There was also a special type of blank disc, the re-writable blank disc which was something like 10 bucks a pop at future shop.
I had a enterprising career in school at one point burning shared music mp3s that I pulled from Napster and selling them to friends.
In addition, I sometimes have par2 files on the DVD as well, though it's probably better to just have additional dvdisaster ECC instead.
It's a good idea to periodically go through all your old backups and transfer them to new media, or at least make sure the old media still works and start recovery on them right away if they don't.
 - http://dvdisaster.net/
 - https://github.com/Parchive/par2cmdline
This isn't the same tool I used, but it is derived from it, https://github.com/randombit/fecpp
I don't use optical discs much anymore, but I still like the idea of archiving things like family pictures on read-only media once in a while.
The biggest benefit of M-DISC for DVDs was that it didn't use an organic dye, as those dyes tend to decay over time. The dominant BD-R recording mechanism (HTL) uses an inorganic recording medium so isn't affected by this problem.
There are differences in how BD-Rs are manufactured that can lead to big differences in longevity  but there are regular retail BD-Rs that outperform M-DISC in accelerated aging tests . There are also DVD variants that outperform M-DISC .
Also, M-DISC hasn't produced any evidence for their BD-R discs. For their DVDs there were a few scientific studies they could point to that demonstrated their longevity, for BD-R they have no such evidence.
Unfortunately that data is eight years old and I'm not even sure if Panasonic and Sony even make BD-Rs anymore. Seeing a lot of out of stock Japanese imports on Amazon.de for both of them. I can really only find Verbatim BD-Rs and they didn't really perform that well in the comparisons.
I've actually been interested in BD archiving for a bit but haven't gotten into it yet because of the initial costs. I have about 1.1 TB of data that I'd like to archive for the long-term.
You can always import them yourself. Tenso and Buyee both work great.
I think it's just that the western market doesn't care for them much, so you don't see anybody bothering to import them for you.
My theory - and this is just a theory as I don't really know what's going on - is that the dyes in CD-Rs and DVD-Rs after laser exposure slowly regress back towards the original transparent state, and that very "fast" dyes combined with a very short exposure time ("up to 52x speed!") emphasizes this problem, while giving the dyes a longer exposure time prevents it by simply burning the dye opaque beyond "recovery".
For some reason this image just brought back a whole load of memories for me. Some of the first of these I encountered were previews of my Dad's music he would send me on those ever so dark green discs.
Or am I failing to grok the degree to which It's Complicated?
Very neat piece of software.
Is it the plastic or the metals breaking down? If it’s plastic, humidity probably has a bigger impact.
Lower temps are almost always better. Freezer is good. Hard to say if an oxygen absorber is helpful.
Or could sparge your container with nitrogen.
So far as home-burned CDs, they haven't lasted as well. Mostly because I didn't take as good care of them - I didn't have $18 or more invested in them (typical new music CD price in the 80's & 90's) so they were just tossed in a drawer.
You can have the reflective layer delaminate, but CD-R bit rot usually has no observable physical changes.
Really doubt I will end up using much more of them at this rate though besides using them as "retro" coasters.
I've taken dd images, but can't find a reasonable "archival" h265 profile that doesn't come out larger than the original.
If you want to merge related VOB files into one video file, that can be done losslessly with tools like tsMuxer.
- Take an ISO rip and never delete it since any additional encoding is a new derivative work of your data.
- Run it through MakeMKV to get a Matroska file for each title
- Assuming a video source (e.g. recorded TV shows or camcorder footage) use QTGMC to deinterlace the video from 60 fields per second to 60 frames per second. This will approximate the original look on today's screens by simulating the slight delay in the dimming of a CRT's phosphors after the electron beam excites them.
- Crop the video if any black bars are present. Many DVDs have 8px of dead area on the left and right edges because they are rooted in the D-1 4:2:2 standard and often have a program area resolution of 702 or 704x480: https://en.wikipedia.org/wiki/D-1_(Sony)
- Convert the chroma from SD colorspace to HD colorspace to avoid them looking washed-out on modern displays: https://en.wikipedia.org/wiki/Rec._601
- Decide how to handle the aspect ratio. People use "anamorphic" to mean "widescreen DVD" but that's kinda a misnomer because all DVDs are anamorphic: its 720x480 pixel resolution is 3:2, halfway between 16:9 and 4:3. Each title sets a flag telling the display to stretch it ±18.6%, depending. You can leave it like this, setting the same DAR flag, but I've come to prefer resizing it myself to a square-pixel resolution since I'm usually cropping it anyway and VapourSynth will do a way better job than most displays can do on the fly. I also dislike the idea of throwing away horizontal pixel data by resizing 4:3 video down from 720x480 to 640x480, so some times I stretch it vertically instead, to 720x540 (or 720x544 with 4px black along the bottom if you want to follow the ATSC 3.0 HEVC recommendations).
- Encode the video with x265. I have a personal "SD" tuning that I've been working on and would love to share once I can get some example clips together :)
- Encode the probably-AC3 audio with FDK-AAC. I find it handles voices and other things better than faac thanks to its low-pass step, but for very high-bitrate sources (like concert DVDs) I disable that by using VBR-5: http://wiki.hydrogenaud.io/index.php?title=Fraunhofer_FDK_AA...
- Mux your new streams together into a new MKV, and take a moment to fill in all the metadata fields the container provides. You can even attach a JPEG named "cover.jpg" and have it display as the icon in Explorer!
I do usually re-encode from from AVC to HEVC but with a more usual HD tuning. Not mine, but check out https://docs.google.com/spreadsheets/d/1u9fKNsRcLgc-1oVV5GhB...
Does that mean drives were first made with relatively robust ECC, and they just stopped using it for later drives? What would be the motivation to drop that?
I've long since abandoned using optical as a form of stroage...
The chemical processes are pretty much reversible, leading to dead CDs. The physical processes are much more robust, as you'd have to deform the actual base plastic, like cooking vinyl LPs in the sun.
In sum, some 3,800 CDs. I ripped them all a couple of years ago - I had problems with a handful, but EAC eventually got them all to disk. I examined the troublesome ones, but no (visual) signs of disc rot.
They did replace 300 with a Blu-Ray copy (this was after HD-DVD was obviously on its way out), but the rest didn't fail until much later or were bought used for literally pennies.
For pressed CDs, I can't ever remember getting one that was unreadable and not obviously scratched (though I did have a game CD shatter into hundreds of pieces in the drive).
I'm lucky that I've not suffered any rot yet but it's only a matter of time for me because I don't store them properly either.
One could extend the vinyl argument and say there’s no such thing as a storage medium without a failure mode. Cassettes have problems, HDDs can fail, even solid state systems only have a limited life. The best we can do is backup.
No. The best you can do is use mathematics to compensate.
In essence represent the data as a set of equations and generate extra ones that will be useful in case you lose one. They have been doing this for decades in telecom/storage.
You can have 10 TB of parity for a 1 MB file but if that data isn’t distributed then you’re still vulnerable.
So the problem is analog vs digital nor the lack of mathematics in vinyl; it’s that ultimately any form of storage media requires a physical device and physical devices are bound to the problems of the physical world.
This, by the way, is also why Amazon has multiple data centres in any given region. Why backups should always be stored off site, and why DR solutions are based in different physical premises.