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Resolve and Variable Framerate recordings (OBS - NVENC)

PostPosted: Thu Jan 31, 2019 12:41 am
by tolakram
Hello,

hopefully this makes sense. :)

I would like to use Resolve for editing videos meant for YouTube. I capture game footage using OBS Studio and, unfortunately, these encodings are in what I like to call slightly variable framerate. In other words, the framerate is generally locked at, say, 60FPS but will occasionally vary slightly over the course of a recording. The resulting framerate is always 60 but technically audio will go in and out of sync ever so slightly (unnoticeable) due to the fact it is VFR.

Unfortunately Resolve cannot handle this. It tries to keep the audio in sync which makes the audio pop, crack, and skip. Example here: -trimmed- watch?v=afv1khEEiAk Audio breakup starts at 10 seconds. No other video editors I have tried, including Vegas, Premiere, ShotCut, Hitfilm, Lightworks, or OpenShot have this issue. Obviously I would like to use Resolve, otherwise I would not be posting this.

So I think I understand why this happens and I would like to request that Resolve have an option to split the audio from the video in the clip and let me tell it not to even try and sync it up. Maybe the option exists but I've tried just about everything without success.

The only solution I know of is to manually split the audio from the video using any number of utilities but this extra step is a pain and should not be required.

Hopefully this makes some sense. Thanks for listening.

- Mark

Re: Resolve and Variable Framerate recordings (OBS - NVENC)

PostPosted: Thu Jan 31, 2019 6:40 am
by Ole Kristiansen
Or just use programs like Handbrake to convert your footage to constant framerate !

Re: Resolve and Variable Framerate recordings (OBS - NVENC)

PostPosted: Thu Jan 31, 2019 12:04 pm
by tolakram
Ole Kristiansen wrote:Or just use programs like Handbrake to convert your footage to constant framerate !


It's obvious there are numerous ways to 'fix' the issue, that's not the best in my opinion because you're pushing the video through yet another lossy encode. The best way is to split out the audio and include it as a separate track. AVIDemux comes to mind, I think that's what I used a few months ago when I was testing to try and get a good result.

My goal is to quicken the workflow, all these extra steps should not be needed. :) It's easy enough to split out the audio, it seems like Resolve could do this for me.

Re: Resolve and Variable Framerate recordings (OBS - NVENC)

PostPosted: Fri Feb 01, 2019 12:58 am
by Marc Wielage
tolakram wrote:It's obvious there are numerous ways to 'fix' the issue, that's not the best in my opinion because you're pushing the video through yet another lossy encode.

Good or bad, that is the right answer. Variable framerates are very bad for post.

Re: Resolve and Variable Framerate recordings (OBS - NVENC)

PostPosted: Fri Feb 01, 2019 7:50 am
by Tero Ahlfors
tolakram wrote:My goal is to quicken the workflow, all these extra steps should not be needed.


Alright. Record in constant framerate to begin with and there won't be issues.

Re: Resolve and Variable Framerate recordings (OBS - NVENC)

PostPosted: Sat Feb 02, 2019 2:05 pm
by tolakram
So I totally get the responses, makes perfect sense for professional video creators, and there is probably no real incentive to make a free piece of software better suited for YouTube game recordings. I made the post just in case there is a desire by the devs to break into a new market, even though I doubt there's any big incentive to do this.

Using the video card to make game video is a big deal because it doesn't use the processor, this is why the majority of YouTube gamers use it. That's it. :)

Re: Resolve and Variable Framerate recordings (OBS - NVENC)

PostPosted: Sat Feb 02, 2019 4:57 pm
by Jim Simon
tolakram wrote:My goal is to quicken the workflow


Record to a proper editing codec.

https://www.blackmagicdesign.com/produc ... studiomini
https://www.blackmagicdesign.com/produc ... converters

Re: Resolve and Variable Framerate recordings (OBS - NVENC)

PostPosted: Sat Feb 02, 2019 4:58 pm
by Jim Simon
tolakram wrote:I made the post just in case there is a desire by the devs to break into a new market


Adobe went down this path, I believe to the detriment of Premiere Pro for the professional market.

I do hope Resolve never does.

Re: Resolve and Variable Framerate recordings (OBS - NVENC)

PostPosted: Sat Feb 02, 2019 5:52 pm
by Trensharo
Jim Simon wrote:
tolakram wrote:I made the post just in case there is a desire by the devs to break into a new market


Adobe went down this path, I believe to the detriment of Premiere Pro for the professional market.

I do hope Resolve never does.

People believe ridiculous things all the time.

Premiere Pro's trajectory in the Pro market speaks for itself. What they have done, was made it a more viable option for more people; and that's a great thing.

People around here are so jaded. For the love...

Re: Resolve and Variable Framerate recordings (OBS - NVENC)

PostPosted: Sat Feb 02, 2019 6:15 pm
by Greg_E
What if you just unlink the audio from the video?

