Talk:Blu-ray

405nm blue-violet laser for BD/HD-DVD

For me this sounds rather redicolous. As far as I know blue semiconductor lasers have a life cycle around 1000 hours. In case you are very lucky. BD and HDDVD players utilises light source known as laser diode. It allows to increase lifetime of source greatly - up to 15000 hours. If anyone seen yellow mark with "Class I laser product" on your BD/HD DVD player please report. I have no such things on PS3 Vadim Mayorov 14:14, 9 June 2007 (UTC)

Dolby Digital Plus Bitrate

I believe the maximum bitrate for Dolby Digital Plus audio on Blu-ray is 4,7mbits instead of 1,7. Blu-ray specs allow for a 640kbits Dolby Digital packet plus up to 4 packets of 1 mbit DD+ audio.

No, the current spec only allows for one extension packet for a total of 1.7mbit/s see the references on the Dolby digital plus page for details. --Ray andrew 22:04, 8 May 2007 (UTC)

Blu-ray Disc – HD DVD comparison (chart)

Mentioning single layer and dual layer capacity HD DVDs and Bluray discs is OK. We have established that Bluray has ~66% more data storage capacity than it's HD DVD counter part. However, mentioning triple and quadruple layer discs are unnecessary and possibly misleading. Information on more then dual-layer should be removed removed from the chart and possibly be put in its own section. Non-technical people may brag about 200GB being greater than 15GB, despite that more than 2 layers will most likely never be used for commercial or mass-market purposes, as with DVD. In addition, technical people who may in some way understand this data don't need a comparison chart to tell them that a 3 layer disc has three times the capacity.

Basicly, what I'm saying is, No shit, Sherlock Can Not 02:45, 26 December 2006 (UTC)

What if they are used? Mbslrm 05:14, 26 December 2006 (UTC)

It would still be redundant. A sentance or 2 could cover it, but it serves no purpose in the chart, other than misleading the ignorant. --Can Not 04:48, 28 December 2006 (UTC)

I agree with Can Not. These quadruple-layer discs aren't in the spec, so they aren't Blu-Ray discs. Why not have a column for a 50 GB CD-ROM? You don't think 50GB will fit on a CD-ROM? All you have to do is make the marks smaller, make the cover layer thinner, add another data layer, and read it with a 405nm laser through a 0.85 NA lens. At what point does that cease to be a CD? Spiel496 05:48, 28 December 2006 (UTC)

I just checked to see if there was any objections. Glad to see it's already removed. --216.186.219.99 00:28, 16 January 2007 (UTC)

8 cm?

What does the "8 cm" mean in the "Physical Format" table? Could someone clarify for me what it exactly is? Is it another kind of Blu-ray disc or is it just for comparison? --Chaz 20:11, 26 December 2006 (UTC)

The 8 cm size for a Blu-ray disc would look like a Gamecube game disc. Its a actually a standard size that has been applied to Compact Disc and DVD.--Kenn Caesius 22:47, 26 December 2006 (UTC)

update links in wikipedia

Could someone update the link to this page in artical "gigabyte", there is a HD-dvd link needin some edit too... —The preceding unsigned comment was added by 66.129.130.216 (talk) 18:33, 1 January 2007 (UTC).

Question about rom-mark

"The Blu-ray Disc Association intends to ensure that only disks that contain the ROM Mark will be playable on Blu-ray systems. The ROM-Mark is expected to prevent the casual copy from BD-ROM to recordable media. It is a mechanism aimed to protect against bit-by-bit data copy. The ROM-Mark requires a special machinery in the disc mastering process in order to be inserted on disc and thus, it prevents malicious replications."

That's from this article and the ROM-Mark article. I'm assuming home videos will be allowed to play, so how are they getting around the ROM-MARK? Maybe someone can clear that up in these articles?

Mandatory audio support

I believe the table is wrong, TrueHD is not a mandatory codec for blu ray. —The preceding unsigned comment was added by 65.31.193.187 (talk) 05:19, 16 January 2007 (UTC).

What is 3X DVD ROM ?

It is mentioned in the comparison table. Nowhere else in the article does the string "3X" appear. xerces8 --90.157.129.176 14:16, 21 January 2007 (UTC)

• I wanted to ask exactly the same question... someone please tell us...:) 86.120.236.174 20:13, 23 January 2007 (UTC)

3X DVD-ROM is explained here...[1] This page is a Googleified HTML version of a pdf document. Scroll down to where it says "page 4" on the left.J.delanoy 17:18, 24 January 2007 (UTC)

Any plans on using this with Blu-Ray?--64.240.163.221 04:13, 4 February 2007 (UTC)

Not that I know of. From the article I gathered that they were just trying to kick a DVD up to HD standard without manufacturing a new technology. So my guess would be that they will eventually go down the same path as CRT television sets are: the techonolgy works, but it is outdated.J.delanoy 03:18, 5 February 2007 (UTC)

Kernel drivers

Will Blu-Ray use the same Linux kernel drivers as CD and DVD? What filesystem does it use by default? —The preceding unsigned comment was added by 65.188.253.13 (talk) 20:09, 22 January 2007 (UTC).

