25-06-2020, 02:39 PM
(This post was last modified: 25-06-2020, 02:42 PM by ppppenguin.)
Here's a short intro to offline editing: https://en.wikipedia.org/wiki/Offline_editing
The important point, even today with powerful computer based systems, is that you make the edit decisions with a lower quality copy that's cheap and easy to manage. Then the full quality masters are edited using the edit decision list to conform with the offline edit. Even with current technology it would be wasteful to edit an HD or 4K program using full resolution material. The amount of data, in uncompressed or minimally compressed form is enormous. For example 1080/50p HD video is usually carried on a 3Gb/s link. You can store a bit less because some of that is blanking intervals. You can also apply lossless or minimally lossy compression and come down by perhaps a factor of up to 5. That's still 600Mb/s. A modern TV centre will use at least 40GB/s fibre ethernet for its main internal networks and have huge disk servers. Backed up by robotic data tape servers. By comparison it's dead easy to keep standard definition files available with quick or instant access for offline editing on an ordinary PC.
It's a long way from 2" tape and a small axe
The Smith microscope, as used for physical editing of 2" tape, is difficul to google. Found this by googling "Edivue", the magnetic fluid used to reveal the tracks ont he tape: http://www.vtoldboys.com/editingmuseum/smith.htm This site is well worth a look if you're interested in the history of video recording, some of which is akin to black magic: http://www.vtoldboys.com/editingmuseum/index.htm And its parent site: http://www.vtoldboys.com/
The important point, even today with powerful computer based systems, is that you make the edit decisions with a lower quality copy that's cheap and easy to manage. Then the full quality masters are edited using the edit decision list to conform with the offline edit. Even with current technology it would be wasteful to edit an HD or 4K program using full resolution material. The amount of data, in uncompressed or minimally compressed form is enormous. For example 1080/50p HD video is usually carried on a 3Gb/s link. You can store a bit less because some of that is blanking intervals. You can also apply lossless or minimally lossy compression and come down by perhaps a factor of up to 5. That's still 600Mb/s. A modern TV centre will use at least 40GB/s fibre ethernet for its main internal networks and have huge disk servers. Backed up by robotic data tape servers. By comparison it's dead easy to keep standard definition files available with quick or instant access for offline editing on an ordinary PC.
It's a long way from 2" tape and a small axe
The Smith microscope, as used for physical editing of 2" tape, is difficul to google. Found this by googling "Edivue", the magnetic fluid used to reveal the tracks ont he tape: http://www.vtoldboys.com/editingmuseum/smith.htm This site is well worth a look if you're interested in the history of video recording, some of which is akin to black magic: http://www.vtoldboys.com/editingmuseum/index.htm And its parent site: http://www.vtoldboys.com/
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
