Choppy Playback with 'Reverse Speed' Clip

[displayname]

I have a problem when I select 'reverse speed' on a clip in the timeline. The subsequent playback becomes very choppy (high % of dropped frames). I have been able to reproduce this problem on two separate computers (both Win 10 machines with Premiere v13.1). This choppy playback does not happen when the clip is played back in 'forward speed', nor if I apply different effects to it like Lumetri colour adjustments. It seems limited to the 'reverse speed' effect, though admittedly I haven't tried too many additional effects yet. But the end result is that the timeline is unwatchable for any clips where I employ this 'reverse speed' effect.

I am at a loss for why this is happening (hence the forum post) and am wondering if I am overlooking something obvious or if this is indeed a bug. Both my machines should be capable of handing this without any issues. I was using an older 'trashcan' Mac Pro from 2013 (with 32GB of RAM) and it didn't exhibit these problems, so I wonder if it is a Windows-specific issue.

Troubleshooting thus far:

- Create proxy clips for all files. No impact.

- Changed playback resolution from full > 1/2 > 1/4 > 1/8. No discernible impact. Maybe slightly better at lower resolutions.

- toggled the Renderer for Mercury Playback between GPU acceleration and software only. No impact.

- Tried different 4k drone clips. Same result.

- Imported 4k clips into a 1080p timeline (and set to frame size). No impact.

- Imported 4k GoPro clips into timeline to see if there was a difference amongst different 4k source devices. Same result.

- Used an older (2013) Mac Pro (trashcan with 32GB of RAM) to play the same timeline and it did not have any problems with dropped frames on the reverse speed clip.

Clip information:

4k .mov files from DJI Mavic 2 Pro

4k .mp4 files from GoPro Hero 6 (for testing)

Computer(s) information:

Workstation:

Custom Build

Asus WS C621E SAGE Motherboard

2x Xeon Silver 4114 @ 2.20 GHz (10 cores each; 20 cores total)

64 GB Ram

Nvidia Quadro P2000

Windows 10 Pro 64-bit (version 1809)

OS drive = Samsung Pro 970 1TB NVMe

Cache drive = same as OS

Media = 8 TB mechanical drive

Laptop:

Dell 5520

Intel i7-7820HQ @ 2.90 GHz

16 GB Ram

Windows 10 Pro 64-bit (version 1809)

3840x2160 resolution

Nvidia Quadro M1200 (discrete)

Intel HD Graphics 630 (built-in)

HDD = 1TB NVMe drive (everything on a single drive)

Premiere Version 13.1 (Magician)

Any thoughts/troubleshooting would be welcome.

- Andrew.

[R Neil Haugen]

I'm really surprised a 4k drone shot ... the LONGEST stuff of the long-GOP format ... would playback sweet on anything.

I would suggest setting your Sequence to Custom, setting a format/codec for "previews" the same as you will be exporting in, and do a render/replace for any reversed media.

Neil

[R Neil Haugen]

A couple comments on your rigs ...

The desktop ... has a ton of cores, but Pr doesn't really use past about 10 or 12, and ... those are very slow cores. Long-GOP media is heavily dependent on a cores/RAM/cache subsystem, and Puget Systems and Safeharbor Computing both recommend as close to 10 cores at 3.8Ghz or faster as possible, with as close to 10GB of fast RAM per core as possible.

What you have are a fair number of slow cores without that much RAM per core, which (I know!) seems ridiculous given the total number of cores and raw RAM available. But in use, it's not an optimal rig.

The laptop ... four cores of medium speed with 4GB of RAM per core. Not ... a fast rig either, for Pr.

So, yea ... I'd use proxies for "regular" 4k drone media and render/replace for reversed clips. And do NOT use H.264 proxies ... use the included Cineform presets as it is an intraframe codec with far better playback.

Neil

[displayname]

Neil - Thanks for taking some time to reply and add your thoughts to the discussion.

A few thoughts on the hardware/rig, and a bit more information.

The 2013-era Mac could play these clips without any issues at full res (and using an external USB 3 drive without proxies), so it suggests to me that there is something else going on. The workstation has twice the RAM, an extra processor, and is 5 years newer than the Mac, so it would seem to me a reasonable expectation that it should perform just as well (and better!) as the Mac all things being equal. I appreciate your comments about cores/speed of the CPU/and RAM per core, but for me the Mac part of the troubleshooting gives me pause in terms drawing a hardware conclusion.