Comparison with HD DVD

In the "overview" section, the article spends a lot of time comparing blu-ray to HD DVD. In the HD DVD article, almost nothing is said about blu-ray besides mentioning that they are currently in a format war. If someone wants to know which standard is poised to win, they should draw their conclusion for themselves based on what they read about each format.(releases, support, sales, etc.) I think the first part of this article needs to be rewritten, but I want to see what other people think before I just lay into it. J.delanoy 17:10, 24 January 2007 (UTC)

==it seems that Blu-ray is for the win, and is outselling HD-DVD by a margin of 9:2 [2] 66.98.94.171 15:06, 13 April 2007 (UTC)

The Blu-ray movie experience?

I would like to see this article address the Blu-ray movie experience in a bit more depth than is given in the Java section. A suggested tack could be a comparison between it and the DVD movie experience since a majority of readers could readily use the DVD movie experience as a point of reference. 66.64.203.126 21:43, 24 January 2007 (UTC)

Remove 3x DVD from comparison table

It should go, it is not a competing format, its just what you get when you put hd dvd formated data on a dvd. If no one objects I will remove it. —The preceding unsigned comment was added by Ray andrew (talk • contribs) 19:15, 5 February 2007 (UTC).

Dolby Digital Plus is not a mandatory codec for Blu ray

I have seen this added to the table too many times, please stop. Dolby Digital Plus is NOT a mandatory codec for Blu ray. I will continue to revert any BS. Ray andrew 15:39, 18 February 2007 (UTC)

• Sorry for the addition Ray, and thanks for the informational correction. Do you think it should be noted at the bottom of the table that DDS is not a mandatory codec, such that people don't make the same mistake? Oh, and in reply to your comment on the history page im not a PR for FOX, just in case you were wondering. Cheers. hemant tailor 16:39, 18 Feb 2007

Copy Protection

I see nothing here about the Movie Ice age 2, which i believe is the first movie to be cracked from the blu ray disc format with the dvd menus and eveything, and it is listed on the private tracker of Bit-dvd.com, if anyone is a member than you can confirm it.70.50.63.24 21:09, 19 February 2007 (UTC)

Graffitti removed

--Robin Roberts 07:36, 25 February 2007 (UTC)

Blu-ray region codes

Are the three region codes 1,2,3 correct? On the back of PS3 games over here in New Zealand there is a number 4 which would make perfect sense if it were DVDs but there Blu-ray discs. It seems like they are using the same region encoding as DVDs. —The preceding unsigned comment was added by 125.236.182.226 (talk) 04:10, 5 March 2007 (UTC).

HD DVD / Blu-ray comparison

Hi. First of all, the numbers in the article is not up to date. Why don't u count them your self Ray? Second, these discs isn't representing all BD, and are therefor twisted facts, nether HD DVD. A better way to backup these numbers is to go to ex. http://www.blu-ray.com/movies/ and count them there. The site listing ALL movies, and the size of the disc. This is not a forum for the format war so please keep wrong facts out of it. --85.228.237.186 10:08, 15 March 2007 (UTC)

Needs Disc Photo

This article needs a photo of an actual Blu-Ray disc. Cribcage 15:30, 15 March 2007 (UTC)

Profile 1.1 mandatory date

Can someone please post a reference link for the 1.1 mandatory date? I can't find one for the july 2007 date much less the pushed back november 2007 date. Isnt 2.0 supposed to be out in november 2007. some kind of link would be nice.

Scratch resistant: Baloney!!!!

I would like to say to the person who changed what I wrote about the DVD abrasion cleaners not be able to scratch the so-called scratch resistant surface that he is only listening to the makers propaganda. First let me explain: Current generation DVD's can easily be cleaned of nearly all scratches by using an abrasion cleaner.(CD's and DVD's can also be cleaned of some minor scratches by those chemicals you can buy yourself in stores, but they don't work very well.) Abrasion cleaners are the machines some video game stores and rental shops use to clean DVD's of deep scratches. They literally take off a layer of plastic (by scraping the surface with a mild sort of sandpaper) in order to take out the scratch. They can fix nearly all scratched DVD's. On Blu Ray Discs, the data layer is much too close to the surface. DVD ABRASION CLEANERS DO TAKE OFF THE ENTIRE DATA LAYER ON THESE BLU RAY DISCS EXPOSING THE CENTER REFLECTION LAYER, thus permanently destroying the disc. I know because I have seen it done. Now let me use some logic here. OBVIOUSLY, there already was a deep scratch in this disc (Resistance: Fall of Man), and it would not play. That's why someone tried to clean it. Maybe, you say, it didn't have the scratch resistant layer on it. Maybe, but I don't believe so. AGAIN, just because they say it is "scratch resistant" and some joker puts a steel wool video on You Tube that makes it so? This scratch "resistant" layer won't degrade or wear off? I bet they're saying it'll last 50 Years (remember when they said that about DVD's?) I'm betting that these blue ray discs (even with the "scratch resistant" layer) will be about as long lasting as chewing gum. And at 60 to 70 bucks per game, it's a true con game. But then it's all a plus for Sony, because they've finally found a way to "SCRATCH" out the used market!!! Sony must be learning from Microsoft since they've managed to make a defective product that guarantees them more future income. YEEE HAAWWW!!

