Video lags


I have a problem that after export there are parts of the video that get lags.
For example, in the video below you can find it between 22:15 and 22:20 (and a few more places).

Recordings were made with an iPhone SE (30 fps) and a Sjcam SJ4000 (30 fps) camera in FullHD.

The pictures show the settings I used.

Can anyone help me out what the problem is?



  • @KrisztianOrban could you provide your machine specs if possible? Does the footage lag in another video player?

  • You should likely download MediaInfo (it's free) and generate a "Tree" report for some of your source footage and paste the report here. 

    (MediaInfo tutorial)

    @TheBenNorris IPhone footage and off-brand action cam? I'll guess this is a VFR problem. Looking at the timecode provided, right when the "lag" hits a large person walks through the frame which also causes the auto exposure to kick in. Suddenly, instead of some kind of delta compression the entire frame starts changing at once, which probably caused a huge variation in the source file. My immediate guess is a transcode to CFR (preferably before Hitfilm import) will solve/prevent this. 

  • @Triem23

    In the video above, the narrator has some kind of what I call "warble" in the sound. I had the same on a voice over I made using Audacity. I could not find a way to get rid of this after recording using Audacity.  Can you suggest something to help?


  • TheBenNorris  

    I tried with several players.

    Windows 7 Pro 64-bit SP1
    Intel Pentium G3260 @ 3.30GHz 
    8,00GB Dual-Channel DDR3 @ 666MHz
    MSI H81M-E34 (MS-7817)
    T32127 (1360x768@60Hz)
    Intel HD Graphics (MSI)
    111GB KINGSTON SHFS37A120G ATA Device (SATA-3 (SSD))
    TSSTcorp CDDVDW SH-224FB ATA Device
    Realtek High Definition Audio


  • Triem23

    I did what you asked for, so you thought?

    What does CFR transcoding mean? Can you help?


  •  @KrisztianOrban ; AS best as I can tell using Google Translate you meida is in Constant (ÁLLANDÓ) or CFR.  What Triem23 meant by CFR transcoding would be to make sure your footage was transcoded if it wasn't already in Constant which is by far the moist common cause of issues like yours.  I'll let Triem23 and the other file gurus give you any clues they can determine from your settings as I know very little about them.



  • @KrisztianOrban looking at your specs, you are using windows 7 (unsupported by us, and soon, microsoft too) and hardware that is fairly low spec, especially with an integrated graphics card. Hopefully the media info helps solve this issue.

  • @TheBenNorris sanity check me if I'm wrong but Krisztian is running a Pentium, which is, I think, well below minimum specs. Min specs for Intel are a 4xxx-series i3-class processor or higher. That Pentium is EOL since December, 2017.

    @KrisztianOrban unfortunately, I think your CPU, and GPU are under minimum specs, and your OS is not supported by the software. Support ended for your CPU/GPU in 2017, which means you're drivers are two years old. For perspective, my i7, which is NOT end of life, and my most recent driver date is this week.

    This makes it difficult to help you because the problem could be related to your GPU driver, which you can't update, an unsupported OS (and there are a couple of kniwn Win 7 related bugs that won't ever be fixed), and your CPU is under spec. The only option to resolve these issues is a new computer.

    There are some issues about your footage we can look at. Your footage is variable frame rate (VFR). This means the camera is changing record speed. As an example you might set your camera to "30 fps" and it really is shooting 30, 30, 30, 22, 21, 22, 30, 30, 30, 25, 20, 20, 30,etc. 

    This is a problem for editors. Hitfilm tries to even out the frames, but it doesn't always get it right. It's better to convert your footage into a Constant Frame Rate (CFR) format. CFR just means if you set your camera to 30 fps, it's recording 30.

    So, there are several ways to transcode your footage. 

    This video discusses, in detail, VFR and several ways to transcode. The "Handbrake" section has optimized Hitfilm settings. The video description contains timecode chapters.





