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Edit: Skip this and go read paulmd's comment, it's far superior: https://news.ycombinator.com/item?id=13886276 https://news.ycombinator.com/item?id=13886276 On

by jwarren 10y ago

Edit: Skip this and go read paulmd's comment, it's far superior: https://news.ycombinator.com/item?id=13886276 https://news.ycombinator.com/item?id=13886276 One reason for film's superiority as an archival medium is that you can hold a piece of film up to the light and see what it contains, whereas to see a digital archive you need to invent all the technology that leads up to decoding that particular file type. Disclaimer: I'm not a film archivist, but my partner is, so this is mostly second-hand knowledge backed up with quick google searches. There have been several different major types of film used throughout the year. Nitrate film was used from the late 1800s up until about the 1950s. It's highly flammable, and nowadays there are very few cinemas which are equipped to screen it. You need a very secure projection booth which can be well sealed in case of fire. It also burns without needing air, as it produces oxygen as part of it's reaction, which means that it's extremely difficult to douse with water. As it ages, the combustion temperature also lowers, and badly stored films may spontaneously combust. Despite all that, a properly preserved nitrate film looks phenomenal when projected. That was replaced with acetate film, initially known as "safety stock". It was initially thought to be pretty stable, but within a few years the decay (known as "vinegaring" due to the smell) started to set in. As with nitrate, proper storage can slow down the decay dramatically. This was used from the 50s until the 80s/90s. So there are these two historic film stocks, which were used in the production, archival, and distribution of every film for most of the last century, and they're both not fit for long term purpose. In the 80s, a more stable polyester film started to be used. This is the best film archival method available to my knowledge. It's shelf stable, and has proven itself in lab tests. This is what people are comparing digital archives to. Apart from the glib example at the beginning, I'm not going to try to argue the relative virtues of preserving the content of a film on film vs digital. However, the field appears to have a general acknowledgement of the importance of the medium of creation. So a digitally shot film would probably be preserved digitally (as well as possible) alongside any other medium.

cm2187 10y ago
> One reason for film's superiority as an archival medium is that you can hold a piece of film up to the light and see what it contains, whereas to see a digital archive you need to invent all the technology that leads up to decoding that particular file type. Realistically, unless these nukes are put to intensive use, we are not going to disinvent computers. But your point is certainly valid for codecs. The videos will require to be transcoded multiple times as old codecs become obsolete (who can read real media's .rm files today?)
- adventured 10y ago
  On the flip side, it wouldn't be extremely hard to create something to deal with .rm files either, which was demonstrated back then on several occasions. Seeing as the files are digital, and assuming proper storage, you have vast amounts of time to resolve the issue of reading .rm files, including directly requesting support from the engineers responsible for building out RealMedia's technology. The transcoding is trivial as far as problems go. We've been dealing with that non-problem for decades persistently and will continue to. The engineering skills needed will continue to exist to deal with it.
  - cm2187 10y ago
    Well, for .rm files, you might already have to pull engineers out of retirement. But what about in 30 years?
    - tgsovlerkhgsel 10y ago
      If there is reasonably common non-DRMed software that can play it today (e.g. VLC), running on a operating system common today, you probably won't have too many issues just emulating said OS and using said software. DOS 5.0 was released in 1991, over 25 years ago. There is a rather astonishing number of JavaScript based emulators that will let you run it in a browser. Even if the next 5 years of browser development break all of those emulators, getting a 5 year old portable version of Firefox that will run on current hardware isn't difficult. I don't think decoding video that can be played with VLC today will be a problem in 30 years, and I also think that 30 years after that, all you might need to do is another level of nested virtualization. If we assume that there will be sufficiently well working emulators capable of emulating a 2017 machine in 2047, just like there are such emulators for 1987 machines in 2017, and that at least the most common binaries will somehow be preserved, you should be able to recover most reasonably popular video formats in perpetuity. Compare that to analog material that rots and requires incredibly delicate handling by experts, while with digital media, you can let anyone try since they can't break anything. And finding a copy of a popular OS and player binary might prove easier than finding a projector/VCR that can handle the ancient format. Even if you were to recompress every 30 years, the loss will likely be less than from physical degradation of physical media. However, if you have a lot of video in one canonical format (down to using the same encoder and settings, so you don't have to worry about weird edge cases), you can just preserve a copy of the player and every 30 years, you make sure you can either port it to a current OS, or virtualize it efficiently.
criddell 10y ago
> So a digitally shot film would probably be preserved digitally (as well as possible) alongside any other medium. It's not like there's any real choice these days. YouTube has 300 hours of video added to it every minute.
- tlb 10y ago
  You'd need 300*60 = 18000 film cameras to keep up with preserving it all, plus some spare capacity for when you're changing film reels. If a film reel lasts an hour, it'll generate 18000 reels every hour, which should fit in a semi trailer. Not cheap, but entirely feasible.
- jwarren 10y ago
  Oh absolutely. I don't think even the film die-hards would suggest otherwise for most video produced today. I honestly don't know who actually does archive on film these days. I presume larger studios still do. I know film projection prints are still made for a lot of films, so perhaps an extra projection copy is made and stored in a studio vault.

