SOLVED: HWA AMD VAAPI Stuttering

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Quick look? This right here:

Code:

-filter_complex "[0:3]scale=s=1920x1080:flags=fast_bilinear[sub];[0:0]setparams=color_primaries=bt709:color_trc=bt709:colorspace=bt709,scale_vaapi=format=nv12:extra_hw_frames=24,hwdownload,format=nv12[main];[main][sub]overlay=eof_action=pass:shortest=1:repeatlast=0,hwupload_vaapi"

You have more complex subs being burned in through a complex filter and the video is being scaled in the stuttering transcode. I'll look more in-depth in a bit when I have time...