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Could CDRW Disks Replace Videotapes?
NewtonsLaw asks: "I'm in the process of building a TiVo-like PC that uses off-the-shelf technology to implement video timeshift, MPEG recording, MP3 recording, etc along with Net-radio functionality. Over the past two months I've effectively replaced VHS video tapes with CDRW disks. Once a program has been captured on the PC in (S)VCD MPEG format, I can either watch it by playing back the recorded file or dump it onto a CDRW and watch it on my DVD player, before blanking the disk and returning it to the 'empty' pile. What I've noticed is that most of the CDRWs I've tried only last about 30-40 rewrites before they start showing significant data dropouts (almost always at the start of a recording). Since disks in (S)VCD format don't carry the same level of error-checking/correction as disks written in regular data format, such dropouts are more noticeable than they would otherwise be (of course the up-side is that you get to store 805MB on a 700MB CDR/RW without overburn).
What I want to know is -- how many rewrites do most people expect from their CDRW media? I seem to recall seeing a figure of a thousand rewrite cycles being touted by some manufacturers. Is this realistic? Thirty rewrites makes a $2.50 RW disk an economic medium for this purpose but it seems a hell of a long way short of 1,000."
"I've tried CDRW disks from several manufacturers and they're being used in a new Sony CDRW drive which seems to function just fine. I've also encountered a slightly shorter lifetime for CDRW media when used for (S)VCD disks and written by a slightly older HP CDR/RW drive.
And before anyone asks 'Why don't you just play directly from the HD?', I should point out that I have to share the TV gear in this house with the rest of the family so it's just easier to burn their stuff to disk and let them use the DVD player than to fight over access to the TiVo-clone."
If I remember correctly, the CD-RW blanks I have at home (14x compatable) say they are "guaranteed" for 100 re-writes.
Also, what speed are you burning on these CD-RW's at? Maybe you should try lowering the recording speed and seeing if you still get the drop outs.
Not All Who Wander Are Lost
My personal experience is that a nice quality video doesn't fit on a 700MB cd-rw. Not unless there is significant amount of compression and then the quality suffers. That is my only bitch, IMO CD-RW's are easy to create, play, and store. Not quite as convienant as tape, but in the future it very well could be!
Hold up, wait a minute, let me put some pimpin in it
Even with normal data, the samsung burner, made the CDRWs I used lose data already after 4-5 burns. I think for permanent storage, normal CDr's are good, but I wouldn't trust CDRWs too much with any of my computer data or audio/video.
http://www.inspirelight.net/
Typicly I will reuse my CDRW disks arround 10 -> 15 time, but im storeing my programs, mp3 backups, and web dev work... so once its backed up to my satisfaction... I stop...
:)
Personaly I think that to acheve 30 -40 rewrites to a VCD disk with no real loss in quality beats the shit out of a VCR which you only really get 4-5 rewrites out of before you start noticeing quality issues...
Keep up the good work, and keep us informed as to when we can buy the set top version of your system
The Code Ninja is swift with his tool, precise in his delivery, and deadly accurate in his execution.
...From various places. I have a low-end P3550 and a video out-card hooked into my home entertainment system. CDR and CDRW has all but replaced VHS for me.
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There are basically two reasons to save:
1 You don't have the time to watch while the program is being broadcast. Save it on the TIVO hard drive and see it later that night or two days after or whatever. Then delete.
2 You have a genuine interest in the program and want to save it for the future. Then save it on a disc, and don't overwrite it.
Tor
One of the small-town grocery stores nearby actually sells CD-Rs and CD-RWs at pretty decent prices, and place them next to the blank VHS tapes in the store. Seeing as to how they're becoming more ubiquitous, and devices like the Terapin VCD Recorder (at http://www.thinkgeek.com/electronics/video/57a6/) are starting to appear, perhaps CD-RWs could give VHS a run for its money, with comparable video and audio quality, as well as interoperability with a computer. For instance, you just missed Everybody Loves Raymond, so you hit KaZaA and somebody uploaded a VCD for you. So yeah, they've got their merits.
-
And the Angel said unto me, "These are the cries of the carrots! The cries of the carrots!"
Because it's hard to play a hard drive in a DVD player.
Figure $5 for a pack of 50, so $0.10 each -- you can't re-record on them, but it shouldn't cost you more than CD-RWs that start failig at 15 uses or so. Plus, this way you have the ability to create instant archives of your favorite shows, or just discard the used disks.
