SLOW Effects Render and Export - OBS 2K Screen Capture With Effects

[Photo Taco Podcast]

I am trying to create some video training.  I am using OBS to capture my screen to create the training on how to use some software.  I am recording in OBS to Quicktime .mov files.  The pixel dimensons of the screen being recorded is 2560x1600.

I import a 30 minute .mov file into a new sequence and it renders out to a .mp4 just fine, takes under 30 minutes.  If I add a single effect to the clip (magnify or brightness/contrast are the two I have used) render effects in/out, render in/out, and export to mp4 all take so much time there is no way I can wait for them to complete.

Here are the details on the setups I have tried

• Premiere Pro 2020 14.0.4 Build 18
• macOS Catalina 10.15.3
• 2018 MacBook Pro 15", 2.2 GHz 6-Core Intel Core i7, 16GB 2400 MHz DDR4, Radeon Pro 555X 4GB
• Source file: 617.6MB 2560x1600 30:50 (minutes:seconds) QuickTime .mov that plays great in QuickTime and previews OK in the timeline at 1/4 quality.  Located on internal APFS formatted SSD.
• Export:
  • Format: H.264
  • Width: 2560 (same as source)
  • Height 1600 (same as source)
  • Frame Rate 29.97 (same as source),
  • Performance: Hardware
  • Profile: High
  • Level: 5.1
  • Bitrate Encoding: VBR, 1pass

Export ran for8+ hours.  Estimated time remaining at that point was 52 hours more, 19% was done.

[Kevin-Monahan]

s814jdh,

Sorry for the poor performance with this particular workflow. There are several issues that can be addressed with some potential for performance improvments.

• Format + Sequence Size: The first issue is that you are working with a large H.264 file in a overly large sequence. 
  • H.264 is a codec that is perfect for screen captures, but does not do well as an editing or rendering codec.
  • You'd be better served with a smaller sequence, say HDTV sized, so you can edit more nimbly and render & export faster and easier.
• Workflow: A bit more care in your workflow might save you hours of time. It takes a lot of hard drive space up front, but I like to use smart rendering when I am advising those that have these kinds of issues. Tell you about that in a minute. Another workflow win is to create add edits (splices from the razor tool or shortcut) around any effects you are creating. That way, you are not disturbing the render files you already created, saving time and drive space.
• Hardware:
  • Ensure that your GPU is enabled in Project Settings > General. Your computer should use Metal protocol. 
  • Ensure that the SSD you are exporting to is separate from the drive containing macOS.

There are a couple of ways to approach a smart rendering workflow with screen capture. What I'd recommend to you are a few steps that are simple, yet effective.

1. In Sequence > Sequence Settings, set the Editing Mode to Custom. Scroll to the top of the list to find it.
2. In the section for changing your codec for rendering previews, set it to QuickTime > ProRes LT.
3. Your preview files will be in ProRes LT format. This takes up room, but you can delete these files upon completing the project. As you work, render the timeline every time you walk away from the machine, the goal being a fully rendered timeline of ProRes LT preview files that is ready to export. You should have a green bar across your entire sequence.
4. When exporting, choose to Match Sequence Settings and check the "Using Previews" box (important). The export process is very, very fast since you are only copying the files, harnassing your previously created render files. A ProRes master is the result. If the export is not lightning fast, something is amiss. I find this fast export an ingenius discovery. Try it.
5. With this ProRes master, feel free to upload that to YouTube, or encode an H.264 files from the master. It will be much faster than exporting a H.264 file from scratch.

Let me know if you have any questions about this workflow.

Thanks!
Kevin

[Photo Taco Podcast]

Adobe support is having me use Handbrake to transcode the QuickTime .mov file to .mp4 using the H.264 codec.  So, contradictory advice here.  We also tried Premiere Pro 2019, didn't change anything.  In/out render of 15 seconds took 20 minutes to complete.

[Photo Taco Podcast]

But I don't think my source is an H.264 encoded format.  Is it? Is QuickTime .mov H.264 encoded?

