4 Black frames at the beginning of each imported video clip

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Taabbm

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4 Black frames at the beginning of each imported video clip

PostThu Jun 01, 2023 9:14 pm

I imported several videos from my Samsung phone in H.264 MP4 format. On my Mac QuickTime shows the first four frames as black with audio playing in the background. The same thing happens when I import the files into resolve. I have the latest non-beta version of resolve 18. When I play the files in VLC, they play fine with no black frames, when I use handbrake to convert the files to MKV they work fine with no black frames. The clips are one frame longer in MKV than they are in the original MP4.

This is driving me crazy. Does anyone know why this is happening and how I can fix it without having to convert all of my files to MKV?
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Marc Wielage

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Re: 4 Black frames at the beginning of each imported video c

PostSat Jun 03, 2023 3:25 am

Taabbm wrote:I imported several videos from my Samsung phone in H.264 MP4 format.

H.264 smartphone video files are often variable framerate, and they wind up being very bad for post. My advice would be to convert them to a static framerate (like 30fps or 25fps, whatever the native phone rate was supposed to be), and also transcode them to a simpler codec like DNxHR or ProRes. Do that, and I bet they'll export just fine.
marc wielage, csi • VP/color & workflow • chroma | hollywood
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CougerJoe

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Re: 4 Black frames at the beginning of each imported video c

PostSat Jun 03, 2023 4:30 am

Can you take a short sample video, verify it shows the 4 black frames at beginning then upload it to a file sharing site?

Others can verify they also get 4 black frames
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Taabbm

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Re: 4 Black frames at the beginning of each imported video c

PostSat Jun 03, 2023 5:41 am

Thanks for the replies and suggestions. I am a somewhat experienced beginner, so your expertise is greatly appreciated.

Marc - What app would you recommend to transcode the file to Prores? Can I do that with Resolve or is there a better choice?

CougarJoe - Here is a OneDrive link to one of the files.
https://1drv.ms/v/s!AmL5eOGSoJnciN4eyxD ... w?e=jgdh3n
If you play it on OneDrive it works fine. If you download it and try to play it with QuickTime you will see the black frames.

Thanks again.
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CougerJoe

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Re: 4 Black frames at the beginning of each imported video c

PostSat Jun 03, 2023 9:16 am

Yes, I have 6 black frames at beginning. In Premiere there are no black frames.
I"m using 18.,5 beta 3

It is variable frame rate as expected. All phones are, but it's not the sort of variability that should create this problem

Frame rate mode : Variable
Frame rate : 24.000 FPS
Minimum frame rate : 24.000 FPS
Maximum frame rate : 24.006 FPS
FrameRate_Real : 24.000 FPS
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Uli Plank

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Re: 4 Black frames at the beginning of each imported video c

PostSat Jun 03, 2023 10:10 am

No idea why, but I also get 6 black frames. Using Shutter Encoder (Donationware) I can convert it to ProRes plus conform to 24 fps, and it plays absolutely fine.
No, an iGPU is not enough, and you can't use HEVC 10 bit 4:2:2 in the free version.

Studio 18.6.5, MacOS 13.6.5
MacBook M1 Pro, 16 GPU cores, 32 GB RAM and iPhone 15 Pro
Speed Editor, UltraStudio Monitor 3G, iMac 2017, eGPU
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CougerJoe

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Re: 4 Black frames at the beginning of each imported video c

PostSat Jun 03, 2023 10:24 am

I tried turning GPU decoder off, still have 6 black frames
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Uli Plank

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Re: 4 Black frames at the beginning of each imported video c

PostSat Jun 03, 2023 11:32 am

Sorry, but it's. phone.
In my experience they generate a lot of issues and the best approach is transcoding with conform.
No, an iGPU is not enough, and you can't use HEVC 10 bit 4:2:2 in the free version.

Studio 18.6.5, MacOS 13.6.5
MacBook M1 Pro, 16 GPU cores, 32 GB RAM and iPhone 15 Pro
Speed Editor, UltraStudio Monitor 3G, iMac 2017, eGPU
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CougerJoe

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Re: 4 Black frames at the beginning of each imported video c

PostSat Jun 03, 2023 12:26 pm

Uli Plank wrote:Sorry, but it's. phone.
In my experience they generate a lot of issues and the best approach is transcoding with conform.


It's a bit like downloading VP9 and AV1 video from Youtube because higher than 1080P only comes in those formats. You could transcode them or you have a great VIdeo editor like Resolve that allows you play VP9 and AV1 video. Same should apply to Phone videos. Premiere Pro, Capcut, even built in Windows Video editor plays without black frames.

Is it a bug?
Is it a limitation that applies to it's ability to read variable frame video even if it only drifts by .006 frames from it's real frame rate?

This is something that should be fixed due to how popular Phone videos are today
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Taabbm

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Re: 4 Black frames at the beginning of each imported video c

PostSat Jun 03, 2023 10:15 pm

Thanks, I really appreciate the help.

Uli - I downloaded Shutter Encoder and the problem seems to be fixed as long as I transcode the file with a constant FPS. This looks like a great program so I donated. I think it will come in very handy. Thanks again. I think you are right that the issue is somehow caused by the encoding used by my S22 Ultra. The strange thing is that many programs play it with no problem, but a few, especially those associated with Apple, do not.

Conspiracy Theory - Apple intentionally does not support whatever Samsung is doing with the encoding. Probably not, but knowing Apple this is unfortunately plausible.

CougarJoe - I am nowhere near a professional video editor, but it sure seems that a high-end program like Resolve should be able to play these files correctly. Especially considering all the other programs that do play them correctly.

Thanks, everyone for the help. For now, I will transcode the files with a constant fps until I find a better solution or the problem gets fixed.
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Marc Wielage

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Re: 4 Black frames at the beginning of each imported video c

PostSat Jun 03, 2023 10:32 pm

Uli Plank wrote:No idea why, but I also get 6 black frames. Using Shutter Encoder (Donationware) I can convert it to ProRes plus conform to 24 fps, and it plays absolutely fine.

Shutter Encoder is a widely-recommended solution that can transcode pretty well.

CougerJoe wrote:This is something that should be fixed due to how popular Phone videos are today

We just tell people: avoid using smartphone cameras, because they're very bad as cameras. If you have to use them -- as I said before -- transcode them before using them for post.
marc wielage, csi • VP/color & workflow • chroma | hollywood

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