Blackmagic Forum

I digitized some super 8mm film. Its in MP4 format now. my understanding is super 8 was captured 18 frames per second. If I wanted to change the frame rate, I would do that when I rendered?

The last time I used resolve I was on version 18, I upgraded to 20 and I am struggling to remember the little I knew in the past.

Why do my files get smaller when I render? they shrink down to half the size. how do I render and keep the same file size? how do I not compress in the render?

Firstly: All frame rate decisions are done before importing any media, in the Project Settings.

Secondly: Files get smaller when the bitrate is lower. Want larger files? Set a larger bitrate. Want more quality? Set a lower QP (in H.264/2654/VP9/AV1).

Thirdly: Filesize is bits/s*s. So find the current bitrate (with mediainfo) and set that.
HOWEVER every compression removes data, so you will never get the same quality for the same filesize again. The only question is how much quality are you willing to lose?

Fourthly: To not compress, use Uncompressed
Usually people use an intermediate format like Prores, cineform or DNxHR and do one final render with a quality or file size in mind.

David James wrote: my understanding is super 8 was captured 18 frames per second. If I wanted to change the frame rate,

Topaz is a popular choice to use 'AI' to make up missing frames to get you to 24/25/30 fps. You would do this with your source footage before giving it to resolve.

Resolve added an AI interpolation as well a few years ago as well. If it is better or worse than Topaz, I have no experience. This requires the paid version.


Either way you need to set your timeline FPS to be what you want to deliver before you put anything on the timeline.

Super 8 cameras are able to capture 18 f/s or 24 f/s and many other not standard framerates for slowmotion or timelapse effects. Your original footage might very well have been 24 F/s. Since S8 has no metadata you will have to judge by eye. You can't assume 18 f/s by default.

More importantly, your footage is already digitized and in that process has acquired a new framerate, that of the digital file. Unless the images were scanned one by one (very unlikely) the image was transfered in a process where the S8 projector was running at one speed (hopefully the correct one) and the digital camera was running at another, maybe 25 f/s or maybe 24 f/s. It might perfectly match, it might be slightly off or it might be far off.

Did you have control over the process of digitization? That would be the perfect point to sync the speed. If not, then the next question is, what is the framerate of your mp4 file and what framerate is required for your end result? If, for example, your file already has 25 f/s and that is also what it is supposed to have on delivery, well, then changing framerate on export is not an option. You will have to change your clipspeed within the timeline. Many options for that. For all of the options you will be the judge.

ZRGARDNE wrote:

David James wrote: my understanding is super 8 was captured 18 frames per second. If I wanted to change the frame rate,

Resolve added an AI interpolation as well a few years ago as well. If it is better or worse than Topaz, I have no experience. This requires the paid version.

Optical flow SpeedWarp Faster is best in V20 for this purpose, Optical Flow Standard Faster/Better and Enhanced Faster/Better creates distorted frames but to be expected, SpeedWarp Better handles movement so much worse than SpeedWarp Faster, it's likely another V20 bug, so much extra processing but a worse result.

That is if OP even wants to go down the optical flow route, it will always create some level of artifacting, but in a 18fps to 24fps conversion may go un-noticed with Speedwarp Faster.

Dante Stiller wrote:Super 8 cameras are able to capture 18 f/s or 24 f/s and many other not standard framerates for slowmotion or timelapse effects. Your original footage might very well have been 24 F/s. Since S8 has no metadata you will have to judge by eye. You can't assume 18 f/s by default.

More importantly, your footage is already digitized and in that process has acquired a new framerate, that of the digital file. Unless the images were scanned one by one (very unlikely) the image was transfered in a process where the S8 projector was running at one speed (hopefully the correct one) and the digital camera was running at another, maybe 25 f/s or maybe 24 f/s. It might perfectly match, it might be slightly off or it might be far off.

Did you have control over the process of digitization? That would be the perfect point to sync the speed. If not, then the next question is, what is the framerate of your mp4 file and what framerate is required for your end result? If, for example, your file already has 25 f/s and that is also what it is supposed to have on delivery, well, then changing framerate on export is not an option. You will have to change your clipspeed within the timeline. Many options for that. For all of the options you will be the judge.

I digitized the film, with the Kodak reel’s digitizer. It does scan every frame one by one. There are not a lot of things I can adjust during the capture. I see now when I choose quick render the frame rate in resolve is set at 24fps. Is that resolve reading the file and telling me it’s 24fps?

Mads Johansen wrote:Firstly: All frame rate decisions are done before importing any media, in the Project Settings.

Secondly: Files get smaller when the bitrate is lower. Want larger files? Set a larger bitrate. Want more quality? Set a lower QP (in H.264/2654/VP9/AV1).

