HDR Video: Avisynth and AE workflow videos different lengths?

Started by lifeartpixels, July 22, 2015, 04:14:23 AM

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lifeartpixels

Hi there,

I was testing the Avisynth vs the After Effects workflow of converting the flicker-HDR-video to useful footage, and found that the video that came out of Avisynth has a different length than the one that came out of After Effects.

Details:
Original video length was 8 seconds. The video I got out of After Effects using the After Effects workflow was 8 seconds as well. The video i got out of Avisynth was 17 seconds. Using a Canon 600D, Magic Lantern 2.3. Video was shot at 59.94fps, after converting 29.97 fps.
I use this workflow in After Effects: https://www.youtube.com/watch?v=bdtLZUS92Vw  (skipped the twixtor part since I recorded at 60fps and 30fps is fine by me.)

Why is the video doubled in length after using the Avisynth HDR workflow? Does it render in extra frames? Or does it first, instead of overlapping the light&dark frames one-on-one, copy a light frame over each dark frame, and a dark one over each light one >> making it double the length like that?

Im just curious. So far it seems the Avisynth method is less time consuming, but what do you guys think is the method to get the best quality?

DeafEyeJedi

I like AE's workflow better since that's what I'm used to. However, another app worth noting is @Danne's 'cr2hdr-r' which works really well on Mac's for HDR Raw but apparently you are running Windows, right?
5D3.113 | 5D3.123 | EOSM.203 | 7D.203 | 70D.112 | 100D.101 | EOSM2.* | 50D.109

glubber

I guess you're talking about the HDR-workflow-051.zip?

It's been a very long time since i last used it, so here is my guessing:
Did you choose the wrong frame rate in virtualdub (video/ frame rate)?
The script assumes the frame rate to 25 fps.

Normally the resulting frame number is reduced to half, i.e 480 frames result in 240 A and B frames, getting merged to 240 C frames.
EOS 550D // Sigma 18-200 // Sigma 18-70 // Canon 10-18 STM

lifeartpixels

@DeafEyeJedi
Yeah but the AE workflow does take more manual labor.  And yeah my editing computer is windows, got a Macbook Pro too but that is sorta slow for editing video.

@glubber
Correct, thats the workflow i was referring to.
Yeah, it was on 25fps indeed..

I was now just testing what would happen if i shot 1080P 30fps footage and ran it through the hdr workflow to be 25fps final video, actually looks pretty good to me.. or are my eyes misleading me or am i missing something? Is it important to keep the fps correct in Avisynth, and if so, should it be (if originally shot at 60fps) 30, or 60fps filled in here?

Here's the thing: I'm working with a 600D and when i shoot indoor HDR video i am sometimes forced to use iso1600, which looks completely terrible, noise all over.

I used to always work with 60fps when doing HDR, on a 120th shutter. But since the noise is so extreme on 1600iso i thought i should try it on 30fps with a 60th shutter to save some light. 60fps with a 60th shutter is not really recommended, is it?


Thanks in advance for your help guys, appreciate it


lifeartpixels

btw DeafEye, i see you are referring to RAW hdr, at least i assume since i see cr2 hdr in the post.. i am not shooting raw hdr i think, it comes out of my camera as a normal .mov file. Is it possible to shoot raw hdr on a canon 600d? that would be cool to experiment with, i am assuming it will crank down the noise in higher (800/1600) iso ranges a lot?

Danne

Cr2hdr-r, it is an automated script workflow for mac. It uses user jerrykils script to create .mov sequences from hdr files, both filmed in h.264 and raw/mlv files.

lifeartpixels

ah ok i see, so its similar to the hdr workflow using avisynth and virtualdub, but mac-workflow?