hence the word resistant. they only said it was resistant to scratches. it is like bullet resistant glass, while they show it can take multiple hits to different locations, multiple hits to one location would probably make a hole. the same applies here, if enough effort is applied to one area, it would be quite easy to make a destructive scratch. --Alphamone 06:42, 6 June 2007 (UTC)

Scratch resistant: not so much Baloney!!!

who uses those chemicals to clean DVD's at home? with scratch resistant they mean nails/keys screw drivers etc not chemicals since they don't cause scratches but change the structure of the material.

Who said anything about chemicals? --Ray andrew 00:48, 28 March 2007 (UTC)

what are: ABRASION CLEANERS?

Profile 1.1 makes 1.0 players obsolete

The use of the word obsolete is inappropriate here. The 1.1 profile no more makes 1.0 players obsolete than does the release of an Xbox 360 with HDMI support make the current Xbox 360 obsolete. Profile 1.0 players will still play the vast majority of content, including the primary feature (the movie). The ability to play back features reliant on secondary video in no way defines the overall value proposition of the Blu-ray Disc platform. Talkstr8t 00:08, 3 April 2007 (UTC)

Talkstr8t, I am assuming that you are the same Blu-ray insider (working for some secret company) that posts at AVS forum under the same name. If that is the case, I should remind you of the Wikipedia conflict of interest policy. I think the use of the word obsolete is appropriate. If you read the wiki on it one of the definitions is "when a new, more functional product or technology supersedes the old", and this is definitely the case here. I also would like to dispute the assertion you added a while back that some players could be upgradeable by firmware to 1.1, as no current player (besides the PS3) has the appropriate hardware to do dual stream decoding. I will leave profile section as it is for a few days to see if anyone else wants to chime in, but after that if there are no objections I will change it back. --Ray andrew 00:54, 3 April 2007 (UTC)

Ray, your HD DVD edits have consistently been biased toward painting that format in a better light, while your Blu-ray edits have painted it in a more negative light, suggesting a bias which would bring into question a conflict of interest on your part. I obviously have no problem with my edits being subject to community review.

My edit regarding "obsolete" takes a far more objective stance than the original text. The Wiki page on "obsolete" lists five definitions for technical or functional obsolescence. Four of the five clearly do not apply. The subset of text you quoted ignores the examples given, all of which demonstrate a change in format, not a change in feature within a format. By your very narrow definition virtually every CE product on the market today would be considered obsolete due to newer products with additional features. Does HDTV make standard def TV obsolete? Does the Video Ipod make non-video Ipods obsolete? Do mobile phones with Bluetooth make those without obsolete? Obviously not - all of the earlier products continue to perform the primary function for which it was intended, and continue to be developed, marketed, and sold. The ability of a profile 1.1 player to support secondary video in no way obsoletes the dominant feature of the format, playing back a feature title with high definition audio/video.

Regarding upgradeability to 1.1, both the PS3 and the now-released Samsung BDP-1200 are based on hardware capable of supporting profile 1.1 secondary video. Talkstr8t 20:07, 3 April 2007 (UTC)

So will you address the question about your conflict of interest? Do you admit that you are a Blu-ray insider? Will you disclose your employer (I know you wont but I had to ask)? If you have no problem with being subject to review then you should suggest the edits on the talk page first to avoid potential conflicts of interest. As to your concerns about me, my contrib log speaks for itself. I revert BS, and make useful contributions to both articles.

Sorry I did not know that the new Samsung had bee released (after all the delays), and yes I see that it uses a new decoder chip. It still doesn't change the fact that that the other players (besides PS3) will not be upgradeable. Maybe the Samsung should be referenced specifically.--Ray andrew 00:15, 4 April 2007 (UTC)

Yes, I'm an insider. That also means I'm a subject matter expert here. I haven't contributed extensively to Wikipedia, so I apologize that I'm unaware of proper etiquette regarding process for making changes. As I said, however, the word "obsolete" is purely subjective in this context and isn't appropriate here.