The CDR will never replace vidoetapes for the same reason HDTV is only just starting to bloom and cassette tapes were EVER on the market.
People don't care about quality! If people cared about quality Microsoft would be out of business, Airlines would have decalred bankupcy years ago, and NO ONE would eat fast food.
Unfortuately people care about how little effort they have to excert to get something done. People don't want to deal with CD-R's because, despite an overall decrease in effort required, short term effects are minimal.
On a side note: CDRs would be a great alternative to video tapes. Tape media sucks
Help I'm a rock.
storing video on punch cards. This would be great for editing as I could just pull out a stack of cards and insert it into another stack.
Has anyone else done this?
Answering your question would be a violation of the DMCA. Sorry, ask Jack and Hillary.
"Eve of Destruction", it's not just for old hippies anymore...
This is an ongoing discussion at Plasma. People with the bucks have been contemplating this for a while. Be sure to read up on the forums for the technical details as well. More info here.
Please note there are solutions that require money. How cheap are you going to be?
If we don't fight for ourselves no one will.
Insert disk and hit record, for a price point of $200.00 when it is in volume. And 2.40 for a CDRW?!? Just jump to DVD(+-) RW. They are only $6.00, and getting cheaper, and would hold about as much as a long video cassette at similiar quality. Also, tapes are not reliable either. They are only good for about 100 plays.
The law is a weapon of the government, not a protection for the likes of you. Surely you understand that.
Are you sure the discs are not getting dirty w/fingerprints, dust, etc.? Such things can cause a lot of the problems misattributed to media failure...
.13$ a CD-R, and you get to keep it forever.
well i know that the specs claim for many many more rewrites that 30 or 40.
but I am also amazed that you have even actually used any of your discs that much. I would expect that if your using the CDs that much - they'd get scratched up and ruined long before you killed them via to much burning.
I know that all my CDs are treated as a trash commodity that i just toss out when it starts getting bad. or I pre-emptively burn another copy of anything that is getting a lot of use - and throw out the other when its scratched up enough.
How much watching do you do to get 30 or 40 burns on a single RW?
You should take a look at the GNU version of TiVo called GnuVo. It's pretty nice except it won't let you watch any shows about capitalism.
A good place to learn how to convert various media to burnable (S)VCD format can be found at http://www.vcdhelp.com
Anyone examined a magnetic video tape's quality after 30-40, let alone 1000 rewrites? It's not too great either.
There's 10 types of people in this world, those who understand binary and those who don't.
I don't doubt the quoted figures of "1000 rewrites" for CD-RW media, for the reason that the crystalline substrate which stores the data proper should last around that much, chemically. In my experience, it's the physical disc which fails- scratches from handling, pitting on the reflective aluminum layer, etc.
CD-RWs reflect around 25% of the read laser, as opposed to CD-Rs which reflect around 75%, and pressed CDs which reflect close to 100%. When the signal-to-noise ratio is this low, the A/D circuitry has a hard time keeping up even with minor defects- fingerprints and dust are much more deadly on a CD-RW than on a CD-R.
In my experience, the first burn to a virgin CD-RW delivers CD-R-like readability, but once you rewrite it even once, the drive has to work a lot harder. I used to treat my CD-RWs like floppies, carrying them between the lab and my home, playing with them while waiting for an operation to complete, etc. and got maybe 4-5 rewrites on average. I then started keeping them inside jewel cases at all times, exposing them for a few seconds to put into the drive, and immediately got 20+ rewrites out of them.
Also, we were using really bad drives at the lab (some early HP CD-RW burners which often rejected discs) and when we upgraded the machines (to better HP burners, in late 2001) rewritability literally doubled for me to about 40+ rewrites. So the type of drive makes a difference as well IMHO.
Wrists killing you? Not in 2 weeks. Learn Dvorak.
Prices vary a lot, but there's often a sale for $7 per 50 CD-Rs.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
most of the CDRWs I've tried only last about 30-40 rewrites before they start showing significant data dropouts (almost always at the start of a recording)
Sounds like you've reproduced the VHS experience accurately.
Karma: Good (despite my invention of the Karma: sig)
how many rewrites do most people expect from their CDRW media
Zero. Actually, I find that CDRW are actually CDW. I can write to them, but I never expect to be able to read back from them. I've tried on dozens of CDRW drives, and I've never had luck archiving for a month or more on CDRW. Sure, "most" of the time it works - but it falls far short of my expected success ratios.
