Several reputable sites host royalty-free or demo footage for download. Channels like LumaFusion, DJI, and specialized AV forums host direct-download links. Look for formats like .mp4, .mkv, or .mov to ensure compatibility with your preferred media player (such as VLC or MPC-HC).
Once you have downloaded your sample, look for these specific visual challenges: 8k video download sample
Using yt-dlp:
yt-dlp -f "bestvideo[height=4320]+bestaudio" --merge-output-format mp4 "VIDEO_URL"
Before hitting download, look at the file name. You want to see: Several reputable sites host royalty-free or demo footage