Wetlook World Forum

Higher quality video requires more processing power to decode. Not only are the file sizes larger, but every frame of video is larger (wider and taller), so there's more computation required.

Videos on a computer only contain a tiny fraction of the original information. Video playback involves a "just add water" process that reconstitutes the full video frames from the partial information in the file, and if your PC is too old, it simply cannot perform this process in real time. If the time that your PC takes to process 1 second of video, takes more than 1 second, your video won't play properly. What often happens is that the video will get so far in, and then just hang for several seconds, or you might find that the video and audio get increasingly out of sync (which happened to one video in particular on my old PC, a Dell OptiPlex GX270, Pentium 4 HT 2.8 GHz — the video would play in slow motion while the sound would play in real time).

Also, modern formats achieve smaller file sizes using more intensive computation, and if your PC is really old, it won't have the oomph to handle the intensive computation required by newer video formats. Video compression is a complex subject!

In terms of Internet connections, Vidown is broken and doesn't permit download resumes: it ignores HTTP Range and misreports the size of all downloads by around +3 bytes, confounding download software into an eternal loop of thinking it's not got the full file, and being forced to start over. They refuse to ever fix this. As such, you don't need a fast connection, but you need one that's stable enough to complete the whole file without any interruptions, and without the use of any intelligent download software (browsers are by and large too stupid to care about whether the final file bears any resemblance to the stated Content-Length, which is why some websites get away with reporting bad data).