The Samsung wasn't delayed; it was originally announced at CES for April, and made it easily.Talkstr8t 02:08, 4 April 2007 (UTC)

Profile 1.1 will not make 1.0 obsolete. The blu-ray discs which have PiP will make them "obsolete," if that is the term you want to use. Profile 1.0 players will still be able to play Blu-ray movies, but they will not be able to take advantage of all of the extra features, ie. the IME (Interactive Movie Experience). So obsolete is correct in that they will be out-dated, but not unable to be used to watch new releases after Profile 1.1 becomes mandatory. They will be like the PS2 or Xbox after Sony and Microsoft, respectively, came out with their next-gen systems. Games were still made for both systems (look at God of War II), but the more advanced systems were, of course, the newer ones. By the way, I'm format neutral; you just need to clarify how you are using the word. By house_n

This comment hugely overstates the significance of the Profile 1.1 additions. Out of all the interactivity which has been shown across dozens of discs of both Blu-ray Disc and HD DVD, the only feature which profile 1.0 players won't support is PiP as implemented by secondary video. This is nothing like comparing PS2 to PS3, where an entirely different hardware and software platform is provided.Talkstr8t 15:01, 4 April 2007 (UTC)

Not quite, theres also the question of real time audio mixing, (ie, mixing in the commentary track to the original, etc). Also both camps have demonstrated interactive features that require an Internet connection, profile 1.1 definitely cant do that ;) (all HD DVD players and profile 2.0 Blu-ray players can). But still this is a large amount of the "next gen" interactivity here that profile 1.0 players just cant do (playing static Java games is so last gen).--Ray andrew 12:56, 5 April 2007 (UTC)

It doesn't really matter what word is used as long as the article clearly states that upon the release of profile 1.1 systems. That the functionality of all previous profile 1.0 systems will be substantially less then current models that are available and unable to utilize the full functionality of future discs. a very limited amount "may" be upgradable but most just do not have the hardware installed.. to me a 1.0 system is more like a beta test that people paid 1200 to be part of... with profile 2.0 being the actual real "standard" to come.. and in my opinion will obselete both profiles in the long run. leaving 1.0 players with the equivilent of a low end no frills dvd (sorry I mean blu-ray) player...call it obsolete call it limited functionality.. whatever. At ces blu-ray was not showing off the wonderful features of blu-ray.. they were showing off the wonderful features of blu-ray...2.0. Im not anti blu-ray and if anything I think the tech is better (storage ect..)... as for Ray supporting hd-dvd. we all have our preferences. all his edits seemed to me to be accurate and timely.. he deletes bogus anti-bluray info as well. keep up the good work Ray. 71.107.48.182

I am a Network Engineer and part-time sales person at Tweeter. Talkstr8t is correct. The word obsolete in this case is misleading to people. They might think their Blu-ray player will not be able to play future Blu-ray discs. This, of course, is not true. This should be corrected. This will make Wikipedia lose credibility in the eye of the users if this persists. This issue has been made known on several forums.Ascended_Saiyan24.99.191.203 02:31, 5 April 2007 (UTC)

For the record the removed wording was: "It is possible that some profile 1.0 players may be upgradeable via firmware update to profile 1.1. However any player that is not upgradeable will be considered obsolete after November 2007, when profile 1.1 becomes mandatory, since they will be unable to handle all interactive features that new discs released after this date will contain. They will still however be able to play the main feature of the disc as they do now." So I don't think it could mislead people to thinking what you are saying. As to the credibility of wikipedia, I personally think it would be improper to downplay this. Because it is really something that every person looking to buy a Blu-ray player should be aware of. --Ray andrew 12:56, 5 April 2007 (UTC)

There are still a couple of issues I have with the sentence "However any player that is not upgradeable will be considered obsolete after November 2007, when profile 1.1 becomes mandatory, since they will be unable to handle all interactive features that new discs released after this date will contain." Even though new player models released after Oct 31st must conform to the BD-Video "1.1" profile (note that the spec never actually refers to a 1.1 profile), there is no requirement that content will, and in fact it's unlikely much content will be released supporting the new features until a number of players are in the market. Further, looking at the full library of HD DVD titles, only something on the order of 10-15% of them actually feature content which makes use of features introduced by BD-Video 1.1 (i.e. secondary video), even though all HD DVD players are capable of supporting them. From this data one can reasonably surmise that only a minority of future Blu-ray titles will make use of these features (i.e. high-profile titles), especially given the production costs required to support such content, which further dilutes the notion that current Blu-ray players will be "obsoleted" by the "BD-Video 1.1" profile.