As I noted both machines have no problem playing the native drone 4k clips @ full resolution without dropped frames. They can also play the same 4k clips with some basic lumetri effects applied, but the 'reverse speed' seems to be the Achilles heel.

I can certainly render/replace reversed clips as a workaround but was hoping that I might be overlooking a software setting, or that others have experienced this issue.

Thanks.

Andrew.

[R Neil Haugen]

Andrew,

I've been "around" this and other forums for enough years to have seen some really screwy things about performance. We can go to the 'general' things, such as my comments ... but there'll be some old rig that screams and shouldn't, and a newer one that's a dog ... and shouldn't be.

Talking with computer geeks that build video post rigs, they can go into all sorts of things that affect such things ... among others, both Puget Systems and SafeHarbor computing note that from their extensive testing, there are some CPUs that are vastly better than others for most video post apps ... and cost is not a great predictor. Specs aren't necessarily either. Some of the very expensive i9's struggle to keep up with another specific i9 or even i7 that's half the cost when pushed in Pr, AfterEffects, or Resolve.

And if you're the guy with the incredibly spendy i9, well ... you might not be so pleased about that. But ... it's what happens.

If those machines of yours are playing the drone clips at full res with no dropped frames, even with a titch or two of Lumetri, they are doing very well. Very well indeed.

Many of the guys/gals I work and communicate with are colorists, with massively expensive suites. Their 'confidence monitor' alone is over $10G. They run 6k RED files without issue with tons of effects on them. And transcode nearly every bit of H.264 to a full intraframe codec before adding it onto a timeline. They frequently don't even try to run H.264/4k media "as is" ... period. Maybe if all they've got is a couple clips ... but any more than that, it's t-code time.

Some machines run that stuff amazingly well. Mine doesn't do too bad, and my projects are short, so ... I'll try to get by. If it's gonna be a bigger project, off to creating proxies on ingest. Occasionally, I'll just run a watch-folder preset in MediaEncoder and t-code the lot. Dump the t-codes when done as of course, they've much larger than the original files.

But for me, trying to sort through the various apps & drivers to 'tune' a rig ... well, I'm not the geek for that. I've got my own areas of geek-ness. I know on my setup, Resolve 15.x runs a bit slower to fairly slower than Pr for most any similar item. For some people, it's the other way around. Why? Wish I knew. But as I'm not someone with the knowledge and patience to sort out all the potential issues, I ... just work, as it works.

And wish I could give a better answer. "It depends" ... sucks, as an answer.

Neil

[rodneyb56060189]

4k stuff (with h264 ?) is really hard to edit when adding effects ( even something simple like de-noiser ). I recently did a bunch of that stuff using resolve on a decent editing desktop and finally had to 'optimize' the footage ( resolve's version of proxy files ). Was crashing now and then until I did that.  bummer.

Is there any way you can get by with delivering 1080p ?  I don't think you'd have any problem at all, doing anything you want, with full HD if you shoot that size, without need for transcoding, proxy, etc.

Is a shame the go pro can't just give you pro res or DNxHD or cinemaDNG or something..

[rodneyb56060189]

wow, these things are super expensive !

https://www.amazon.com/Intel-Xeon-Gold-6134/dp/B0745HMDXC

your mobo looks amazing, by the way.

Couldn't find info on what that mobo will take as CPU's … should be in specs you have somewhere maybe.

I don't think it's anything more than cpu speed that's messing you up. It has to decompress the stuff on the fly and that's like really really hard to do ..

looks like render replace or spending big bucks is solution .. or use old trashcan.

[R Neil Haugen]

I'm thinking the CPU speed is an issue also ... that's a really slow CPU for processing frequency, and processing frequency is one of the biggest factors within Pr for H.264 processing. It's a sequential process, and so ... slow cores ... slow process. It's not multi-threaded that much.