by jwarren 10y ago

cm2187 10y ago

> One reason for film's superiority as an archival medium is that you can hold a piece of film up to the light and see what it contains, whereas to see a digital archive you need to invent all the technology that leads up to decoding that particular file type. Realistically, unless these nukes are put to intensive use, we are not going to disinvent computers. But your point is certainly valid for codecs. The videos will require to be transcoded multiple times as old codecs become obsolete (who can read real media's .rm files today?)

adventured 10y ago
On the flip side, it wouldn't be extremely hard to create something to deal with .rm files either, which was demonstrated back then on several occasions. Seeing as the files are digital, and assuming proper storage, you have vast amounts of time to resolve the issue of reading .rm files, including directly requesting support from the engineers responsible for building out RealMedia's technology. The transcoding is trivial as far as problems go. We've been dealing with that non-problem for decades persistently and will continue to. The engineering skills needed will continue to exist to deal with it.
- cm2187 10y ago
  Well, for .rm files, you might already have to pull engineers out of retirement. But what about in 30 years?
  - tgsovlerkhgsel 10y ago
    If there is reasonably common non-DRMed software that can play it today (e.g. VLC), running on a operating system common today, you probably won't have too many issues just emulating said OS and using said software. DOS 5.0 was released in 1991, over 25 years ago. There is a rather astonishing number of JavaScript based emulators that will let you run it in a browser. Even if the next 5 years of browser development break all of those emulators, getting a 5 year old portable version of Firefox that will run on current hardware isn't difficult. I don't think decoding video that can be played with VLC today will be a problem in 30 years, and I also think that 30 years after that, all you might need to do is another level of nested virtualization. If we assume that there will be sufficiently well working emulators capable of emulating a 2017 machine in 2047, just like there are such emulators for 1987 machines in 2017, and that at least the most common binaries will somehow be preserved, you should be able to recover most reasonably popular video formats in perpetuity. Compare that to analog material that rots and requires incredibly delicate handling by experts, while with digital media, you can let anyone try since they can't break anything. And finding a copy of a popular OS and player binary might prove easier than finding a projector/VCR that can handle the ancient format. Even if you were to recompress every 30 years, the loss will likely be less than from physical degradation of physical media. However, if you have a lot of video in one canonical format (down to using the same encoder and settings, so you don't have to worry about weird edge cases), you can just preserve a copy of the player and every 30 years, you make sure you can either port it to a current OS, or virtualize it efficiently.

criddell 10y ago

> So a digitally shot film would probably be preserved digitally (as well as possible) alongside any other medium. It's not like there's any real choice these days. YouTube has 300 hours of video added to it every minute.

tlb 10y ago
You'd need 300*60 = 18000 film cameras to keep up with preserving it all, plus some spare capacity for when you're changing film reels. If a film reel lasts an hour, it'll generate 18000 reels every hour, which should fit in a semi trailer. Not cheap, but entirely feasible.
jwarren 10y ago
Oh absolutely. I don't think even the film die-hards would suggest otherwise for most video produced today. I honestly don't know who actually does archive on film these days. I presume larger studios still do. I know film projection prints are still made for a lot of films, so perhaps an extra projection copy is made and stored in a studio vault.