Timeline viewer lags when stacking mutliple clips on top of each with seperate tracks

liquidlegsliquidlegs Website User Posts: 8

 The PC specs are as follows:

OS: Windows 8.1
CPU:Intel I7-4770 3.40GHz
GPU GTX 1060
RAM: 32 GB

OK, so i have 2 video tracks, and 2 clips. The 2 clips have been stacked on top of each other and are sitting on 2 different video tracks (one clip per track). So when i press the play button the video is the viewer window will lag so badly that there's no way for me to see what is going on. The viewer will only stop lagging until the timeline has gone past the part of the video where the 2 clips overlap.

This issue occurs 100% of the time and it doesn't seem to matter how it is reproduced, it will always lag. Sadly there no error messages or crashes, it happens repeatedly, and its not exactly something i expect to happen.
By the way I am new to Hitfilm so I apologize if this question has been asked on the forums before, but i haven't found any threads that have described the same issue Ive had.

if it helps that little bit more the footage I'm using is something Ive recorded from a game. I followed one of the Hitfilm tutorials to convert the footage to use CFR which improved how much i can see in the timeline viewer but not enough not solve the problem.

Here's how you could do it for yourself step by step

1: Start a new project
2: Import your videos
3: Insert a video track
4 Drag your video into the timeline and place it on the top video track
5 Grab the same video or another, drag it into the timeline and place it under the first video you just put in but in the bottom video track.
6 Play the video and watch it lag


  • NormanPCNNormanPCN Website User Posts: 3,945 Enthusiast

    Lagging is a common and normal forum complaint. You can always give the editor more work than it can do in real time on a given machine.

    Your media files are probably high overhead AVC. AVC has the highest decode overhead of any codec Hitfilm supports. This is just making the editor do more work. Maybe too much work.

    A transcode to something quicker can help immensely. Even my fast decode AVC settings. I have a 4Ghz 4770k and two simultaneous fast decode AVC files do not pose a problem. Other things like Cineform will perform even better.

    If you are recording video game stuff your files are probably very long (time). In the current versions of Express you will probably want to turn audio waveform display off with typical AVC MP4 media files. This can greatly improve performance with very long files. This also turns timeline thumbnails off but the performance benefits can be worth it. The next version of Express probably won't need this workaround but this is now and that will be then.

    I am assuming your two video files are actually separate media files and not two copies/instances of the same media.

  • liquidlegsliquidlegs Website User Posts: 8
    edited January 2018

    Hey Norman thanks for the reply

    After going through one of the Hitfilm tutorials i tried converting with some of the videos with some of the settings below using handbrake

    Encoder Profile=high
    Encoder level=auto
    FPS=Same as source
    Constant Framerate
    Extra options= keyint=15:min-keyint=1:bframes=0
    Presets-> General=Fast 1080p 30

    Viewing the media in the timeline is a ton faster now but still quite laggy. Yes the videos im using that are stacked on top of each other are separate files, but i have found that stacking 2 copies of the same video on top of each other on separate tracks will cause no lagging at all, only if they start and end at the same time. As soon as you move either top of the bottom video to end or start at a different time then it will lag again.

    Turning off the wave form for me makes no performance improvements at all, though i would actually prefer to have it on since im timing music in with other clips.

    Also the meters tab that sits next to the timeline that shows how high the frequency for the music is in each speaker, is there a way to increase the frequency that it can be viewed by in DB? I'm probably not making a lot of sense here but it looks the highest frequency i can see on the music on each speaker is 6DB, is there a way to increase it any higher?

  • NormanPCNNormanPCN Website User Posts: 3,945 Enthusiast
    edited January 2018

    It looks like you were trying to use the fast decode AVC settings but missed the mark. Or you did not properly list your settings here.

    You do not use any Handbrake presets and you must use the fast decode option. A shorter GOP (keyint) will help in a number of things, but not specifically your reported situation.

    Also, CRF 16 might be a bit high. It only makes bigger files which will require more CPU power to decode.

    Check out my fast decode AVC thread if you want to try and stay with AVC.


    As stated, Cineform is the best performing choice, and not by a little.

    "but i have found that stacking 2 copies of the same video on top of each other on separate tracks will cause no lagging at all, only if they start and end at the same time. As soon as you move either top of the bottom video to end or start at a different time then it will lag again."

    This is expected. Same media with offset simultaneous use performance problem in HitFilm. Luckily it should not be a common thing because boy does the performance get flushed down the toilet.

  • liquidlegsliquidlegs Website User Posts: 8

    Thank you so much Norman! You are correct about the fast encoding option, i did forget to tick the box which id the reason why it wasn't listed in my last post.

    After you following your guide here: https://hitfilm.com/forum/discussion/42415/transcoding-to-fast-decode-avc-for-timeline-edit-performance

    everything has been running very smoothly, I am very impressed to see all the issues gone and that scrubbing back and forth is no longer lagging, It feels so nice to actually see.

    If i wanted to use Cineform for myself is there another transcoder program i need to use, or is there a script i can download that i can just install into handbrake?

  • NormanPCNNormanPCN Website User Posts: 3,945 Enthusiast

    Glad to hear you are up and running. There really is a difference in performance from typical AVC and AVC using settings for fast decode.

    For Cineform transcoding you have a number of options.

    First you might look into VirtualDub. There is a thread on that.


    GoPro studio, also free, might work with your source media and it has a nicer/easier UI. However, you need to download an older version of the GoPro software. They discontinued the "studio" program. GoPro Quik 2.3 is the one you want.

    The "master" transcode thread has some into on this. I say master as all the threads I have been giving you are linked to in the master thread.


    Finally, you can use Hitfilm to transcode to Cineform. It is not as flexible as a normal transcoder and will give you different output filenames from your source. Also, Hitfilm will not transcode as fast as the above options. With Cineform the Medium or High options are your goto choices.

  • Stargazer54Stargazer54 Moderator Moderator, Website User, Ambassador, HitFilm Beta Tester Posts: 2,720 Ambassador

    To second Norman, I use the native Cineform within HitFilm to transcode.  And yes I wouldn't go above High or Medium.    I have gotten good results at the High setting.  File sizes aren't much larger than the original.

    As far as time to transcode, the convenience of keeping the workflow within HF outweighs the advantage of transcoding with GoPro Quik.  Transcode times aren't that much different.  Pull all your clips onto the timeline and output to Cineform.  While that grinds away, go get a cup of coffee, read the paper ... you're going to wait anyway whether you're going 3rd party or use native in HF.

  • NormanPCNNormanPCN Website User Posts: 3,945 Enthusiast

    It should also be noted that if you are starting with variable frame rate sources, that you will want/need to use VirtualDub to transcode to Cineform. 

  • liquidlegsliquidlegs Website User Posts: 8

    Cool Thankyou so much both of you!

    This might be a little off topic but if the video you have put together in the timeline lags in the viewer, it is possible that if you export your video that it will look the way it does in the timeline?

  • Triem23Triem23 Moderator Moderator, Website User, Ambassador, Imerge Beta Tester, HitFilm Beta Tester Posts: 18,275 Ambassador

    No--the Viewer window in Hitfilm is attempting to show you your project as it's being composited together and having effects applied in real time. Once you render you'll have a video file like any other video file and everything will play back smoothly.

    Remember the Viewer also lets you turn down resolution and quality settings. The viewer resolution/quality settings DO NOT HAVE AN EFFECT on the final exported render, but will internally sacrifice resolution or effect quality for smoother playback during editing.

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