I've learned not to trust CDRW. I always use CDR instead.
Education is the silver bullet.
In the past 5 years since I puschased a DVD player, I have watched a VCR tape on average 3 times a year. Mostly becasue corporate videos came to me that way, and of course Lucas.
In the past years since I purchased TiVo, I have never recorded a tape, unless I was lo-teching for an unfortunate friend.
I still think that CD-R's are a more reliable medium, and still, in most cases a faster medium. But if you get right to it, what happens when you recorded a video on a tape, over and over and over. Or watched the same tape over and over and over, the picture quality gets worse and worse.
Phillips is now selling a DVD-RW for such purposes, so It does look like the video tape has one more nail in it's coffin.
To make a TiVo clone would be cool, but to make one that will output to CD's, CDRW's, or DVD's would be great. (But still it's a waste of time to dupe a DVD if you can't get DTS ot Dolby Digital on it...)
"This is you left and that's your left. This is your right and that's your right. You're gonna die!
The one exception I can see to this is if you're using the CD as a data transport mechanism, between your PC in the office with the fast data connection and your DVD player in the living room.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
Unless your device supports capturing of original closed captioning information onto the CD-RW's - meaning you preserve the information present including the stuff in the vertical blank interval and replay it on playback - you will never be allowed to bring this device to market as a consumer VCR replacement. As far as I know the SVCD format does not have any built in mechanism for this. There are certain things you need to do to meet FCC requirements before this device will be allowed to be sold in the USA market. Same rules applies to closed captioning decoders being required in all TV's 13" or larger.
Ah, but there really is a TiVo clone in the works: FreeVo.
The roots of education are bitter, but the fruit is sweet.
--Aristotle
Best Buy sells 100-paks of Memorex for $30, with a $20 rebate. I've successfully gotten all my rebates back in 1.5 months.
That comes to $5 for 50.
And yes, I've written and pointed this out to my reps. :-)
When companies talk about MTBF, or number of re-writes, or anything like that you have to remember these few rules:
1. They were done under ideal conditions and not your normal, everyday, household conditions.
2. They count every time they were actually able to do whatever. (Like in being able to write to the CDRW disk they will count even partial writes in order to boost their numbers.)
3. They don't care if they make outrageous statements. It takes a very long time to prove them otherwise. (Take the cigarette industry - PLEASE! Look how long it's taken to prove them wrong. [And they are STILL fighting it in the courts.])
It used to be that if you cut whatever the company said in half you could be close to what the actual figures were. Now it's about a tenth of what they say. Not that all companies are like this. But there are quite a few.
Someone put a black hole in my pocket and now I'm broke.
Wow... amazing how people don't get it.
If it's on a CD in SVCD format then you can take it to nearly any DVD player, stick it in, and watch. That's it.
If you're limited to a computer then you're paying 4-10x the money for the playback device and you can't transport it. Want to record something for someone else, or to take to a friend's house and watch? Too bad. Want to send a recording of an important TV show to family or friends? Nope. Can't do.
Not to mention that labeling a CD as "Junkyard Wars, Season 5, Episode 3" makes it a whole lot easier for a non-techie to deal with than some obscure location on a poorly integrated HTPC.
I built a similar system myself, basicly a tivo built out of a shuttle SS51G and a all-in-wonder. The problem I've foud is that the CDRW is just too small to replace a VHS. A MPG and standrard VCD quality is about 600 MB per hour, so a CDRW only holds an hour of TV per CD. Thats great for 1 hour long show but it doesn't work too well when you want to store a movie or a longer show. Also I mainly store serries of shows (like star trek) , its far better to have a dvd+r with several episodes of the same show then have to swap through many cds.
I don't bother with CD-RW, I just use CDR. I only buy them when they're "free after rebate," which between OfficeMax, Staples, BestBuy, and Compusa, is about every other week.
Here are my notes about how I made one disc:
I wondered if I got some quality degradation by exporting from MA in motion-JPEG format, rather than keeping it in native DV format, and then encoding to MPEG. Ideally some of the JPEG frames would just directly become keyframes in the MPEG output; but in this case I was scaling too, so that's not possible. Anyway most of the output formats in MainActor for Linux have bugs, and MJPEG happened to work well.
I didn't go with (S)VCDs because my DVD player (XBox, actually) doesn't play them.
The cost of entry is higher, but the quality is far superior than VHS (unless you're trying to record off of the local Fox station, but that's their fault).
