What Happens When You Go Through An Upload/Download Cycle From Youtube 1,000 Times

Have you ever asked yourself what youtube us dong to your video files when you upload them? If nothing else, youtube has to convert your video to a format that it later streams online.

Chicago based Musician and Video Artist, Patrick Liddell, actually went through this experiment. He discovered that as with all conversions, some data is lost. at about 10 iterations there is a noticeable distortion, and at 50 iterations, the video and voice looks like a bad photoshop filter.

Reading at Patrick’s blog, is seems that this was done manually over a period of one year.

Patrick also learned that youtube cuts a few frames with each upload rendering the video shorter and shorter.

Here is one question I am pretty sure everyone wants the answer for from Patrick’s blog, which explains where the data-loss occurs.

I thought digital copying was lossless. Why does the video quality get worse?

When copying files, the information is lossless; i.e. no matter how many copies are made they are all exactly identical to the original. This is just bit-jockeying. But what I am doing here is transcoding the video twice per upload. Each time the video gets uploaded to YouTube, it gets translated to the .flac/H.264 video codec — a process that makes the video smaller but loses some of it’s information. Then this loss happens again when I translate it again to mp4 format on my computer. Each time the pieces of information lost are saved on subsequent versions, and accumulated throughout the process

[I Am Sitting In A Video Room FAQ, video via DrMa]