YouTube introduces horizontal microstuttering despite clean 60fps CFR sourc

[Migue12HD]

Hi, I'm working with gameplay footage from Geometry Dash, recorded at CFR 60.000 fps in 720p. I upscale to 1440p and encode using libx264 in order to force VP9 on YouTube and preserve motion fidelity, but YouTube keeps introducing microstuttering during horizontal scroll scenes, even though the original file is visually clean.

Here's my FFmpeg command:



ffmpeg -ss 00:00:41 -i "source.mp4" -t 00:00:30 -vf "scale=2560:1440:flags=lanczos" ^
-c:v libx264 -preset veryslow -crf 16 -profile:v high -level 4.2 -pix_fmt yuv420p ^
-g 60 -keyint_min 60 -sc_threshold 0 -bf 2 ^
-b:v 40M -minrate 40M -maxrate 40M -bufsize 80M ^
-color_primaries bt709 -color_trc bt709 -colorspace bt709 ^
-x264-params "no-scenecut=1:force-cfr=1:qpmin=16:qpmax=18" ^
-r 60 -movflags +faststart



The original file is not 100% flawless—it has some fixed, minor shutters—but overall scroll fluidity is clearly present and consistent in local playback. After uploading, however, the result is much worse. YouTube playback loses all that smoothness entirely, turning it into constant micro judders, even with VP9 confirmed and full bitrate enforcement.


·The original video:
[Attachment 87500 - Click to enlarge]

·The uploaded video: https://youtu.be/8Hz6XvqWsAc?feature=shared


So my questions are:

·Why does YouTube still introduce stutter even with fixed GOP, CFR, and high bitrate?

·Is it possible YouTube injects hidden scene cuts or breaks GOP cadence internally?

·Are there any real, tested ways to preserve scroll fidelity for 60fps gameplay?

·Has anyone found a consistent method to avoid this issue, especially in horizontal scrolling games like GD?

Any insight or shared experience is truly appreciated.

[davexnet]

Unable to download your "attached file", it says bad browser request. Site error?
The youtube video shows 4 or 5 duplicate frames per second causing the stutter issue

[Alwyn]

Same here. When I tried to download your attachment, Chrome gave me this:

"Bad Request
Your browser sent a request that this server could not understand."

[Baldrick]

It must be something wrong with the file name. Try remove the 100% in the name and reupload the file.

[october262]

Hi, I'm working with gameplay footage from Geometry Dash, recorded at CFR 60.000 fps in 720p. I upscale to 1440p and encode using libx264 in order to force VP9 on YouTube and preserve motion fidelity, but YouTube keeps introducing microstuttering during horizontal scroll scenes, even though the original file is visually clean.

Here's my FFmpeg command:



ffmpeg -ss 00:00:41 -i "source.mp4" -t 00:00:30 -vf "scale=2560:1440:flags=lanczos" ^
-c:v libx264 -preset veryslow -crf 16 -profile:v high -level 4.2 -pix_fmt yuv420p ^
-g 60 -keyint_min 60 -sc_threshold 0 -bf 2 ^
-b:v 40M -minrate 40M -maxrate 40M -bufsize 80M ^
-color_primaries bt709 -color_trc bt709 -colorspace bt709 ^
-x264-params "no-scenecut=1:force-cfr=1:qpmin=16:qpmax=18" ^
-r 60 -movflags +faststart



The original file is not 100% flawless—it has some fixed, minor shutters—but overall scroll fluidity is clearly present and consistent in local playback. After uploading, however, the result is much worse. YouTube playback loses all that smoothness entirely, turning it into constant micro judders, even with VP9 confirmed and full bitrate enforcement.


·The original video:
[Attachment 87500 - Click to enlarge]

·The uploaded video: https://youtu.be/8Hz6XvqWsAc?feature=shared


So my questions are:

·Why does YouTube still introduce stutter even with fixed GOP, CFR, and high bitrate?

·Is it possible YouTube injects hidden scene cuts or breaks GOP cadence internally?

·Are there any real, tested ways to preserve scroll fidelity for 60fps gameplay?

·Has anyone found a consistent method to avoid this issue, especially in horizontal scrolling games like GD?

Any insight or shared experience is truly appreciated.

try what is in this reddit thread - https://www.reddit.com/r/ffmpeg/comments/1h2y711/using_ffmpeg_to_remove_slight_stuttering_effect/

[Selur]

About the link: seems to be a bug in the board software.
Board creates:

https://forum.videohelp.com/attachments/87501-1750351558/OLD%20TRAP%20100%%20-%20Proyecto_09-02_Full%20HD%201080p.mp4

as link, but it doesn't escape the '%', working url is:

https://forum.videohelp.com/attachments/87501-1750351558/OLD%20TRAP%20100%25%20-%20Proyecto_09-02_Full%20HD%201080p.mp4

Cu Selur

Ps.: In Vapoursynth or Avisynth, one could 'fix' it by replacing the duplicates with interpolations. (no clue whether this can be done with ffmpeg)

[Alwyn]

Now I'm only an enthusiastic amateur at this game so I could have it wrong but it looks to me like the ORIG 1080 file and the YT file are exactly the same, to the frame, so the issue must be with the YT server or the YT browser player. Here they are, side by side.