Regarding realtime audio mixing, currently available players must support several levels of realtime audio mixing. "Profile 1.1" players must support a greater number of channels and secondary audio. It's also possible that existing players fully support secondary audio, as the current chipsets are fully capable of doing so.

Ray, you've apparently been a stickler in your Wikipedia edits for factual, objective information. The word "obsolete" is not only pejorative, but purely subjective. One consumer's definition of what makes a player obsolete will clearly differ from the next, and for the foreseeable future the overwhelming majority of available content (i.e. all existing titles, all future main features, most future bonus features) will be strictly unaffected when played back on "Profile 1.0" players, and even for that content which does rely on "Profile 1.1" features much of it will be downgraded (i.e. audio but no video) rather than unavailable. The use of the word "obsolete" here clearly degrades the quality of this article.

I will concede that 'obsolete' may be a bit strong, but I still feel that the current article may paint an unrealistic picture of the future prospects of current 1.0 players. Also I was under the impression that current Blu-ray players did not support any real-time audio mixing (ie mixing two streams together), could you give further information about this. --Ray andrew 04:10, 6 April 2007 (UTC)

I can't copy from the spec verbatim since it's only available under license, but if you have access to the spec you'll find details in section 8.10 of BD-ROM Part 3: Audio Visual Basic Specifications (3-1 Core Specifications). Interactive audio, primary audio, and secondary audio are defined. Secondary audio is optional in 1G players, but mixer support for primary and interactive audio must be provided. If it weren't supported you wouldn't hear button and other menu sounds.Talkstr8t 07:46, 6 April 2007 (UTC)

Amount of 50 gig releases on par with 25 gig

I added up the releases in the last 90 days and it seems there has been 35 25gig and 39 50gig releases. so its right around 50/50. the previous statement that 25gig is far more preferred by devlopers seems no longer accurate. the outlook on new releases looks about the same. Does anyone disagree? If you want to add in all the 25gig releases since blu-ray came out sure you come up with more. I think 90 days is a fair amount of time to go by and Its possible that since the first releases were in november for 50 gigs alot of the projects in the works were still based on the 25gig discs slowing the ramp up a bit. any thoughts? 71.107.48.182 05:30, 7 April 2007 (UTC)

Explanations needed

1) What is PIP? 2) What is the significance of Region codes? Kdammers 02:44, 12 April 2007 (UTC)

New Compare table discussion

Hi all. We are discussing a new Compare table. Please come in and leave your opinion on the new tables here. --StarChild74 13:38, 17 April 2007 (UTC)

Hard-coating technology

"Nonetheless, if a scratch does occur, there is no current way of removing the scratch without causing further irreparable damage. Abrasion cleaners used in video game stores to clean DVD game discs and movies (by removing plastic and thus the scratch) will not work. This is because the data layer is so close to the surface that even if the abrasion cleaner was able to remove the scratch, it would also remove the data layer destroying the disc."

Does someone have a link of a reliable test that confirms this? Until then I see this as speculation. Ray Andrew say that it is fact. So I guess that you have some proof to show that then, as you know that it's fact? The last part is even written as speculations; '"...close to the surface that even if the abrasion cleaner was able to remove the scratch...". My personal believes is that this is right information, bocouse it sounds right, but should this wiki base on persons believes and speculation? If this is right, then it should be a test somewhere. Until then I will continue deleting this part. And when someone comes up with some reliable proof I gladly put it back myself. --StarChild74 08:01, 18 April 2007 (UTC)

If everything in this article had to have good references, we would not have an article. So if you think its true, then why don't you assume good faith and just tag it {{cn}}. --Ray andrew 12:59, 18 April 2007 (UTC)

That section doesn't contain any relevant information to the article. Does any other consumer product include a section that basically says "It is possible for the owner to damage this product beyond repair." Every product you could ever buy can be damaged beyond repair. Laserdiscs can be scratched beyond repair, CD's can be scratched beyond repair, DVD's can be scratched beyond repair, HD-DVD's can be scratched beyond repair. Heck even your car can be scratched beyond repair (yes a collision with a brick wall at 50mph could be considered a scratch). Why does blueray need a special section about scratches? Just like CD's, DVD's and HD-DVD's, Blueray includes robust EEC algorithms to protect against scratches ruining the disc.The Goat 15:14, 18 April 2007 (UTC)

You don't think its relevant that unlike CD's and DVD's scratches cannot be repaired? I would consider that relevant information, as it is an important difference from the technology that it is seeking to replace. ECC is nothing new either and it can only do so much. --Ray andrew 15:22, 18 April 2007 (UTC)

So you, Ray andrew, basicly say that it is free to anyone to just put something in articles without any backup and then it's not okey to delete it. Shouldn't it be the one who wrote it that going to have some proof. Thats something new for me. --StarChild74 15:41, 18 April 2007 (UTC)

