Comment on Why hasn't video quality improved much over the past ten years?
JackbyDev@programming.dev 1 week agoIs that “real” uncompressed or using a lossless compression? Or are uncompressed video streams inherently losslessly compressed because they only show changes, not sending a full image every frame?
infinitevalence@discuss.online 1 week ago
Ok, since were (as a group not you specifically) are getting pedantic, I should clarify that any recording of video is inherently compressed. There is no way to capture 100% of an image ever. There is optical compression created by the lenses, then their is encoding compression created by the Analog to Digital conversion, or if capturing in analog there is physical medium compression. Film has grain size and quality which limits it resolution, analog tape is limited by the speed, width, and magnetic medium density.
So for the sake of this larger discussion Uncompressed should probably refer to the point at which the content is being captured to a medium regardless of what that medium is.
Now in the context of broadcast and professional video production Uncompressed means specifically that the transport and capture of the content is dont done with the removal of any part of the data. Now even that is a little misleading because the sensors on most professional cameras can capture higher data rates than 12G, but the transport specification only allows for 12G we have to use chroma sub-sampling to go from 444 to 422 when we put the content onto the wire.
So all that said, when I talk about Uncompressed UHD video requiring 12G I mean that no codec is applied, and no frames are dropped. We are running at the maximum specified bandwidth of our link which is 12G UHD video at 59.94 frames per second. Every pixel is written every frame regardless of if its a camera pointed at a wall watching paint dry or not.
So, last thing on Lossless compression, as a professional I frequently take issue with codecs that claim lossless quality because frequently I can see the difference between the vast majority of compressed formats vs uncompressed formats. Sometimes instantly, sometimes it takes a few min before I see the compression. Lossless compression generally is one of theos 9 out of 10 doctors things were the majority of people say they cant see a difference therefor they can claim its “lossless.” I can frequently see the difference between 444 and 422 chroma subsampling, and that is not even considered compression. I am one of the annoying people who walks into a bar and asks why all the HD tvs are set to “fill” on an SD channel.