This is topic 90 Minute CD-R's in forum Film-Yak at Film-Tech Forum ARCHIVE.
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Posted by Joe Redifer (Member # 3) on 05-07-2001, 06:07 PM:
I've heard that new 90 Minute CD-Rs exist, but they are not yet available in the USA. Has anyone else heard this? If so, would they be able to play on most normal CD players? Or would new CD players capable of playing these CDs need to be purchased?Also, has anyone else noticed that 74 minute CDRs say they can hold only 650 megs, but 74 minutes of audio is actually about 750 megs? Same holds true with 80 minute CDRs...they claim to hold only 700 megs, but 80 minutes is slightly over 800 megs!
Must be a data vs audio thing.
Posted by Evans A Criswell (Member # 381) on 05-07-2001, 09:23 PM:
My guess would be that the overhead of putting a file system on the disc (formatting information) would reduce the amount of storable data.Let's see: 74 minutes times 60 seconds per minute times 44100 samples per seconds times 4 bytes per sample (stereo) gives a total of 783216000 bytes, or 746.9 megabytes. Interesting. I wonder if parity or redundancy in storing the information may be part of the reason as well? I'm curious about this. Using the above logic, 80 minutes is 846720000 bytes, or 807.5 megabytes. I'm also curious if the 74 minute and 80 minute nominal CD capacities are exact.
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Evans A Criswell
Huntsville-Decatur Movie Theatre Info Site
Posted by Sean Weitzel (Member # 244) on 05-07-2001, 09:38 PM:
Haven't heard or researched the new 90 min discs, as for storage sizes, Evans is partly correct, in that in storing data on a CD-R, formatting takes up some of the available space. In addition, computer data must be very exact and very immune to surface defects on the CD media, thus, additional storage space is used as sort of an added redundancy to counter possible read errors due to defects. I believe this error correcting code is called reed-soloman. Audio, does not need as much media based error correction as audio cd players have this error correcting ability built into the hardware.
Posted by Jonathan Haglund (Member # 807) on 05-07-2001, 11:57 PM:
90 minute cd's are not an official spec, just like 150mhz ram. You can technically use the CD to 90 minutes using "overburn," a featre only found in certain burning software, but there could beproblems because the CD-R standard says the max is 79:59 min, and thus readers based on this standard may be unstable.
Titles able to do overburning include, but are not limited to:Nero 5.0.3.8
CDRWIN 3.8C
WinOnCD 3.8 Power Edition
DiscJuggler 3.00.758
Feurio 1.52
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Jonathan Haglund
Edwards Theatre Circuit, Inc
Park Place 10
Posted by Mike Blakesley (Member # 26) on 05-08-2001, 01:42 PM:
I once made up an 80-minute CD, but then mistakenly burned it onto a 74-minute blank. I got about 78 minutes onto it.I've been meaning to put together a 90-minute program and then see how much will ACTUALLY fit onto an 80-min. disk.
BTW I use Sonic Foundry CD Architect and a Yamaha CD burner, if anyone's wondering.
I'm sure that many players would choke on overburned disks.
Posted by Jonathan Haglund (Member # 807) on 05-08-2001, 07:48 PM:
BTW, the only way to copy Playstation games is to use overburn.Also, the difference between 74 and 80 minute discs is that the "tracks" are placed closer together. In a 90 minute, the tracks are a little closer, but most of the extended space comes from overburning.