03-09-2016, 08:00 AM
(This post was last modified: 03-09-2016, 08:03 AM by SERIOUSLY THOUGH.)
(03-08-2016, 10:58 PM)retrolinkx Wrote: Honestly, the question just wanted sound and sight. It wanted it for 70 years but made apparent that "one third is spent sleeping" so I'm assuming it wants me to factor in that into the calculations.
Looking at some stuff online, I've worked out that audio being recorded at a sample rate similar to CD's would be around 261TB of data. Which isn't a bad assumption. I already estimated using other data that it would be 264TB and this was an overestimate. So I think that's right.
As for the video. I must be messing up the calculations again. I think I've got the right idea but something isn't going right.
You only know there is 1 million pixels on the screen, 3 bytes per pixel and the video is recorded in 30fps. And there are two cameras, meaning the result is doubled. You're somehow supposed to come up with how much time 47 years would take up.
I'm getting around 16283TB's. So I already know that's wrong.
If anyone could help me out here, I'd be really grateful. It's already 4am.
I'm no expert on audio-visual recording, but here goes :
70 years of data.
VIDEO - 1 megapixel screen (720p is 921k pixels so I'll work on that, because no-one has a 1000x1000 screen, though you could argue that 1080i switches between two 1-megapixel frames). 5 megabits/second = 0.625 megabytes/second.
Stereoscopic recording doubles that input (we'll ignore overlap, as both images are used by the visual cortex to create a 3D image) so Video = 1.25MB/second
AUDIO - 256 kbits/second for the audio = 0.032 megabytes/second. We have two ears, double the audio input. Therefore - Audio = 0.064MB/second
Per day = (86400*1.25)+(86400*0.064) = 108,000+5529.60 = 113,529.60MB
Per four calendar years (to compute leap years) = 165,686,745.60MB
Four years fit into 68 17 times. So 165,686,745.60*17 = 2,816,674,675.20MB.
Add two more standard years to reach 70, and you get 2,816,674,675.20+(41438304*2) = 2,899,551,283.20MB
2,899,551,283.20MB = 2,899,551.28GB = 2,899.55TB of data.
For 47 years of data, you get 1,946.84TB of data.
Don't take that as kosher, it's what I could scribble down before going to work.
It doesn't take into account compression (the 5mbps [1.25MBps] standard I used leads to 9Gigabytes for a 2-hour film). For example, compression akin to a 1GB file for a 2-hour film would divide the final figure roughly by 9 (322TB for 70 years, 216TB for 47 years).
It also doesn't take into account variable bit-rate. For example, you could argue that pure black input, during the sleeping periods, creates more or less data (based on whether a black pixel means more data storage than a white one). That might be too picky.