Author Topic: [IMPOSSIBLE] dual ISO H.264  (Read 70927 times)

Audionut

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Re: [IMPOSSIBLE] dual ISO H.264
« Reply #150 on: August 20, 2014, 02:46:59 AM »
Try growing mushrooms instead!

tweak

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Re: [IMPOSSIBLE] dual ISO H.264
« Reply #151 on: August 20, 2014, 02:48:48 PM »
Mushrooms are easy to grow, they grow by themselves on the roof of my bathroom.

cmccullum

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Re: [IMPOSSIBLE] dual ISO H.264
« Reply #152 on: July 11, 2015, 09:53:47 PM »
Soooooo lost in this thread!
Anyway, I have an idea (briefly tested without sound) for processing H.264 Dual iso! Here goes:

1) Import dual iso footage into NLE
2) Double speed of footage
3) Export footage at double the original frame rate
4) Re import footage
5) Decrease speed 50%
DONE!

In my brief testing, the only potential problem I noticed was a slight choppiness to the end result, but I'm sure someone could use this type of workflow to get some useable results …maybe?

Audionut

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Re: [IMPOSSIBLE] dual ISO H.264
« Reply #153 on: July 14, 2015, 01:54:07 AM »
How does changing the frame rate, change exposure?

Conaxe

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Re: [IMPOSSIBLE] dual ISO H.264
« Reply #154 on: July 14, 2015, 07:11:18 PM »
This method sounds to good. @cmccullum would you like to answer my question from your thread?
70D.111B

cmccullum

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Re: [IMPOSSIBLE] dual ISO H.264
« Reply #155 on: July 25, 2015, 12:48:39 AM »
@audionut as far as I can figure, it isn't actually changing the exposure, but causing the flicker to happen so rapidly that it can't be seen (or registered by premiere?). I don't know why the flicker doesn't come back when the new clip is slowed down though. This is just something my crazy brain thought up. If anyone could explain this further, please do!

@conaxe I can't find my thread  :-\ it may have gotten deleted for some reason. As you can see I'm brand new to the forum, and this is actually the first online forum I've ever participated in

Edit: after reading over my post again, I figured out why I even had this idea and why I think it works:
When the speed of the original clip is doubled, the two alternate ISO frames are squished into the space of one frame. In the original timeline, these are "seen" as two condensed frames, but when exported at double the original frame rate, they are read as one frame and joined somehow.
Ex: a 300 frame 24fps clip takes up 300 frames in a 24fps timeline. Double the speed, and you have 300 frames taking up 150 frames in the timeline. Export that clip at 48fps and you now have a 150 frame clip. Bring that clip in to the 24fps timeline, and expand those 150 frames to take up 300 frames worth of time.

To be honest, this could all be complete nonsense. I've still only tried it one time with one clip the moment I got the harebrained idea, but if we do some more testing, and find it to be a viable workflow, it shall be dubbed DUAL ISO FRAME FUSION!!

dmilligan

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Re: [IMPOSSIBLE] dual ISO H.264
« Reply #156 on: July 25, 2015, 05:07:42 AM »
What you are describing is not "Dual ISO", it is called "HDR Video" there are plenty of existing workflows for processing it properly.

"Dual ISO" is interlaced ISOs within a single frame, "HDR Video" is alternating ISO from frame to frame. It's easy to recover h.264 "HDR Video", it's impossible to recover h.264 "Dual ISO".

cmccullum

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Re: [IMPOSSIBLE] dual ISO H.264
« Reply #157 on: July 25, 2015, 06:47:59 AM »
@dmilligan I used the dual ISO module, and alternating ISO frames is what I got. Im definitely not saying you're wrong, but as far as I've understood, everyone talking about dual ISO videos has been dealing with the same thing. Am I misunderstanding all of this?

Audionut

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Re: [IMPOSSIBLE] dual ISO H.264
« Reply #158 on: July 25, 2015, 07:32:01 AM »
Read about dual ISO, and read about ML HDR video.

When you have a clear understanding about both exposure methods, all your misunderstandings will be cleared.