  • @Triem23 the processor the user has was launched two years after the 4th generation i3 processors, which is why I do not believe they are completely below spec.

  • @KrisztianOrban I hope @TheBenNorris is right and I'm wrong. I think you're under spec, he thinks you are. I've been around longer (moderators are not FXHOME employees), but Ben is a Hitfilm developer. Believe him on this over me. 

    (Ben, I'm sure you've figured out I think I'm helpful, so, while I'll try to help catch you up, I'll be the first to own up when I'm wrong, or tag in someone more knowledgeable. 😊) 

  • @KrisztianOrban @triem23 after doing a spec comparison it does seem that although that pentium released two years later, it is significantly worse than the lowest of the i3-4xxx range and is therefore almost definitely below spec.

  • TheBenNorris, Triem23 and tddavis

    Thank you very much for your help!

    A year ago, I made a video with the same computer, with the same footage of the cameras. I made that video with Premier Pro CC and it was perfect.
    Because of this, not now, I'm buying a new computer.

    I just watched it in MediaInfo, the iPhone "variable" 28.517-30.000 FPS and the SJCAM videos "constant" 30.000 FPS.

    Do you recommend converting all videos to "constant"? Or just iPhone videos? How much FPS do I convert?

    Thank you!

  • @KrisztianOban All video files will benefit from converting to Constant Frame Rate.  If you leave it at variable then your CPU will have to do more work to interpolate frames.  Converting to CFR will help performance, no matter what editor you use.

  • Stargazer54


    And how much FPS do you think I would convert the videos to?

  • In your case, 30. The MediaInfo report in your pic 22222, near the top, where it says "Frame Rate 30fps" shows you the "desired" frame rate.

    In pic 11111 the "Overall bit rate mode - vaitizo" (sorry for the missing accents) is what's telling us its VFR. 

  • With "Handbrake" I did a video conversion.

    This image is in its original state:

    Here's the conversion:

    So will the video be good after export?

  • And one more question:

    if I want to put a video that is 25 FPS, should I convert it to 30 FPS?

  •  I'll jump in here and state that generally when you have VFR media you want to transcode it to the frame rate the "camera" was attempting generate. In the photo 3333, MediaInfo lists the targeted frame rate as 29.97. It lists the minimum frame rate as 28.57 and the max at 30.0. MediaInfo is really only guessing, via some average computation, at the the targeted frame rate. You kinda want to know what the camera was targeting. That said, most often, when a camera states 30fps it really means 29.97. This is a fine point but worth mentioning.

    If one is transcoding to generate CFR (constant frame rate) then you can really target the frame rate what you want/need. Whatever that frame rate is. So if your camera recorded 30fps but you really want 25 then just target 25 in your transcode. If you target 30 and then setup Hitfilm to 25 then Hitfilm is going to resample anyway, so just let the transcode get that out of the way first. It is also a possibility that the external transcoder will do a better job of the resampling than Hitfilm. In Hitfilm the resampling will be done every time the timeline is run/played. If done during the transcode the resample is done exactly once.

  • NormanPCN

    Thanks for the information!

    If I want to put an original 25 FPS video next to the converted 30 FPS video, what do I do?
    Should I convert 25 FPS videos to ---> 30 FPS?

  • edited December 2019

    I don't know if this is what you should do, but what I do is transcode all my media to what my final project is going to assembled in and rendered out as. So for example, say I have footage from the following devices...

    • My Nikon 3500 - Records at 23.976 Constant FPS
    • My LG G6 Cell Phone - Records at 60 Variable FPS for Slow Motion
    • My son's cheap underwater camera - Records at 15 Constant FPS
    • OBS (Video Capture Software) - Records at 29.97 Variable FPS into an FLV file

    Now say I want to assemble footage from all of those into a single project, and let's say I decide that is going to be final rendered at 29.97 FPS. I would transcode all of them into 29.97 Constant FPS and then bring those media into HitFilm for assembly and render.

  • Thank you all for the help, hope this will be the problem :)

This discussion has been closed.