Delay/Lag when moving around timeline

aux137 Posts: 15 Just Starting Out*

Let me start by saying I know almost nothing about computers, so technical questions will likely get a blank look from me until you explain it like I'm 5.

But with that in mind, I've had almost no problems using Hitfilm for some time now, but have recently hit a snag when trying to edit. Clicking on any point in the timeline leads to a good 5-10 second delay before the...white line thingy...catches up and the viewer image changes. Scrubbing through the timeline is impossible, and forget about trying to play anything even at a low-resolution.

Come to think of it, the Trimmer view won't play back either for the same reason. It gets hung up on one frame, eventually fights its way to another, later frame, and then struggles to leap on down the line. It's like me trying to walk by a buffet.

I'd seen a similar issue in the past when I had too many programs running in the background, like video capture software or Photoshop, so maybe it's something to do with "RAM," but nothing else is running now and I don't know how to check what might be slowing me down so badly.



  • tddavis
    tddavis Posts: 5,256 Expert

    @aux137 Have you maybe changed the preview viewer's playback settings under the OPTIONS button at the top right?  If you have increased them recently that could be the source of the laggy performance.  Also, if this project has some intensive effects like particles, or motion blur both of which are known RAM hogs in preview.  Okay, disregard the first suggestion, I just glanced up and saw you have tried low-resolution playback.  Sorry, I can't be more helpful.

  • aux137
    aux137 Posts: 15 Just Starting Out*

     The only thing I can add is that I don't have any effects other than cross-dissolves/fades for the transitions and a couple composite shots in the opening title.  

    I *do* have a lot of files in the media folder. More than I would actually use since I batch dump into Hitfilm and then select the best take when I can analyze them better. I wonder if that could be impacting things.

  • Triem23
    Triem23 Posts: 20,415 Power User
    edited January 2019

    What is the CPU, GPU, OS, Ram amd storage of your computer? What is the source of your video (screen capture, phone/tablet, GoPro, DSLR/Mirrorless, camcorder?) What file format is the video? Mp4  (probably), or MOV (probably still using mp4). 

    There are a lot of factors that can affect Hitfilm performance. For example if you don't have a dedicated GPU (just one integrated into your CPU) then you have a slow machine. Mp4 video takes a lot of computer resources to decode. Something like Cineform will perform much more smoothly (but with much larger files). How long are your source videos? It doesn't sound like you are using three hour game captures, but long videos (over 15 min in a single clip) can affect performance. Things like dissolves - if you happen to be dissolving between two sections of the same clip that can cause slowdown - especially with mp4!

    I wouldn't think lots of clip in the media bin would slow things (thoughts @NormanPCN?)  but deleting media you know you won't use can't hurt.

    This video discusses how video works (including explaining why mp4 is slow) along with several ways to transcode to faster formats. At 17:00 it discusses how to find your system specs (CPU, GPU, OS, RAM - to get drive capacity right-click on a drive and select "Properties.")

    Hopefully the video's explanations work for you. :) 

  • NormanPCN
    NormanPCN Posts: 4,385 Expert

    Lots of media in the bin should have no issue. The timeline at the instant of playback is what matters. e.g. It does not matter what the timeline was doing a minute previous or a minute later. All that matters is right now at the timeline playback position.

    From the description is sounds like high overhead video  like AVC/H.264 video (commonly in MP4 files) and a computer not fast enough for Hitfilm to handle that media. The transcode seems like the solution to the problem.

  • aux137
    aux137 Posts: 15 Just Starting Out*

    That video was very helpful, thanks for sharing it.  It turns out my source video is AVI/MJPG which he describes as being good formats to edit from. Except for some PNGs, they're all captured from videogames using PlayClaw. None of these AVIs are longer than 4 minutes/1.6GB.

    The rest of my computer stats are:

    CPU: Intel Core i7-4720HQ @ 2.60 GHz
    Graphics: Intel HD Graphics 4600 & NVIDIA GeForce GTX 960M
    OS: 64-bit Windows
    RAM: 16 GB

    For storage, my main drive (that I'm thinking Hitfilm runs from) is 27.6GB free (of 236GB), while the video files are stored on a 2nd, higher capacity drive with 314GB free (of 913GB). Like I said, this system has been running smoothly for a couple years. I just don't know where to look on my machine if there's something that's changed that would affect playback like this.

    Thanks for all your help, guys. It's really appreciated.

  • NormanPCN
    NormanPCN Posts: 4,385 Expert

    "It turns out my source video is AVI/MJPG which he describes as being good formats to edit from."

    Yes and No. While motion jpeg does have a lower decode overhead; Video for Windows does not perform all that well in Hitfilm. Hitfilm must go through Video for Windows to decode the M-JPEG AVI format.

