PNG image sequence frame rate not matching it's original vid

Hi all,

I'm having difficulty matching the frame rate of a PNG image sequence to the video that was used to create the sequence.

I created the PNG sequence from the video via VLC with the captured frames set to one (i.e. save every frame). Importing the PNG sequence into Davinci as a video and setting it's attributes to the original 25fps before placing it on the timeline, it doesn't match the original video frame rate at all and plays something like twice as fast? Am I missing something in the settings or is VLC not actually saving every frame?

Thanks for any advice.

What is your project framerate?

And is the original video constant fps?

Hi,

the original video is 25fps and variable bitrate (.h264 encoded)

I was asking about the frame rate, not the bit rate.

Is the original video 25i? Maybe VLC is doing some kind of deliterlacing?

Why not just use the original video? Or convert it within Resolve to an image sequence? VLC might not be the best solution for those kind of tasks.

I was asking about the frame rate, not the bit rate.

Hi, sorry I misread your reply. The original video is constant frame rate.

Is the original video 25i? Maybe VLC is doing some kind of deliterlacing?

The original video was deinterlaced (Yadif).

Why not just use the original video? Or convert it within Resolve to an image sequence? VLC might not be the best solution for those kind of tasks.

That was my original intention but I'd graded all the scenes (it's a black and white video) in advance with the levels in GIMP but I wasn't able to match the subtly of the level settings within Davinci. The dark, mid and light in GIMP each have levels +- 0-255 whereas Davinci has the equivalent settings of Lift, Gamma and gain but with +- 20. I thought maybe with fractions of the amounts I'd be able to find a solution to convert the levels but I spent over an hour rendering tests of just the first scene attempting to match my settings but I found it impossible to achieve. The closest I got ended with the black level blown out so I thought I'd resort to a PNG sequence where I can batch convert each scene. I can also then fix any of the major dirt and scratches by hand.

I could try creating the image sequence in Resolve rather than VLC and see how that goes, I should mention also that I am of course writing to the internal NVME SSD when I created the sequence with VLC. I'm mystified at why importing the sequence is twice as fast. Setting the attributes of the sequence when imported back as a video to 11fps (fractions are not possible) it's then close to playing at the rate of the video so it's as if roughly half the frames are dropped.

Any further advice greatly appreciated!

If the DVR does not see the correct fps for the image sequence, change Video Frame Rate manually as needed in the Clip Attributes.

LOL why would you color grade video in a shareware photo editor when you have Hollywood standard video color grading software? If you have a reference still, just bring it into the color page and match your footage to that.

Also, the software is not doubling your frame rate. It can't do that. According to your description, you (or your DP) over cranked it.

If the DVR does not see the correct fps for the image sequence, change Video Frame Rate manually as needed in the Clip Attributes.

Thanks for the reply, as mentioned in the first post I set the clip attributes of the imported PNG sequence to the videos 25fps but the sequence plays back at roughly twice the speed.

LOL why would you color grade video in a shareware photo editor when you have Hollywood standard video color grading software? If you have a reference still, just bring it into the color page and match your footage to that.

Also, the software is not doubling your frame rate. It can't do that. According to your description, you (or your DP) over cranked it.

I don't see any reason to scoff at GIMP it's an excellent and capable photo editor. I had been using Photoshop professionally since it's very early years up until recent years where GIMP is perfectly capable for most tasks. As mentioned in the earlier post I spent over an hour in the colour page with my reference of the first scene attempting to match my GIMP level settings but Davincis color grading didn't appear to have the range to match. I know that Davinci is not doubling my frame rate, that's not what I said, I'm just trying to get to the bottom of why the PNG sequence is not correct at 25fps as per the video it was created from. I set VLC to capture all frames so I expected with a CFR video that it would create a sequence that should match the original frame rate exactly.

What do you see if you check the clip with MediaInfo?

What do you see if you check the clip with MediaInfo?

The original video in MediaInfo confirmed that it's a 25fps non-interlaced cfr file. (I'm away from the computer used for video editing right now).

To narrow this down: can you read the original video in DR? If so, try to export an image sequence (e.g. TIFF) and work with that. What happens on re-import?

To narrow this down: can you read the original video in DR? If so, try to export an image sequence (e.g. TIFF) and work with that. What happens on re-import?

Thanks yea I think that's the next thing to do, I'll be back onto the PC in the morning and will export from Resolve and re-import the sequence and let you know how it went.

If the DVR does not see the correct fps for the image sequence, change Video Frame Rate manually as needed in the Clip Attributes.

Thanks for the reply, as mentioned in the first post I set the clip attributes of the imported PNG sequence to the videos 25fps but the sequence plays back at roughly twice the speed.

If your png sequence is 25 fps and fps in Clip Attributes is 25 fps too, so restart DVR.
This is not first time that DVR plays 2x speeder.

ok, I rendered the PNG stream this morning via fusion, I could see just doing the first 1 minute as an initial test that roughly double the amount of frames had been created compared to the VLC output so it was looking good. Checking it against the original video in the timeline it remained in sync so I went ahead and rendered the entire video and it all was fine except that it was a single frame out, somewhere near the beginning a single frame must be skipped but that's easily resolved manually. I suppose a simple bit of maths should have figured that VLC had not captured all of the frames (@25fps, 1 minute is 60x25 frames = 1500 frames where VLC had only generated 760 frames for the 1 minute test). Rendering time in fusion was just under 4 hours for the 29 minute 1920x1080 video. I can go ahead now and work on the individual frames scene by scene.

There's quite a lot of dust and dirt throughout my video, although I do have the patience to manually remove them by hand, rather than spending months of my life it occured to me this morning that DR has the dirt removal click and clean tool within the color page. It requires the video to be DPX however, can my PNG sequence be imported as DPX or will I need to convert the original video again?

If I do have to convert the original video to DPX will it produce the same exact frame sequence without quality loss? I still want to batch process the frames for each scene within GIMP after they are cleaned so I suppose I will need to create the PNG stream again from DR once the frames have been cleaned.