Or what if you do a 2 step process of putting the video (only) in the timeline, then go back and put the audio (only) in the timeline.

Have you tried any of the game recorders like Avermedia Game Capture Pro or step up to a Datavideo HDR-1 or one of the Black Magic HDMI recorders?

I haven't used my Game Capture Pro in a long time, but I remember that the recordings seemed to work OK in Media Composer because we have used them to create tutorial videos for our students.

Re: Resolve and Variable Framerate recordings (OBS - NVENC)

PostPosted: Sat Feb 02, 2019 7:14 pm
by peterjackson
Can't really see why it would harm if Resolve would handle this better. Many devices can't record at a perfect stable framerate. It's not only screen capture. Though I never had issues with it.

Re: Resolve and Variable Framerate recordings (OBS - NVENC)

PostPosted: Sat Feb 02, 2019 11:03 pm
by tolakram
Greg_E wrote:What if you just unlink the audio from the video?

Or what if you do a 2 step process of putting the video (only) in the timeline, then go back and put the audio (only) in the timeline.

Have you tried any of the game recorders like Avermedia Game Capture Pro or step up to a Datavideo HDR-1 or one of the Black Magic HDMI recorders?

I haven't used my Game Capture Pro in a long time, but I remember that the recordings seemed to work OK in Media Composer because we have used them to create tutorial videos for our students.


Hi Greg,

I did try adding them separately and it didn't work, or I did it wrong. It's worth another try.

Re: Resolve and Variable Framerate recordings (OBS - NVENC)

PostPosted: Sun Feb 03, 2019 3:02 am
by Marc Wielage
peterjackson wrote:Can't really see why it would harm if Resolve would handle this better. Many devices can't record at a perfect stable framerate.

And those other formats are also very bad for post. All of post-production hinges on constant, reliable timecode, and if the frame rate is constantly changing, it's going to cause all kinds of potential sync and timecode problems. This is a bad idea.

Re: Resolve and Variable Framerate recordings (OBS - NVENC)

PostPosted: Sun Feb 03, 2019 3:12 am
by Uli Plank
Imagine you are building a high-rise based on a stable frame of concrete steel, all neatly rectangular and straight. You put in walls, floors, elevators, piping, furniture, and all the rest. Without major impact, it will stand for the next hundred years or more.

Now some crazy architect comes and says: I'd like to build the same, but with tilted angles and not such boring, straight walls, let's make them wavy somehow.

It would never be able to stand without completely revised static calculation! But that's what you are asking from an NLE. If OBS doesn't become a huge market, nobody will build such an NLE. Adobe tried, and see what they got in stability,

Re: Resolve and Variable Framerate recordings (OBS - NVENC)

PostPosted: Sun Feb 03, 2019 9:03 am
by peterjackson
Well, I have no strong feeling about this, but beeing a software architect myself, I think this is not a good analogy.

No one is asking to change that solid architecture. Just someone asked if Resolve could ship with a cutter to split larger parcels in two that don't fit the front door of the perfect building. As the same thing could be archived manually in Resolve with existing functionality, I can't see how this would make the software less stable. This is just asking for a bit of automation.

What is it that technically would be needed? Import the video frame by frame to timeline frames. Then bring in the audio and stretch / retime it to match the clip duration? Is my understanding wrong or is it just that?

If that's it, it's a tiny bit of automation. The same thing could probably hacked together in autohotkey or similar macro tools. I fail to spot any architecture change.

Re: Resolve and Variable Framerate recordings (OBS - NVENC)

PostPosted: Sun Feb 03, 2019 11:52 am
by Uli Plank
Of course, such a hack would be a workaround, and it should be possible with some scripting.

But it doesn't mean that the software is really working with variable frame rates, as some people seem to expect. It will also lead to some asynchronous sound since the series of pictures will be adapted to the stable pattern, but the sound will only be adapted to the full length.

Re: Resolve and Variable Framerate recordings (OBS - NVENC)

PostPosted: Sun Feb 03, 2019 12:03 pm
by peterjackson
Right, it won't be perfect, but neither are any manual hacks currently required. I think the OP is just asking for a workflow improvement, knowing the limitations of the source footage.

The perfect thing would be if Resolve could use optical flow to convert variable framerate footage to whatever constant framerate the timeline is set to. After all this is what happens when you apply a retime curve to a clip. Your clip essentially becomes variable framerate and Resolve is using optical flow to fill every timeline frame slot. That would be amazing and fix any dropped frame as a by product, but a much larger ask.

If you look at it that way, essentially Resolve would have to generate a detailed retime curve for VFR content and the rest would be existing functionality.

If I would be bored enough, I would try to hack a tool together that scans VRF source footage and generates a matching retime curve for Resolve to compensate.

