Twitch converting CFR into VFR. Can I prevent it?

[Mongon]

TLDR: Twitch takes my neat little CFR stream and VIOLATES it with VFR, making my life as a youtuber an asynchronous headache. Is there any way to stop Twitch from changing my stream from CFR to VFR?

Note: I know about HandBrake. Aside from prevention, I am also looking for solutions that does not involve converting and increasing file size.

 

 

I've been researching ways to make my process of Twitch streaming -> YT content faster and take up less storage space. My current workflow is: stream, make stream highlights, download highlights from the Twitch website, and import them into Adobe Premiere Pro. My current problem is that the downloaded video (mp4) from Twitch is in VFR and the A/V ends up out of sync when imported into Premiere. 

 

According to the internet, there are many ways to fix a VFR video. The only one that has worked for me is converting the video back into CFR with Handbrake. Even with HandBrake, the audio is still slightly offset but has the same offset throughout the video (instead of an increasing offset farther into the video). This allows me to shift the audio until the A/V lines up enough but not perfectly. Other methods involve simply renaming the file to .mov or .m4v or .dif. These have either done nothing or are incompatible with Premiere.

 

Here are some Premiere settings I have checked and tested without success: Preserve Audio Sync is on by default. Changing the sequence, timecode, and interpret footage settings doesn't help.

 

I recently improved my OBS settings enough that I almost never miss frames. Recently, I streamed Spelunky 2, a very easy game to run. My OBS output a constant 60 fps and missed less than 100 frames over the 2 hours I streamed (I never skipped or dropped frames).

The highlights from that stream (9 min long) also ended up out of sync. Since it can't be my OBS's fault, the problem has to come from Twitch. 

What ticks me off the most is the Media Info of this video:

 

Frame rate mode                          : Variable
Frame rate                               : 59.775 FPS
Minimum frame rate                       : 0.936 FPS
Maximum frame rate                       : 62.500 FPS
Original frame rate                      : 60.000 FPS

 

Spoiler

Look how they massacred my boy.

Since the "original frame rate" was 60 fps, I can infer that the video (untouched by Twitch) was indeed CFR. Strangely, this is the first time I've seen "original frame rate" in my mp4 files. (Also, I have never seen a minimum frame rate that bad. It's usually just a few frames below the maximum)

 

In the end, I could just use HandBrake or record the whole stream on my hard drive. But after trying for so long, I REALLY want to have my cake and eat it too. 

Is there anything I can do to have my way and give Twitch the middle finger or should I surrender to the HandBrake meta?

[Electronics Wizardy]

Why use the twitch file for youtube? Id just have obs save the file, and then edit that for yourtube. Better quality, and should be faster.

[Mongon]

1 hour ago, Electronics Wizardy said:

Why use the twitch file for youtube? Id just have obs save the file, and then edit that for yourtube. Better quality, and should be faster.

I'm trying to save space by not recording.

[Electronics Wizardy]

2 minutes ago, Mongon said:

I'm trying to save space by not recording.

How big are the files? You can just delete them when your done, and should only be a few gigs a hour. HDDs are pretty cheap that could store hundreds of hours of video.

[Mongon]

1 minute ago, Electronics Wizardy said:

How big are the files? You can just delete them when your done, and should only be a few gigs a hour. HDDs are pretty cheap that could store hundreds of hours of video.

I stream on my pc and edit on my laptop. I don't have much money so I use free google drive as my "cloud storage" and use it for saving video material like pngs.

Now that I think about it, I could buy a large external hard drive and transfer all my recordings into there.

Even so, I still would like to know if I can do something about the Twitch highlights even if the answer is "no, what you are asking for is impossible." 

[Mongon]

On 6/24/2021 at 9:58 PM, Electronics Wizardy said:

How big are the files? You can just delete them when your done, and should only be a few gigs a hour. HDDs are pretty cheap that could store hundreds of hours of video.

So, I ended up recording a 2.5 hour long stream at 1080p 60 fps at 15 CRF and it ended up being 105 gigs. That's about 42 gigs per hour.  Would increasing the CRF help enough?

[Electronics Wizardy]

12 minutes ago, Mongon said:

So, I ended up recording a 2.5 hour long stream at 1080p 60 fps at 15 CRF and it ended up being 105 gigs. That's about 42 gigs per hour.  Would increasing the CRF help enough?

15 crf is pretty high quality, and seems to be averaging at about 100mbit. Id try a crf of 20 and see what the quality is like.