It is amazing just how much memory and resources are required for digital video … or rather I should say, it is amazing that technology has developed to make it possible to access, stream, store, and edit digital video without crashing even the most capable computers. That technology can “hide” the enormous complexity and resource “expense” of video.
Consider a theoretical single frame that will go into an HD video: 1920 x 1080 pixels, each pixel encoded with 8 bits per color using RGB. That’s 3 bytes per pixel, times 1920, times 1080, for a total of 6,220,800 bytes. That’s one frame … what about 1 second of video at 30 fps? Multiply times 30, and now we are at 186,624,000 bytes. What about 1 minute of video? Multiply times 60, and now we are at 11,197,440,000 - more than 11GB. But wait - my 30-minute .mp4 video only takes up 2.3GB on disk; how is that possible? Welcome to the technology that compresses that data 3 different ways - by how it encodes each pixel (pixel format - not RGB but YUV, with different options for how many bits it actually stores of each); by how it encodes each frame (if your video is only 2.3GB, then it is using a “lossy” method that saves a ton of space at the expense of losing a little bit of detail - spatial compression); by how it encodes the stream of frames (time compression - generally only recording a full frame every so often, and recording just the “changes” between frames otherwise).
Again, the absolutely amazing thing is that modern technology can compress this enormous amount of data in a reasonable time frame (which you see when you export the video), and can take the compressed data and reconstruct the enormous data stream on the fly. But never forget that an incredible amount of data and an incredible amount of work is going on behind the scenes.
All this to say, 8GB, or even the 16GB that I have on my laptop, sounds like an awful lot of memory, way more than will be needed to handle that 2.3GB .mp4 file … not so much. The amazing thing is that we can accomplish so much “just” with 8 or 16GB of RAM!