Don't let your inner fanboy bias your editing. If you dispute the facts then do so, if not then answer the question: Do you think its relevant that unlike CD's and DVD's scratches cannot be repaired? --Ray andrew 15:53, 18 April 2007 (UTC)

Ray there is no difference with scratches on CD's/DVD's and scratches on Blueray discs. Shallow CD/DVD scratches can repaired. Deep CD/DVD scratches can not be repaired. How is that any different to scratches on blueray discs? Are you claiming that any scratch at all ruins a blueray disc? That is clearly not the case. Unless you can show an actual study that has some evidence that blueray discs are ruined by scratches at a significantly higher rate then CD's and DVD's I will continue to remove this section from the article. CD's are much easier to ruin with unrepairable scratches. Scratching the label side of a CD can leave the disc unusable with no hope of repair. That is much easier to do then scratching a blueray disc.The Goat 18:01, 18 April 2007 (UTC)

I think I would go with removing the wording. only because I don't think 99% of the population has a home DVD repair kit in thier home. Most I bet just buy a new dvd. If I added up the number of dvd's and cd's I had that are now coasters due to scratches (which I had to re-buy) I would be pretty pissed. the whole "virtually indestructable" line when we switched from cassettes was a riot.. lets not do anything to make that format look any better then it really is..lol You scratch a cd or dvd its just as useless if you don't have a repair kit and if you do have one (at an extra expense I might add) then it "may" work after repairing it but it prob wont a second time.. At least blu-ray added a hardcoating.. and one that seems fairly robust and stands up to quite a bit of abuse.. I give them that much (the hardcoating IS thier abrasion cleaner by preventing as much as possible before they happen. some scratches on dvd's are just too deep to be fixed as well.). I mean if you take the pizza cutter and steel wool to it then find out that doesnt break it so you decide to run over the disc with your car. sure you may need to buy a new one ;). seriously though.. if you don't take care of it.. it breaks.. seems pretty self explanatory to me. has anyone done a test on how different an HD DVD is to blu-ray in the scratch catagory? maybe we should add a note on that article that unlike blu-ray which has a protective coating and is not susceptiple to damage even from steel wool and pizza cutters, a slight scratch on your disk may render it useless causing you to need go out and purchase a home abrasian cleaner which may or may not work... thats just as bad I think. -71.107.48.182 18:40, 18 April 2007 (UTC)

Ray: I'm the fanboy? Thats something new to. It's obviously you who is the fanboy. You say: When we going to discuss "remove Hard-coating info" that are a minus to Blu-ray we don't need a source. But when we discuss "adding Sample frequency" in HighDefMediaComparison Table, that is a minus to HD DVD, then we need a source (as Blu-ray's white-paper weren't sufficient for you). So I wonder who's the fanboy around here, and I suggest that you think outside the box in the future. I try to be as neutral as possible when I write in this wiki. If I aren't you are welcome to notice me instead of just calling me a fanboy without any explanation. If that is the case I suggest we take that discussion in a PM as it don't belongs here. And for your notice I'm not convince to any of the two sides, I'm just allergic to unneutralized information and fanboys behaviour.

I suggests that we leave this information out of the wiki as we are tree against one. IF you can show us some reliable proof, I'm on your side! --StarChild74 19:01, 18 April 2007 (UTC)

You all are a tough crowd :). It looks like a quick Google search solves everything. From this information it looks like there two options, if its a light scratch (ie does not go through the 0.05mm hard coat) then buffing may be able to remove it without totally removing the hard coat. But if its bigger, then the whole hard coat must be removed (which they admit is dangerous as the data layer is so close), but then the disk has no protection and could easily be damaged. So a rewording is in order, but the topic is still relevant. I'm sorry if I offended anyone earlier, that was not my intent. --Ray andrew 19:42, 18 April 2007 (UTC)

Both of those sources you linked to actually say scratches on blueray discs are repairable with the current machines. They also state that early experiments show it is much more difficult to scratch a blueray disc then a CD/DVD. They also hypothesize that repairing a scratch will be more difficult on a blueray disc because of the thin plastic layer on top of the data layer. But they note there lack of experience in the subject when making this statement. There is no actual real world evidence either way yet. Blueray is too young to make a statement about its repairability. The article already makes a clear statement about the thin plastic layer over the data layer, and the possibility of scratches affecting the disc's data layer.The Goat 20:48, 18 April 2007 (UTC)