Thirdly: Filesize is bits/s*s. So find the current bitrate (with mediainfo) and set that.
HOWEVER every compression removes data, so you will never get the same quality for the same filesize again. The only question is how much quality are you willing to lose?

Fourthly: To not compress, use Uncompressed
Usually people use an intermediate format like Prores, cineform or DNxHR and do one final render with a quality or file size in mind.

I’m not seeing an uncompressed option. I’ll look again. Is the option actually “uncompressed “?

David James wrote:I’m not seeing an uncompressed option. I’ll look again. Is the option actually “uncompressed “?

Yep. (But do note that 3*10*height*width*fps bytes are required per second, so for 2160p at 25 fps it's 3*10*2160*3840*25 = 6220800000 bytes = or just under 6 GB per second.

David James wrote:I digitized the film, with the Kodak reel’s digitizer. It does scan every frame one by one. There are not a lot of things I can adjust during the capture. I see now when I choose quick render the frame rate in resolve is set at 24fps. Is that resolve reading the file and telling me it’s 24fps?

Perhaps. Did Davinci ask to change the frame rate when you imported the file? If so, yes. If not, no.
mediainfo will tell you the container frame rate.

Are there duplicate frames in the timeline? if so, the file is digitized wrong (and we have a more interesting problem). If no, then the original 8mm source is digitized correctly.

David James wrote:I digitized some super 8mm film. Its in MP4 format now. my understanding is super 8 was captured 18 frames per second. If I wanted to change the frame rate, I would do that when I rendered?

You can change fps in DVR. Import the clip, right click and select clip attributes. Now you can change the fps value from 24 to 18 (or any other value you want). If the project frame rate is different from the clip frame rate, Davinci will match the project frame rate using the method chosen in the project settings/interpolation.

Uncompressed is a total waste of space. Use ProRes 422 HQ instead.
If your scan is really frame-by-frame, drop it into a timeline with the needed target frame rate, don't change that when asked. Then use the best algorithm as already mentioned for generation of synthesised frames. Depending on your machine, you may want to switch that back to blend or nearest while working on it and activate it only for final render.

David James wrote:
I digitized the film, with the Kodak reel’s digitizer. It does scan every frame one by one. There are not a lot of things I can adjust during the capture. I see now when I choose quick render the frame rate in resolve is set at 24fps. Is that resolve reading the file and telling me it’s 24fps?

You're not giving enough information, if you did record 1 super8 frame per 1 video frame, and it was encoded at 24fps, it will mean your video will be playing back faster but you can slow it down to 18fps. Is that what you meant by changing frame rate?

By your initial question people thought you meant you were planning to add your 18fps video to a timeline with other footage of 24fps/25/30fps, but maybe you just want to slow down your footage?

CougerJoe wrote:

David James wrote:
I digitized the film, with the Kodak reel’s digitizer. It does scan every frame one by one. There are not a lot of things I can adjust during the capture. I see now when I choose quick render the frame rate in resolve is set at 24fps. Is that resolve reading the file and telling me it’s 24fps?

You're not giving enough information, if you did record 1 super8 frame per 1 video frame, and it was encoded at 24fps, it will mean your video will be playing back faster but you can slow it down to 18fps. Is that what you meant by changing frame rate?

By your initial question people thought you meant you were planning to add your 18fps video to a timeline with other footage of 24fps/25/30fps, but maybe you just want to slow down your footage?

I don’t know stuff and i may be not explaining it correctly. This super 8 film is either 18 or 24 fps. When you watch people move they move kind of fast and something about it seems odd. I thought that if I could make it 30 fps people would look like they are moving at a regular speed.

I used Film Digital projector to transfer my Super 8 films. Used my GH5S recording 24FPS and projector at 24fps adjusting my shutter to get in sync. That was recorded 3940x2160 Vlog .

Brought into a Resolve 24fps project and speed changed to 18fps with Optical flow, Speed Warp faster. That worked fine on my PC with 4070Ti.

I am happy to get all my family films in a form I can watch. I will take time to add music later. Not perfect but actually better than watching the projector with all the setup. I did try single frame recording but felt it would take years to complete !! I had 14, 400ft reels. So returned unit and bought the projector. Buying the projector was cheaper than getting the films converted locally and it means I can repeat ones I would like done again for some reason.

David James wrote:This super 8 film is either 18 or 24 fps. When you watch people move they move kind of fast and something about it seems odd. I thought that if I could make it 30 fps people would look like they are moving at a regular speed.

What does it look like if you step through frame-by-frame? Do you see frames repeating?
If that is the case, you can't fix it without a fresh transfer. But if motion has the wrong speed, you can still slow it down with the regular tools in DR.