60 fps video with 29.97 SMPTE lock

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Jarred91
Met Resolume in a bar the other day
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Joined: Fri May 22, 2020 08:29

60 fps video with 29.97 SMPTE lock

Post by Jarred91 »

Trying to see if I can solve this:

I have three simultaneous 60 fps videos that are being locked to SMPTE timecode coming from Ableton via audio cable. Everything is coming in fine (I can see that resolume is receiving SMPTE track) but when the SMPTE lock is enabled, the video does not appear to be 60 fps, it appears to be jittery/slower. My computer is handling it fine, the FPS readout stays between 59-60ish, and if I set one of the three clips to sync to the "timeline" rather than "SMPTE" that clip plays back at the distinguishable 60fps and the other clips look slower (looks even slower than 24-30 fps to my eye).

I am curious about the mechanics of the SMPTE sync. Is it possible that only half of the frames in my 60fps video is being played back because the timecode track is 29.97fps? Or maybe, does the SMPTE sync require more computer power and my computer just can't handle it? The latter explanation would surprise me because if 1 of the three clips is not synced to SMPTE it plays back smooth but the two synced clips play back jittery.

Here is a dropbox link to a screen record, the left performer is NOT synced to SMPTE and the right performer IS:

https://www.dropbox.com/s/q8x0kej0eklj4 ... N.mov?dl=0

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Zoltán
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Re: 60 fps video with 29.97 SMPTE lock

Post by Zoltán »

Jarred91 wrote:
Fri May 22, 2020 08:54
Is it possible that only half of the frames in my 60fps video is being played back because the timecode track is 29.97fps?
If you're using DXV, then that's exactly what happens. Resolume calculates the frame to display, based on the clip length, offset, and the timecode position, then seeks to the frame to show it. If you have a SMPTE signal half the frame rate of your clip, you'll only see every second frame of the clip.

If you're using mp4 or similar keyframed format, then try converting your media to DXV to get smoother playback ;)
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Jarred91
Met Resolume in a bar the other day
Posts: 2
Joined: Fri May 22, 2020 08:29

Re: 60 fps video with 29.97 SMPTE lock

Post by Jarred91 »

Helpful, thank you! The videos were originally .mov but were already converted to DXV. For fun I just now tried using the .mov file and as expected it was indeed choppy as it wasn't a DXV. Any ideas to get the the 60fps video to play back all frames when locked to timecode?

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Programfeed
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Re: 60 fps video with 29.97 SMPTE lock

Post by Programfeed »

Jarred91 wrote:
Sat May 23, 2020 17:58
Any ideas to get the the 60fps video to play back all frames when locked to timecode?
You'll need to conform the 60 FPS to 29.97 or whatever is exactly the frame rate of your incoming timecode. The longhand but easy way is to drop your native video into a new timeline with the target FPS in an editor like Premiere or Final Cut. Your situation going from high FPS to lower FPS should yield much better results than the other way around.

To add on to the discussion of DXV timecode chase... You might get away with the 60FPS file in a different media server that uses a Timeline to chase timecode rather than the server doing frame-for-frame read from the DXV file. But no doubt the best practice is to conform to your timecode FPS.

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