Re: Resolve and Variable Framerate recordings (OBS - NVENC)

PostPosted: Sun Feb 03, 2019 3:18 pm
by Greg_E
Not sure why everyone is getting so bent over this request, it certainly won't ruin Resolve. And with the FREE version, this is no longer strictly a professionals only choice of software. The free version is meant to allow more people to see what it does and hopefully upgrade. It also allows for a much more numerous user base. This user base finds "problems" and and half of them report these problems. This make the software far more robust and feature rich.

I'll have to think about this for a while more, there were some tricks I used with some cheap action cameras many years ago, they also did not record in strictly measured frame rates. The process was annoying, but hardly civilization collapsing event like we seem to be talking about here.

Considering the playback speeds that you can create inside this software, I would have thought that breaking the audio away would have done the job to the point where you could apply a speed change every xx seconds to catch back up. Or that the average would even things out every xx seconds. I bet there is something that can be done if you dig deeply enough. Set markers where audio and video should be synced, then do some kind of motion interpolation (flow like something or other) to resync everywhere the markers don't line up. Probably going to require Fusion or Fairlight to process one or the other parts of the recording. Wish I was more familiar and could just give this info to you, but I'm just starting with Resolve and don't know how to do this yet.

One thing I would suggest is trying a different codec in OBS, it may not be able to keep up with the recording while you are gaming with the codec you are using. A less compressed codec might do better. You may also need to capture at a reduced resolution than screen resolution. Though I think you will eventually end up with an external recorder connected to an HDMI or DisplayPort on our computer.

Re: Resolve and Variable Framerate recordings (OBS - NVENC)

PostPosted: Sun Feb 03, 2019 4:19 pm
by Jim Simon
Trensharo wrote:What [Adobe has] done was made it a more viable option for more people; and that's a great thing.


For Adobe. Not so much for professionals.

As with all things, resources are limited. The resources Adobe spent on developing for the amateur market aren't being spent developing features professionals need.

Their dual-system work flow still needs work. The multicam work flow could use some new features. Their support for professional formats still need work. (CinemaDNG and BRAW, for example.) Premiere Pro finally got the VS curves Resolve has had for a long time. Etc.

Re: Resolve and Variable Framerate recordings (OBS - NVENC)

PostPosted: Sun Feb 03, 2019 4:21 pm
by Jim Simon
peterjackson wrote:Can't really see why it would harm if Resolve would handle this better. Many devices can't record at a perfect stable framerate.


All 'professional' devices can. And the resources BMD spends on including the amateur market are resources they don't spend on features needed by professionals, so it does do harm, I think. Especially when a viable solution already exists. To wit:

https://www.blackmagicdesign.com/produc ... studiomini

https://www.blackmagicdesign.com/produc ... converters

Re: Resolve and Variable Framerate recordings (OBS - NVENC)

PostPosted: Sun Feb 03, 2019 4:33 pm
by Trensharo
Jim Simon wrote:
Trensharo wrote:What [Adobe has] done was made it a more viable option for more people; and that's a great thing.


For Adobe. Not so much for professionals.

As with all things, resources are limited. The resources Adobe spent on developing for the amateur market aren't being spent developing features professionals need.

Their dual-system work flow still needs work. The multicam work flow could use some new features. Their support for professional formats still need work. (CinemaDNG and BRAW, for example.) Premiere Pro finally got the VS curves Resolve has had for a long time. Etc.

I'm sorry, but you're veering from "unreasonable" into "utter stupidity."

What you're doing is writing off those non-professionals as if they don't matter, and then you're making it seem like the changes Adobe has done here has had no positive effect for - literally - millions of people who use their software.

Additionally, Edius Pro, VEGAS Pro, Final Cut Pro and multiple other editors aimed at the "Professional Market" handle this kin of footage perfectly fine.

Professionals aren't special. If those users use, and especially pay, for the software... they had just as much right to have their requests heard and considered. Bullying them on this forum doesn't change that.

Adobe puts a lot of resources into developing for the professional market. What you're saying is nothing more than rumors tainted by bias. The development and uptake trajectory of Premiere Pro in both Amateur and professional markets speaks for itself. Most "amatuers" (and certainly not people using it for the things the OP is using it for) people couldn't even afford that software before it went subscription.

That is why VEGAS Pro/Movie Studio Platinum was such a mainstay in that area of the market (Gamers, YouTubers, etc. - excluding software pirates).

If you have suggestions for improvements, make your own thread. Don't **** on other people's suggestions simply because you think yours have more merit. This is "treadmill" is getting tiresome.

Re: Resolve and Variable Framerate recordings (OBS - NVENC)

PostPosted: Sun Feb 03, 2019 5:35 pm
by Greg_E
BTW, assuming Lightworks does support this vfr video, you might want to look in the archives of their forum... Seems that I recall requesting similar features many years ago. The world also fell apart with this suggestion, but apparently someone found glue to put it back together again.

No one here said "stop everything! we need to fix this right now!".