I noticed that a certain video had several ‘versions’ and all of them were the same 1080p resolution, but they all differed in sizes. Some versions differed by a few MB, but it could range from around 300 MB to more than 1.5 GB! All of them have the same length and resolution and are exactly the same video. Also, a 720p version of that video was twice the size of some of the 1080p versions despite it being the same video.
I noticed something similar in some other videos as well. They all have the same length and resolution, and are even the same video, but their sizes differ by several times. Why is that the case?
In: Technology
They would be the same if they were both uncompressed (and the same codec & color space). But that’s a gigantic file size and YouTube and Netflix don’t want to be streaming those huge bitrates. So most videos are compressed, where they do their best at reducing the bitrate without a huge noticeable change to the quality.
Tom Scott has 2 videos on this (as of course he does):
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