eli5-Why do blu ray rips have such a large file size, but a file i downloaded through torrenting is a fraction of the size.

Question

So ive been making backups of my movies by ripping my blu ray collection and filling in the gaps with torrenting. I have noticed that a 1080p movie will take up 20-40 gb if i rip it from a disc, but if i just find a torrent online its usually 5 gb or less. Both are in the MKV format

In: Technology

Answer 1

You always can compress a video more by making the quality worse. In general a smart compression system can take a lot away before you notice. If you looked pixel by pixel at the original and the compressed version there would be lots of little “two pixels that were almost the same shade of yellow are now the same shade” in ways that good compression is designed about you not seeing much difference