Video Framerate issues

[btbop]

I'm encoding using VS2022 to H264 mp4 1080P and my resulting frame rates are weird. The resulting video is shorter than the project. Upon checking, the mp4 video plays at 30.100948 fps. It doesn't mater the source, be it images or video, the result is the same. In order to fix this, I need to reprocess through HandBrake at 29.97 fps. Never had this problem with previous versions of VS. What am I missing?

[tletter]

The resulting video is shorter than the project.

Is your source a variable frame rate one, e.g. a smartphone? If so this is a challenge for VS and may need transcoding.

tletter
https://www.youtube.com/user/tletter

[btbop]

No.
The original source is from the GoPro (4K). I strung the individual clips together, split the audio, and processed it into a single 4K mp4 file (muting the audio). The result was a file that played at a different frame rate. The source files play at 29.97FPS, but, the encoded played at 29.89FPS. If I take the original file processed and put it in the main video track, the video and audio are not synched. However, if use the file that was reprocessed at 29.97FPS, it's synched perfectly.

So, now I have the fixed video file synched with the audio file and am laying down additional image overlays and get those images all synched up with the video and audio. Then, I process just the image files into an mp4 video (the main video is hidden). The resulting video frame rate is now at 30.1FPS. If I use that video and place it in an overlay track, it is of course, out of synch. So, I need to now reprocess that video at 29.97FPS to make it work.

So, now I have an mp4 file at 29.97 fps in the main video track, 2 overlays at 29.97fps (mp4) and my audio tracks and I process that into a 1080p mp4 file and it gets processed at 30.1fps and I try it again at 4K and it gets processed at 29.89fps

I've been using VS for years and never have had these issues before. I'm feeling like my first step was wrong. That splitting the audio from video causes an issue that never goes away. Your thoughts?

[btbop]

I think I answered my own question. It appears that I need to initially reprocess the GoPro files into constant framerates before importing them to VS. But, I'm still confused as to why I have issues after converting those. Maybe the split audio tracks are also variable? Weird.

[Ken Berry]

I am a bit surprised by this thread. I have a GoPro 9 Hero Black, and I did not think it could film in variable frame rate. I certainly have never seen a way of choosing or setting that in the camera's settings. Anyway, I just went through the Hero 9 Manual in some detail, and also cannot find any reference to it there. The word 'variable' does not even appear in its 145 pages. Frame rate is of course there, including the information that it can film at up to 240 fps. But all other frame rates mentioned are standard ones such as 24, 25, 29.97/30, 50 and 60 as well as 120 and 240 fps.

What Hero do you have and have you looked for a variable frame rate in the camera's settings. If you can find one, I would be very interested to know where it is hiding.

[btbop]

To be honest, Ken, up until now I didn't know that the Hero had variable frame rates. I've read up on a few forums that it does and people have indicated that they cannot make it fixed. So, as far as I go, I'm not aware of any options that allow you to fix the rate. I have the Hero 9 Black. I have several hours of footage that I can't re-shoot, so, I'm trying to figure out now how to process these efficiently without constantly having to fix the framerate in HB. I'll look into it more, play with the phone interface and see if there are any settings I missed.

[Ken Berry]

OK, so obviously I need to look more closely at my own footage from my Hero 9 Black. But so far it has behaved absolutely correctly, given me to constant frame rate when I look in Properties, and never caused any problems. And VS has been quite touchy about even allowing variable frame rates to play -- though it has, in fact, allowed it from a limited range of sources.

But when, as today, I looked more closely at the Properties of my Hero 9 footage, I only seem to have constant 25 fps or sometimes, when I know I have set it, 50 fps. Mind you, I always use these days H.265/HEVC footage, but I can't imagine that is going to work differently than variable frame rate H.264 AVCHD...

[lata]

I do not own GoPro nor use variable frame rates so is difficult to test never mind suggest a solution.
Adding a variable frame rate to the top timelines may influence the project settings and that could cause conflicts when doing Share.
What happens if you set your project to your desired output, standard 1920 x 1080 x 29.97fps
Then insert the variable video to overlay 1, will rendering still cause the same problems.
Just a thought.

Otherwise I would deselect show messages so that your variable rate video does not update the project settings.

[btbop]

I looked into the GoPro settings and noticed that you're choosing between 30, 60 and 120fps and nothing indicated the frame rate is a variable one. I also took short clips and converted them in VS and had no issues even after splitting the audio. But, here's where I may have gone wrong. After piecing together several video files and splitting the audio, I also laid down a second audio track that I recorded with my phone. The phone audio was simply an mp3 file, but, perhaps, somewhere in that, the conversion was messed up. What's pointing me in this direction is that when I use the same settings as in the video, the audio comes out all garbled. I'll play around some more and see what I can see.

[btbop]

I imported 15 clips from gopro and experimented with a few settings. I used the share to same as first clip settings and the video was not watchable. So, I created a H264 30 FPS 3840x2160 mp4 file and sure enough, the resulting frame rate was skewed and the audio out of sync. Splitting the audio from the video resulted in an audio track that was several minutes shorter than the video track. There is definitely something out of whack here and I don't know how to fix it. I am now converting all the GoPro files using HB and will see if the problem can somehow be corrected.

[btbop]

I have tried everything I can think of. I've processed the GoPro files using Handbrake and imported to VS. I've tried converting the files directly from VS. I've used a number of different settings inside VS to try and create a single video file that plays normally. Every attempt is unsuccessful. When combining each video file onto the VS timeline and processing those videos to a single mp4 file, the resulting file plays at a framerate different from that specified in the settings. I'm using a fixed frame rate at 29.97FPS (each video file) and importing to VS. Then sharing, I've used the following settings:
Same as first video clip - no luck
MPEG-4-AVC 4K - no luck
Custom settings of MPEG-4 3840x2160, 29.97 fps
Frame based
H.264
4800 16 bit stereo AAC
And still no luck. Each processed video comes out at a frame fate of 29.90, or 29.89fps, but never 29.97 fps - wtf?

[lata]

Are you able to share one of your original GoPro video recordings

You would have to upload to a sharing site, then provide us with a share link.

As for variable frame rates, the only reference I found was recording in low light at 60fps would auto reset to 30fps, should that option be set on camera.