Footage is smooth in Windows player but not when put into Hitfilm

I have a short video of gameplay and the video itself is very smooth in the Windows media player app. Though when I import the video and put it into hitfilm it is choppy and looks bad. Any fixes or advice is appreciated.

Comments

  • tddavis
    tddavis Moderator, Website User Posts: 4,889 Moderator

    @funnyapenoises Video game xaptured footage is more than likely Variable Frame rate footage and while video players handle it with ease, video editing programs are doing tons more calculations with the footage and choke on it. This is very true of HF. Transcoding to CFR or Constant Frame rate before trying to edit should solve the issue. You can verify cfr/vfr with a free program called MediaInfo and a Youtube search for it will turn up a couple of tutorials on how to use it. Also, FilmSensei did a nice tutorial on using Handbrake (free) to Transcode.

  • Triem23
    Triem23 Moderator Moderator, Website User, Ambassador, Imerge Beta Tester, HitFilm Beta Tester Posts: 19,580 Ambassador

    Knowing your system specs - CPU, GPU, OS, RAM and Storage - might be helpful.

    Knowing more about the video file would be helpful. There's a program called MediaInfo (it's free). Generating a "Tree" report and posting that here would be useful.

    MediaInfo tutorial:

    General notes:

    A media player is different from an NLE. Media players stream and discard frames and are less known for issues resulting from Variable Frame Rate (VFR) footage (NOTE: your screen recorded footage is probably VFR) or other issues.

    An NLE, like. HITFILM needs to decompress and "hold" a frame for processing. Once you add footage to a Timeline Hitfilm has to "think about" it even if you haven't added any effects, done animation or rescaled the footage, Hitfilm still has to check before it says "do nothing, just render."

    This has never been confirmed for me by a dev, but they've also never said "you're wrong" the dozens of times I've said this, but, I think 2D video layers in Hitfilm are textured polygons. The processing and texture map takes processor cycles.

    Back to "fully decompress and hold for processing." Video formats like mp4 and h.265 are highly compressed formats - in the industry they are called "delivery" codecs because they were designed to cram data into a small file size for streaming, fitting on a DVD/Blu-ray, or emailing. Delivery codecs are NOT intended for editing. (Codecs for editing are "intermediate" codecs). The more you cram a file the harder the computer has to work to decompress. Mp4/h.265 are "Long Group of Pictures" (Long GOP) codecs. This means that a "complete frame" might be stored only once every 30-300 frames, with frames in between stored as the "difference" from the prior frames. Particularly small files save more space by having "difference" information interpreted from prior and future "complete" frames. If you've ever skipped location on an internet video and seen a pixel mess with a moving section that "snaps" to a normal video after a few seconds, what you saw was the stream playing "difference frames" from the last complete frame before you skipped. The video snapping to normal is reaching the next complete frame.

    H.265/mp5/HEVC performs slower than h.264/mp4/AVC. The smaller file size of h.265 makes it more sluggish. Speaking of file size...

    Screen capture videos are tiny. Odds are your video is 5-6mbps Uncompressed 1920x1080 is over 1.45 gigabits per second, so you're talking about compressing something from 1,450 to 5. This is a massive ratio. Intermediate codecs tend to much much larger - maybe 200mbps for 1920x1080 30fps footage. The lower compression is part of why they perform faster. It's easier to decompress footage at a roughly 8:1 ratio than a roughly 280:1 ratio.

    Your screen cap is probably using a GOP between 120-150... Now, remember the media player just streams frames to the screen and moves on, but Hitfilm (and every other NLE) has to hold a entire frame to process it and add effects or change scale. This means when looking at a difference frame Hitfilm can't just write the difference data to the screen, but has to hold a complete frame. With Long-GOP media that's processing every frame through the whole GOP to extract full frame data to process. This takes time.

    So, there are slowdowns inherent in ANY NLE compared to a media player, and one thing (texture mapping) I think is Hitfilm specific.

    Knowing your specs will help us determine if you have "normal" slowdown or not. I'll say here if you don't have a dedicated GPU then slowdown is definitely expected.

    Knowing your video specs will help make specific recommendations on improvements. However, based on knowing how codecs work and how Hitfilm works I can make some recommendations that will probably stand.

    Chances are almost 100% you'll need to transcode your videos before import to Hitfilm

    • NLEs don't like really long video files. Media imported into Hitfilm gets cached, but super long files just take more processing power. If you're trimming sections from a long file Hitfilm has to skip to another location in the same file. This can actually take longer than skipping to a new file. Breaking a two hour recording into 10-15 minute chunks increase responsiveness and stability.
    • Earlier I brought up VFR media. VFR media saves space by changing the record rate. You may be recording "30 fps," but are REALLY recording "30, 24, 23, 30, 30, 18, 5, 33, 31, 5, 24" (not an exaggeration - we had a forum user last week with "30fps" VFR that ranged between 30fps and 0.5fps!). NLEs need a steady clock. If Hitfilm is trying to figure out how to make "30, 24, 23, 30, 30, 18, 5, 33, 31, 5, 24" fit into "30, 30, 30, 30, 30, 30, 30, etc..." that takes time. VFR can also cause audio sync issues, so VFR footage should always be transcoded to CFR (Constant Frame Rate) footage before import. You can set up CFR and splitting to smaller segments in the same transcode. Phones, tablets and web cams almost ALWAYS record VFR. Most screen capture software is VFR by default. Some screen captures can be set to record CFR. OBS can.
    • The smaller the file, the slower it performs. The longer the GOP the slower it performs. Transcoding can rewrite the file in an easier to use format. Intermediate codecs are a good choice, but use lots of drive space. However, even mp4 can be speedy if optimized. Forum user NormanPCN developed and tested settings to optimize Mp4. A video showing the "NormanAVC settings will be below.

    This video discusses all the above in a bit more detail, but, at about 19:30 goes into using MediaInfo to inspect footage, then discusses multiple ways to transcode. The Handbrake section at about 22:30 lists the NormanAVC settings.

    Odds are high after you post specs and a MediaInfo report we'll nod and refer you right back to this post and video link, but let's confirm specs and MediaInfo just in case you have something strange going on.

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