Boobies never hurt anyone. - Sherry Glaser.
Last year, I've written my thesis work about recording VCDs in real time. I have a simple command line tool you can run to record analog TV (with small changes probably from any source) to your CD writer. The code is GPL, based on VCDImager and somewhere in the VCDImager repository.
The thesis text is a bit dated by now but you can still find it at http://users.evitech.fi/~arndb/project/htmlmain/
Arnd Bergmann
VHS has a ton of analog noise. This means that you'll need to encode the digital copy at a substantially higher data rate to get the same effective quality, and you'll have a pretty low ceiling on maximum quality.
The difference between even S-VHS and VHS is huge.
So, grabbing off DVD or straight from a high-bitrate PVR would be quite a bit better. And if you have to go through analog, make sure you're capturing via S-Video instead of composite. Otherwise areas of saturated color will get that annoying cross-hatching effect. It's isn't so noticible on TV, but man is it obvious on a computer monitor!
My video compression blog
I'm the guy who posted the story and I'm documenting my experiences and the project at aardvark.co.nz/pvr/.
:-)
What you say has some merit -- SVCD is certainly streets ahead of VCD in terms of image quality.
However, DivX is not quite the ogre you make it out to be.
For a start, it takes no more CPU to encode DivX format as it does to do a *good* job of multi-pass MPEG encoding.
On a 1.8GHz P4, TMPGenc takes around 6-8 hours to encode a 100 minute movie into an MPEG2 file to SVCD standards using multipass variable-bit-rate encoding.
You can get faster multi-pass MPEG2 encoders but they are *expensive* -- TMPGEnc is free for MPEG1 encoding and costs (from memory) just $49 for the version with MPEG2 capabilities.
By comparison, the same machine usually does a multi-pass DivX encoding in just a fraction that time.
In respect to playback, the DivX codec is quite nice insomuch as it allows some optimizations and post-processing to be performed as the video is played. This means you can create a video file that is able to be played back on a variety of different machines with different CPU-powers -- such that the faster machine will produce a better result but the slower machine will still play without pauses or stuttering.
In the past couple of months I've downloaded and evaluated hundreds of MB of applications, drivers, documentation, etc for all manner of commercial and freeware PVR solutions. These will all be compared on my site shortly.
I'm also about to publish my findings on the Haupaugge PVR card which does hardware-based MPEG1 and MPEG2 encoding -- thus freeing up the PC's CPU and allowing more "headroom". This is important when you're trying to do things such as timeshift or concurrent record/playback.
Linux-based software solutions are also being evaluated but unfortunately (damn it!) there are only two or three that appear to have much merit.
Given Microsoft's agenda to hog-tie all video and audio with DRM I'd really like to come up with a Linux based (and preferably OSS) option that is reliable, functional and ergonomic.
The truth will (eventually) be revealed
Try this link.
;-)
I'm planning to update the site with all my latest findings later this week -- including a review of a Haupaugge tuner/capture card that has onboard hardware MPEG1/MPEG2 encoding.
Linux-based options are also being reviewed as I type this
Why are you using re-writes at all? You can get a spindle of CDR's nowadays for $16.00 CDN on sale. (Must be $10 US?) That's 10 cents a disc, and you get to *keep* them. You are meanwhile spending 2.50 on a CDRW that you say can only be burnt 30 times, or 8.3 cents a burn. Seems to be it just isn't economical at all, when you could be spending pretty much the exact same amount and archiving all yoru movies instead of wiping them.
What I like most about this question is premise must strike fear in the hearts of the MPAA and other big media goons that are reading it. The premise is a recipe for a p2p video experience. The MPAA and the perpetrators of the DTV fiasco are hoping to eke out some more life for themselves by trying to convince people they need better quality and they want to pay more money for it, oh, ignore the chains that come with it.
But your question demonstrates that you don't value what those hucksters are trying to sell you, you want flexibility. And it just so happens that flexibility means you can download video in a reasonable amount of time and store it on cheap media, ala mp3.
I had a Dr Who hankering the other day, hadn't watched it in years. I don't own a TV, I probably watch a sitcom every 3 months or so and am blown away by the crap on TV, I've never been in a household with cable. I downloaded maybe 15 vhs-ish quality Dr Who episodes as divx over a couple nights and watched them over the course of a week, haven't felt the need to watch them or other movies since. Now that's an experience that big media has no interest in providing me.