How is that at odds with the way I rewrote it: "However if the hard-coat is scratched it is harder to repair then other optical media. If the scratch does not penetrate the hard-coat (less then 0.05mm) then some of the hard-coat can be removed to repair the disk. If the scratch is deeper then the entire hard coat must be removed, leaving the disk vulnerable to further damage."??? This issue needs some mention, so If your going to take issue with my verbiage, you better come up with some replacement. --Ray andrew 21:01, 18 April 2007 (UTC)

ok... a few things. source one states they have not been able to repair to many because its very hard to find damaged discs in circulation (thats good for blu-ray)and that they were impressed at how difficult it was to actually damage the disc.. even when personally trying to. (I breathe on my dvd and its scratched) source 2 states that the coating gives them a "much better" scratch protection then dvd's (and I imagine hd dvd's as they are made the same). also according to the sources the scratches within the hardcoating come out with what amounts to a "good cleaning" with a buffing machine..the buffing process does not penetrate the hard coating they say...alot better then having to take sandpaper to the disc and prob less risky for light scratches. the hard coating only needs to be removed IF the scratch pentrates the hardcoating completly not even if it does not penetrate as the new verbage states. at that point...the disc will only THEN be as scratchable as easy as dvd's are. I think adding anything about the scratchability is unfair at this point until more data is avail. otherwise it appears we are just looking for a negative. and in fairness if we add something about the scratchability something really needs to be put on hd-dvd and dvd as to how blu-rays coating gives much better scratch protection compared to hd dvds - dvd's in everday use. otherwise we would be playing favorites. thats just my opinion.. maybe I read the article wrong. and remember these are companies who make a profit off fixing discs..not very good for them to be saying blu-ray is very scratch resistant. my guess is if they could they would be saying these things are very scratchy buy our product now to save your discs..... -71.107.48.182 01:18, 19 April 2007 (UTC)

The fact that hard-coated disks are harder to scratch is not contested. The hard-coat does its job admirably in that regard, however like everything it is not perfect. If a scratch occurs though, it does create problems with Blu-ray discs. Why? Well its the depth of the data layer, no the scratch probably wont be that deep, but none the less it is harder to focus around then on other disks (CD, DVD, HD DVD) because the beam spot on the disk is considerably smaller. This is in contrast to the other optical disks, where most small scratches can be focused around. This slack has to be picked up by the error correcting code.

Back to the topic, buffing a disk does remove a small (even if we are talking microns here it makes a difference) amount of the surface of the disk. That is what I stated in my rewrite "..some of the hard-coat can be removed..". I'm not just looking for negatives here, but hype needs to be balanced with reality. We need remember why a hard-coat is required (they had no choice besides cartages), and that in the case that it does get scratched it works differently then other discs. --Ray andrew 02:19, 19 April 2007 (UTC)

If anyones interested, there is a nice article with the differences in ECC between Blu-ray and HD DVD here. Warning: some knowledge of ECC is required. --Ray andrew 18:01, 19 April 2007 (UTC)

vulnerability to data loss due to scratches/wear

Let's see if I can summarize this.

Case 1: CDs have two different sides with respect to scratching. The label side and edge is only a lacquer layer away from the data layer. The other is some mm of polycarbonate away from the data layer. Same with CD-R and CD-RW, just a different kind of data layer. Exotic variations, such as double sided CDs are more like DVDs in that the data layer is not immediately under a very thin lacquer layer. So scratches to the label surface or edge are immediately dangerous (corrosion, moisture, ...) to the data stored on the disk. On the non-label surface, buffing/polishing, if done carefully can save many disks. On the label surface, this is not possible in practice as the lacquer layer is both thin and soft.

Case 2: All DVDs have a layer (thinner than in the case of ordinary CDs) of polycarbonate between the outside surface and the data layer. Except for the edges, where there is lacquer protection only. How thick the polycarbonate layer is depends on how many data layers or sides the DVD has. And like CDs, the nature of the data layer changes between pressed DVD and the field writable DVDs, but not the polycarbonate layer protection. So scratches to the edge are immediately dangerous (corrosion, moisture, ...) to the data stored on the disk. On both surfaces, buffing/polishing, if done carefully can save data on many scratched disks.

Case 3: The Blu-ray disc data layer is immediately under the reading surface (the non lable surface in most cases). In these, scratches on the label surface are much less dangerous to data, exactly the opposite of CDs. The protective hard surface layer makes scratches there less likely than for similar media. But harder to repair when present as the hard layer is quite thin, and more urgent since the data layer is so close to the surface and such scratches are more optically important than in CDs or DVDs. So scratches to the edge are immediately dangerous (corrosion, moisture, ...) to the data stored on the disk. On the reaading surface scratches are dangerous and less easily ignored, but harder to make given the hard surface layer. On the reading surface, buffing/polishing, if done very very carefully can save data on some scratched disks.