    The two edit formats that perform best in Hitfilm are Cineform and Prores. They are both implemented natively. For a long time DNxHD/HR in a MOV container was recommended but this requires Quicktime and it does not perform as well have the native formats.

    The 2.6Ghz clock rate of your CPU is kinda low for a high overhead format like AVC/H.264 so it is not surprising you got timeline lag. Fast decode AVC might work.

  • aux137
    aux137 Posts: 15 Just Starting Out*

    An update, I took my footage and used Hitfilm itself to export it as Cineform (the RGB version in case it matters) and found no change in performance. A few clips in and the timeline becomes unusable for the lag.

    The important thing to me is that it used to work just fine for this same use. I've been stitching gameplay footage together for years. It just suddenly stopped being effective. I guess my question is, what element of my computer is *supposed* to be working here, and how can I check to see what happened to that element that it's suddenly not up to snuff? Maybe I installed something that's bogging it down? Maybe I've something running in the background that's using up computer power. Like I said, I know nothing about computers.

    Thanks again for all your time. I appreciate the help.


  • NormanPCN
    NormanPCN Posts: 4,385 Expert

    "...I took my footage and used Hitfilm itself to export it as Cineform (the RGB version in case it matters) and found no change in performance. "

    It might matter depending on the export settings you used. The RGB Cineform variant has a higher bitrate and the Hitfilm Cineform RGB preset also outputs the alpha channel which increases the bitrate and the Hitfilm Cineform RGB preset uses the Filmscan1 quality setting which gives very high birates on top of the other two. Alpha is a complete waste for source transcoding. Filmscan is also a waste. The YUV variant is most appropriate for source media transcodes at Medium or High quality setting.

    You might have created file(s) with bitrate requirements beyond what your hard disc can reliably handle.

  • aux137
    aux137 Posts: 15 Just Starting Out*

    Thanks again, Norman.

    I'll give the other Cineform format a shot. In the meantime, would you mind sharing any ideas of why it would run smoothly a couple months ago but now be suddenly unusable due to the lag? Any guesses what could impact my CPU performance so abruptly?

  • Triem23
    Triem23 Posts: 20,415 Power User

    Is your video drive a hard drive or SSD? If it's a hard drive you probably need to defrag it. 

    Defrag? Yes, the hard drive is a physical platter. To sarcastically describe the platter its a disc of plastic coated in rust. The rust is aligned on the platter in one orientation for a 0 bit a different way for a 1 bit. (@NormanPCN should have chuckled at the joke, then been horrified at the oversimplified explanation). 

    Point is data is written to different physical locations on the platter.

    For the moment, lets pretend that "-" is empty space, "*" is any file and "V" is an example video file.

    Empty drive: - - - - - - - - 

    Add data to drive: ***-----

    Add more data to drive: *******-

    Delete first files: - - - ****-

    And this is where we start running into issues. Free space is no longer "contiguous," or "all together." Maybe we now add our video file and we get: VVV****V

    So our video file is now split to two locations. When reading this file the drive accesses a physical location then has to actually move to another location to read the rest of the file. This is slowdown. 

    Eventuality your drive could look like: - V**V-*V

    And that's a mess. 

    Defragging (DEFRAGMENTING) consolidates files and free space to turn the drive to: ***VVV--.

    Since the CPU is responsible for disc read/write and file encode/decode anything that slows down your drive also slows Hitfilm's utilization of the CPU.

    Note you're ASSUMING CPU slowdown here. Disc fragmentation could be a part of it. As Norman noted your Cineform files might be at too high of a bitrate for your drive to pass real-time. Certain Windows updates might or might not affect system resources. Certain Nvidia driver updates may be causing issues.- it seems once a year, or so, an Nvidia driver causes an issue the Hitfilm devs have to patch (same with OS updates) Certain INTEL updates might affect resources. In fact an Intel security update from early 2018 DID slow down all affected CPUs by as much as 10% so yes, it's possible your computer is slower today than at this time last year. But, in the absence of system performance report from today compared with one from six months ago it's tough to determine what's causing the slowdown. We'll keep trying everything we can think of, but there's a lot of variables.... Case in point, it took us a week to even ask about possible drive fragmentation! 

    So, assuming your videos are on a hard drive you should defrag regularly... Every month or two at least. That should help. How much will depend on how fragmented the drive is.

  • aux137
    aux137 Posts: 15 Just Starting Out*

     Thanks, Triem. My C: drive is SSD, but the data drive that I'm storing all my video files on is regular ol' rusty platter. The computer says it optimizes weekly and shows the D: at 0% fragmentation, but I'll give it a try anyways and see what happens.

    Thanks again.

  • aux137
    aux137 Posts: 15 Just Starting Out*

    So far the YUV Cineform seems to have eased my troubles. Still not sure why this would suddenly be an issue, but I'm content with the work-around. 

    Thanks again for everybody's help.

This discussion has been closed.