[Photo Taco Podcast]

I tried as you suggested.  I cut the clip of the QuickTime .mov down to only have the first effect applied to it (opacity).  52 seconds in/out.  Changed the rendering options as outlined to QuickTime ProRes LT.  43 minutes to render 52 seconds, and it wasn't making progress.

[Photo Taco Podcast]

Also to note, while attempting to render (effects in/out, render in/out, export) the CPU gets pegged at 100% and the GPU doesn nearly nothing.

[Photo Taco Podcast]

Should I transcode the entire QuickTime .mov source file to ProRes LT?

[R Neil Haugen]

Yes. Do that before sitting down to edit. And you can even do it overnight in a batch, of course. And easy way is to set up a "watch" folder in MediaEncoder, with the output transcode/export settings you want and to a set folder.

Thereafter ... when you drop a clip or bunch of clips in that watched folder, Me will open and start processing them "in the background" if you're working in Pr, but ... I do that when going to lunch or home.

When you get back, you go to the export folder, and move the files to where you want them for use in the project. You can of course delete them after the project is finished, because you can re-create them any time you need to.

Neil

[Photo Taco Podcast]

Transcoded the OBS QuickTime file to QuickTime Apple ProRes 422 LT using Media Encoder.  Same result.  The source location of the file doesn't matter.  Tried external SSD and internal SSD.  The process is CPU bound.  GPU is used about 25% spikes here and there (sure wish I would see Premiere use that GPU) even though I have it configured to use GPU (metal).  Disk I/O is boring with some reads happening at the first and then very little after that.  100% CPU. All cores fully consumed and taking forever to make this work.

At the advice of a friend who is more familiar with OBS and has seen issues like this in the past, I transcoded the video to ProRes LT but this time I did NOT transcode the audio with it.  He uses FCPX and has had similar issues due to the audio that OBS produces in the files.  That also changed nothing.  15 minutes to render 15 second in/out.

[R Neil Haugen]

I would be very surprised if that media wasn't H.264/long-GOP.

Also ... there is a chance that it is VFR, variable frame-rate, as many screen capture and phone media apps use that type of recording. VFR means the app/device has a "suggested equivalent" frame-per-second or FPS setting, but ... then decides whether it really needs to use that many frames, or if perhaps it could get by with a bit fewer because it doesn't seem to have too many moving pixels at this moment.

So ... while OBS says the framerate is say 30, when you look at the media in something like MediaInfo you may see it listed as VFR, with frame-rates varying from 27.3 to 30.8 fps within the file.

The audio however is recorded on a constant basis ... so the video is varying frames per second, the audio isn't, and it's darn hard on an NLE to puzzle out.

This would be why the Help people suggested re-encoding in HandBrake ... to get the media into CFR, constant frame rate. Where you would need to go to the Video tab and both check the CFR box, and set a specific number frame-rate in the frame-rate selection box.

Neil

[Photo Taco Podcast]

Adobe Support had me transcode using Handbrake.  They had me go to an H.264 encoding, which I asked them about given the advice provided thus far.  That did nothing.  I used Media Encoder to transcode to QuickTime ProRes LT, which also did nothing to change the horribly slow render times.  What transcode settings should I use in Handbrake?

[R Neil Haugen]

Listed in my reply above ... check CFR box. Set a number like "29.97" or some specific number option closest to the original media's 'aim' point. Set the compression options to "near placebo" to keep from re-compressing.

Then t-code that in Me to ProRes LT ... and use that in Premiere.

That will get the best performance possible out of the computer you're using. That rig isn't going to be a hot performer, but ... this would be better. Then use Kevin's comments on the editing process ... have it render "previews" in the same ProRes format you'll export to when you take a break, lunch, answer the phone, go sleep, whatever.

Then when exporting the final project, the export will be faster.

Neil

[Photo Taco Podcast]

Here are the Handbrake transcoding settings I tried: