Author Topic: LIVE: SpaceX Falcon 9 Static Fire - April 30, 2012  (Read 80697 times)

Offline Garrett

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Re: LIVE: SpaceX Falcon 9 Static Fire - April 30, 2012
« Reply #300 on: 05/05/2012 04:58 PM »
Okey Dokey, I get you now.
- "Nothing shocks me. I'm a scientist." - Indiana Jones

Offline benjaminhigginbotham

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Re: LIVE: SpaceX Falcon 9 Static Fire - April 30, 2012
« Reply #301 on: 05/11/2012 11:28 PM »
Sigh. The fact there are N frames per second encoded in the video does not mean there are N unique frames. For example, I can easily generate a 30 fps video which duplicates every frame and thus has an effective frame rate of only 15 fps.

I don't have to look past the actual video to see it's not full motion and if you were shown the original footage side by side, you'd notice it too. NASA's Ustream channel does not webcast at full framerate, whereas the old NASA Windows Media streams did. They made a step back in my opinion.

While this is technically correct (assuming you mean 29.97fps and not 30fps), it is not how most of the SpaceX sources nor encoders work. If you're not seeing 25fps+ video, then you have an issue in decoding the stream. Try enabling/disabling your GPU acceleration in flash. The SpaceX stream is also MBR now, so you may want to try a lower quality if your system can't keep up for some reason. The player is supposed to automagically select the right stream for you, but if you're right on the cusp it may pick incorrectly. Having the latest version of flash always helps as they keep fixing issues with the stage and GPU offloading.

A very recent change was made to get the HD video more fluid and closer to 29.97fps rather than 24/25fps for launch itself. 60fps (59.94) is a bit excessive for web video. It would be cool, but the playback requirements go too high for most users. Same with 1080p unfortunately.

And here's a niffty little tip I'm not sure everyone knows... There is DVR now ;)
« Last Edit: 05/11/2012 11:30 PM by benjaminhigginbotham »

Online ugordan

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Re: LIVE: SpaceX Falcon 9 Static Fire - April 30, 2012
« Reply #302 on: 05/12/2012 10:40 AM »
Having the latest version of flash always helps as they keep fixing issues with the stage and GPU offloading.

It's definitely not that. I've tried everything from lowering quality to lowest, playing it offline with other decoders, to checking out other recorded sources (including NASA's forwarded webstream) and they all "stutter" at identical timestamps indicating this is really present in the stream going out of Hawthorne (?).

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A very recent change was made to get the HD video more fluid and closer to 29.97fps rather than 24/25fps for launch itself.

This, I *think* is the crux of the matter. If you were doing this, decimating 30 fps (OK, 29.97 source video) by a non-integral factor (i.e. everything other than 15 fps, 10 fps) you're bound to run into this kind of skipping. To some people it's not noticeable, but to others the motion discontinuities are among the most annoying video artifacts there are.

Lest I only be criticizing the webcast, I will say that the image sharpness was noticeably better than on the previous launch and pad camera aspect ratios were good.

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60fps (59.94) is a bit excessive for web video.

Oh, I definitely agree. While it would make engine plumes dance around more happily, it's definitely overkill for everything else including player performance requirements.

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There is DVR now ;)

Yep, and it's a very cool feature. Something I haven't seen with any other launch webcasts yet so kudos for implementing it.

Offline MP99

Re: LIVE: SpaceX Falcon 9 Static Fire - April 30, 2012
« Reply #303 on: 05/12/2012 11:30 AM »
There is DVR now ;)

Yep, and it's a very cool feature. Something I haven't seen with any other launch webcasts yet so kudos for implementing it.

Agreed - very cool.

Used it myself, but it wouldn't let me wind back once the broadcast finished. I don't know, but wonder whether it would have cut me off if I'd been chasing at that point.

cheers, Martin

Offline corrodedNut

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Re: LIVE: SpaceX Falcon 9 Static Fire - April 30, 2012
« Reply #304 on: 05/14/2012 05:38 PM »
Here's another photo from the static fire roll-out:

http://spacexlaunch.zenfolio.com/p423974353/h161c24be#h161c24be

Don't think this image has been posted on the forum yet. Make sure to browse the rest of the site, it has some good stuff (thanks, Ugordan)

Offline kevin-rf

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Re: LIVE: SpaceX Falcon 9 Static Fire - April 30, 2012
« Reply #305 on: 05/14/2012 07:11 PM »
I like that picture, only problem is, POINTY SIDE UP ;)
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Offline Comga

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Re: LIVE: SpaceX Falcon 9 Static Fire - April 30, 2012
« Reply #306 on: 05/16/2012 03:39 AM »
Here's another photo from the static fire roll-out:

http://spacexlaunch.zenfolio.com/p423974353/h161c24be#h161c24be

Don't think this image has been posted on the forum yet. Make sure to browse the rest of the site, it has some good stuff (thanks, Ugordan)

I agree.  Thanks!

The solar panel pontoons are not lined up with the strongback, the base of the rocket, or with the Dragon capsule.  This is a bit of unusual asymmetry.  My guess would be that the solar panel anchors / roll joints are on the "centerline" and the panels extend from there.  Perhaps the panel closest to the second stage is not "half sized" as depicted, or perhaps the half sized panels and the hinge together are as wide as a full panel, displacing the center.   I look forward to seeing images of them deploying (I hope) and deployed. 
What kind of wastrels would dump a perfectly good booster in the ocean after just one use?

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