Konica-Minolta's MediaGlobe2. This is not a new system. It was about to be discontinued when the planetarium purchased it in 2009, in fact, so the MG2 software demands demuxed video-plus-audio of the pretty much antique m2v-plus-ogg format.

Our planetarium has almost no budget for content right now, since the board have had to repair the projector and take care of other deferred maintenance. In order to get "new-to-us" content I've been signing up for whatever free fulldome shows NSF or NASA or ESA funding has permitted to be offered to planetaria for educational showing. There is no separate fee for the planetarium shows, and the planetarium fills an informal educational role, hosting school field trips and the like.

OK, I've been able to locate some free shows that don't demand hundreds of dollars for "a hard drive to hold it, plus shipping and handling charges" (which is one way of charging something for a government grant-supported production despite the requirement that the grant-supported production be made freely available). [Seriously? These shows in 1K format are a couple of gig, you could stick 'em on a thumb drive or put them into dropbox...]  What is even more challenging from my POV is that the free shows are almost all distributed in more recent video formats. Usually as mp4 files. Hey, even that is OK, there are programs that will take an mp4 and demux it into an m2v-plus-ogg pair of files, BUT... the free one that does this well is a Linux program called ffmpeg.

So, copy files over to Linux machine, break mp4 into m2v-plus-ogg, note that the two files have the same run time when played separately, load into the Mediaglobe system using their very picky procedure, and boom, the files run but they start out ever-so-slightly out of sync and then as the ogg file plays at a perfectly steady and sedate rate, the video is farther and farther ahead of it! It's not a constant offset, it expands as time goes on, which suggests the sampling rate is off or the playback rate is off. The audio is not out of tune or compressed or otherwise weird-sounding, so this has got to be a problem with the m2v replay rate.

More later...

Views: 344

Comment

You need to be a member of fulldome.org to add comments!

Join fulldome.org

Fulldome Wikipedia Entry

Fulldome Video Discussion Group

IMERSA

Fulldome Database

Forum

Converting HD Video to Fulldome

Started by Dave Monk Apr 3.

The best Tools for Fulldome content creation 1 Reply

Started by Mike Lee. Last reply by Amr Ellaithy Oct 16, 2019.

Immersive Film Festival - IFF’19

Started by Antonio Pedrosa Jul 17, 2019.

help with conversion tool - won't communicate with PS 2 Replies

Started by Kimberly A Allard. Last reply by Andrew Hazelden Jun 14, 2019.

New To Fulldome Filmmaking And Need Some Advice

Started by Charl May 3, 2019.

Selecting a projector for Spherical mirror System 6 Replies

Started by Amr Ellaithy. Last reply by Joe Dunfee Mar 3, 2019.

KartaVR v4 for Fusion and Resolve Released

Started by Andrew Hazelden Jan 24, 2019.

Shooting fisheye lens, sensors - tips?

Started by Erika Tsuchiya Oct 27, 2017.

uh oh, i just joined... 1 Reply

Started by steve. Last reply by Alexander Hager Jun 12, 2017.

Stereoscopic domemaster images 154 Replies

Started by Roberto Ziche. Last reply by Andrew Hazelden Jun 10, 2017.

Latest Activity

Mark C. Petersen posted a blog post

FULLDOME OnDemand Adds Flat-screen HD Format Options

FULLDOME OnDemand has added a flat-screen option for customers to use when renting selected shows."Over the years at Loch Ness Productions, we've had inquiries about flat-screen versions of our shows, particularly for use in classroom settings," said Loch Ness Productions CEO Carolyn Collins Petersen. "Traditionally, we stayed focused on the dome experience; that's what we're good at, after all. Now with the worldwide…See More
Sep 1
James posted a blog post

Essential Tips For a Long and Lucrative Music Career, Wowessays.com review

Breaking into the music industry has always been a challenge for artists of all genres. Tens of thousands of artists are dying for meditation and gigs, and this is on top of the artistic challenge of finding inspiration for new songs, finding the right melody or beat, and tackling band member personalities. The entire process can be…See More
Aug 21
Dan posted an event

IMERSA Days at https://mailchi.mp/imersa/imersaday2

August 21, 2020 from 10am to 12:30pm
https://mailchi.mp/imersa/imersaday2Virtual IMERSA Days, August 21st and 28thFree registration!See More
Aug 19
Claudio Recabarren Madrid posted a blog post
Aug 10

© 2020   Created by Dan.   Powered by

Badges  |  Report an Issue  |  Terms of Service