Neil

[displayname]

rodneyb56060189​ - The final project will be delivered 1080p. The drone shots are b-roll to an interview that was shot in 1080. With regards to the mobo/cpu - I haven't done a deep dive into the Intel Turbo Boost side of things, but it *seems* like it is something that happens automatically if your motherboard and CPU support it. In my case the motherboard does support it and I think that it is automatically enabled in BIOS (but need to double check). The CPU (my 4114 Silver) should then go up 3.0 GHz and drop the number of cores that are being used (Intel® Xeon® Silver 4114 Processor (13.75M Cache, 2.20 GHz) Product Specifications ) under load. That is my understanding. My CPU/GPUs are barely taxed when working with this particular timeline so it is unclear to me if this happens or not.

Christian.Z - This seems to be (more or less) limited to the reverse speed effect. I did some testing yesterday at 200% forward speed and it eventually played smoothly using the proxy files. Not the case with reverse.

Ann Bens​ - I haven't rendered it yet, no. Is your thought here to see if the render contains dropped frames of if it exports without issue?

R Neil Haugen​ - If I am using proxies that are significantly smaller (both pixel dimensions and file size) shouldn't that ordinarily negate any issues related to 4k footage from a device like a drone? Or put another way - if I am seeing the same behaviour regardless of whether I use the original file or a tiny proxy, is that not an indication that something else is afoot?

Thanks all for jumping in with thoughts/explanations. I think one of the reasons that I am perseverating on the CPU side of things (as in I am not totally convinced that it is the CPU at fault here) is that it doesn't have any other problems when I am using Premiere - it hums happily along. Different effects, faster forward speed, etc. It seems to be limited to this one particular thing 'Reverse Speed'.

On the road for the next week, so apologies if I am radio silent. Thanks @all for their thoughts.

- Andrew.

[Ann Bens]

In Premiere rendering means making preview files.

If you render the clip the choppy playback should disappear.

[rodneyb56060189]

I searched a lot for cpu with that socket … Andrew has silver … 10 core, etc.   I saw the gold one ( just has more cores), very expensive, had some literature at some site about INTEL TURBO BOOST which gets it up to around 3.4 ghz ….

so I'm wondering if Andrew has intel turbo boost on his machine, and maybe he can crank those 2 cpu's up to around 2.8 ghz and I bet that would solve the problem.

I just worry about heat when overcranking stuff, but I guess if it's an intel chip and an intel turbo boost, they must have tested that out already...

[rodneyb56060189]

This might help re: what is going on with trashcan using H264, power consumption, cpu and gpu speeds, temps, etc.

Power Consumption & Noise - The Mac Pro Review (Late 2013)

anyway, good luck Andrew. Nice mobo and storage etc. !!!!

[Ann Bens]

Did you render the timeline?

[Christian.Z]

This is normal. You will also feel dropped frames when speeding up. Consider rendering the timeline.

[rodneyb56060189]

Thanks for fantastic info and update re: that one effect ( reverse ). I would imagine it would be automatic ( dropping cores and upping Mhz as per need , like the trash can ) but who knows. It is an amazingly fast and cool mobo and stuff, and it's a shame things are not working perfectly yet.

Thanks again, and please post here when you solve the problem, cause I am fascinated by this difficulty.

Good luck

[displayname]

rodneyb56060189​ - *If* I solve this problem. We'll see. In spite of hoping/thinking there may be an underlying issue and paired solution it may be a situation as R Neil Haugen​ describes where there is no rhyme nor reason for why a particular setup behaves one way or another. We'll see! (or won't).

- Andrew.

[usman5F98]

Im having the same problem.
Tried everything from lower res to proxies to rendering.
Only thing that worked was 'Render and Replace' while playing with the frame rate.
Hope it helps.

[rajeevm25632244]

Thank you so much. That is the only thing that helped!

[Warren Heaton]

I know this is a 2019 post, but have a very important thing to address:  Convert to a CODEC that is good for editing and this becomes a non-issue.  GoPro provides free software to convert to ProRes specifically to convert GoPro source footage to a good editing format.  Of course, the conversion can be done in Premiere Pro or with Media Encoder.  It doesn't have to be ProRes, any of the Smart Rendering CODECs will do.  There's often the reaction of, "but I should not have to do that"; however, if your recording device doesn't support recording a good CODEC for editing directly, that's exactly what we video editors (or more specifically, our assistant editor) need to do.