I think I've got the differences fairly covered. If so, and I'd appreciate a check or two by other editors, something like this info should be in the CD article, the DVD article, the Blu-ray and HD-DVD articles. The differences are relevant to WP as the Average Reader for whom we are writing/editing are not being educated about them, though understanding (and the differences) are important to protecting their data (eg, songs, movies, images, programs, ...). ww 11:08, 19 April 2007 (UTC)

The thin layer protecting the data on a blueray disc is already correctly addressed in the article. The major disagreement as I see it Ray wants to include a section about scratch repair machines being used on blueray discs. These scratch repair machines are not a major factor in the optical disc industry. Wikipedia doesn't even have an article about these scratch repair machines that I could find. Furthermore there is no real world evidence for repair attempts on blueray discs available yet. All optical discs (CD's, DVD's, HD-DVD's, BD's, etc.) have been designed to continue to operate correctly with scratches. What is unique about blueray in this respect? Blueray discs have a thiner protective layer on top of the data but they also have much stronger EEC protection then the other formats. Nobody knows how scratches will end up effecting blueray usage in the real world. If in the future there are reports of statistically higher numbers of blueray discs being ruined because of unrepairable scratches, then of course something should be added to the article. But now it is way too early to do so.The Goat 13:55, 19 April 2007 (UTC)

Wal-mart high-def disc rumor

There's a rumor Wal-Mart has requested 20M high-def disc players--some reports say HD-DVD players, but it's not clear; they may be Blu-Ray. I don't think there's anything verifiable enough to be added to an article yet. Discussed at more length at Talk:HD_DVD#Wal-mart_HD-DVD_rumor. 67.180.140.96 05:33, 22 April 2007 (UTC)

Regarding my rewrite of the DRM section

Tracer9999 undid my revision, saying "previous edit was fine. new edit adds less info".

That was precisely my intention, avoiding unnecessary duplication of content. Moving most of the AACS-specific parts to the relevant article. Then I expanded upon the parts that are Blu-ray specific.

What parts of the old revision (if any) do you think should be added to my version?

• BD+ is covered in my version of Blu-ray
• Mandatory Managed Copy is covered in my version of Blu-ray
• CSS vs. AACS is covered in AACS
• BD-ROM Mark is in my version of Blu-ray
• The analog restrictions / ICT is in AACS
• The "cracking" of AACS is covered in AACS

— Ksero 01:31, 4 May 2007 (UTC)

HITACHI announces 1000 GB Blu-Ray Recorder !!!

• [3] —The preceding unsigned comment was added by 201.79.53.234 (talk) 13:07, 11 May 2007 (UTC).

Focus on video storage

I believe this article has too much focus on commercial video discs rather than the physical medium itself. By reading the article it does not become clear which of the DRM restrictions apply to normal recorded data CDs and if its possible not to include DRM. ("The Blu-ray format employs several layers of DRM.")

-- 83.99.184.75 17:43, 12 May 2007 (UTC) (Not logged in: J7n)

BR is winning

Virgin Megastore Tower Records at Piccadilly Circus has 4 shelves of bluray and ONE of HDDVD. Bluray is winning. --81.105.251.160 13:25, 1 June 2007 (UTC)

• Same thing at my local Best Buy. Two weeks ago they rearranged the HDDVD/blueray sections. They doubled the blueray section and halved the HDDVD section. I think the retailers have already seen the future in their sales numbers.The Goat 14:35, 1 June 2007 (UTC)

This so called format war is quite irrelevant. Because of the heavily crippled nature of both medias and files contained on them, an user is required to rip both discs in order to safely backup and watch the video recordings without restrictions. The resulting ripped files can be stored anywhere and only their quality matters, and not on what physical disc they were released by the commercial publisher. 83.99.184.75 03:19, 7 June 2007 (UTC) (Not loggen in: J7n)

Obvious

In the section DRM, AnyDVD HD: "..but they will release no details for obvious reasons". Call me a fool, but I don't know what the obvious reasons are, nor do I want to sit and think it over for a while. --ScarletSpiderDavE 03:37, 8 June 2007 (UTC)

Paper Disc

I think it's time for the Blu-ray Disc#Paper based Blu-ray Disc section to go. The reference is three years old. I can't find any evidence that it's been commercialized. The motivation seems sort of weak: it's supposed to be environmentally friendly somehow, yet one could argue that a half-paper half-plastic disc would be difficult to recycle. I tried to find a diagram showing the structure, but failed. Does anyone object to dropping this section? Spiel496 04:22, 12 June 2007 (UTC)

Ditch it.The Goat 12:11, 18 June 2007 (UTC)

I notice that 64.128.200.78 added some good material on the disc structure. However, the reference is still three years old. Also, the more I think about it, the more lousy the idea seems to be. The motivations for moving away from polycarbonate are:

• Cost. However, CD-R discs are nearly all polycarbonate, and they are less than 1$ each.
• Recyclability. Can't polycarbonate be recycled?
• Less material. So what? Optical discs seem like a fairly small fraction

Spiel496 04:12, 19 June 2007 (UTC)