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You would think by now that the consumer electronics industry would have learned a few lessons about format battles… Apparently not because right now the leading names in home entertainment are getting themselves into a right old tizz over home video recording formats. It's mostly puff and posturing at the moment but if we are really unlucky they'll start slugging it out in the marketplace with real products and guess who'll be getting their fingers burnt?


We all know that VHS has had its day as a home video recording system and that waiting in the wings to take its place is a recordable version of the phenomenally successful digital versatile disc or DVD. What you may not know is that there are three very similar sounding format variants (there were five at one time…), and needless to say they're all incompatible with one another. But this time around it's not just a simple tussle between competing factions within the home entertainment industry, there's an added complication.


Recordable DVD is a what teccies like to call a cross-platform media, in other words it's not just for recording TV programmes and watching movies, it has many applications in computer data storage and software distribution. Clearly it would be very convenient for everyone if there were a single universal standard for both PC and video, but each of the parties involved have their own agendas. The stakes are very high – we're talking about lucrative patent rights and a massive world market worth billions of dollars – and positions have become deeply entrenched.


A solution is being sought and good sense may yet prevail -- it does sometimes -- but there is still an outside chance that the unthinkable will happen and two or more competing formats go head to head in the market in a serious way. Invariably in these situations there is only one winner and as usual we'll be the ones to pick up the tab!






Firstly our sincere apologies for all of the acronyms littering this piece but you can blame the protagonists for adopting such confusing designations for their technologies – come back names like VHS, Betamax and V2000, all is forgiven…


DVD-RW (DVD-Read/Write, and note the 'minus' sign) is one of the three recordable or 'writable' DVD formats endorsed by the powerful DVD Forum. This is the 'official' body established by a consortium of manufacturers and software companies to ratify, control and police the DVD specification. For the record the other two approved writable formats are DVD-R and DVD-RAM, (more about the latter in a moment).


DVD-RW is very closely related to DVD-R (DVD-Recordable), a little used and relatively obscure write-once recordable format, which in turn has strong family ties with recordable and re-writable CD (aka CD-R and CD-RW) formats. DVD-RW machines are now in the shops, albeit in very small quantities and at a highish price. First off the starting blocks was Pioneer, which tentatively launched a machine in Japan in December 1999, and has subsequently imported a few models into the UK. The company played a major part in the format's development and it has solid backing from most members of the Forum, though a couple of companies (notably Sony and Yamaha) are keeping their power dry and have interests in an alternative system, which we'll look at next.


Widely tipped as the one to succeed DVD-RW has an impressive specification and pedigree. Discs can hold up to 4.7Gb of data, or as much as existing DVD-Video discs (more than enough for a 2-hour movie). With certain provisos DVD-RW discs should be backwards compatible with existing DVD-Video players. The catch is that discs have to be 'finalised' to play on a DVD-Video player, and cannot thereafter be re-recorded without being erased. There is also a possibility that some older players and drives will run into trouble due to the disc's low reflectivity. This may cause some players to incorrectly treat DVD-RW discs as dual-layer recordings, however the problem should be relatively easy and inexpensive to resolve by updating the player's ''firmware' control software.


DVD-RW records data using the same phase-change system as CD-R/RW and there are close similarities in data and track layout. Discs are robust enough to be handled in the same was as audio CDs and DVD videos. Since there is nothing particularly radical about the technology this should translate to reasonably priced decks and blank discs. Many industry pundits agree that the price of late first generation players – i.e. within a year or so of a concerted launch by several manufacturers -- should quickly settle to around £600. In the same sort of timeframe blank discs should be selling for between £10 and £15, if and when the market is established, and fall quickly thereafter to levels comparable with blank video tape. Early reports have suggested that discs can only be re-written up to 1000 times; advances in disc manufacture are likely to improve upon that, though it is unlikely to be an issue for most consumers.



DVD+RW (that's DVD 'plus' RW) is the only format mentioned here that isn't backed by the DVD Forum, however, the system's proponents represent important and highly influential segments of the home entertainment and PC industry.


The group is headed by Philips, which is on course to launch a machine this year, possibly by the summer. Philips is joined by such well-known names as Sony, Hewlett Packard, Mitsubishi, Ricoh and Yamaha. Recent reports have suggested Sony's support for DVD+RW may be waning. It certainly has more experience than most in the outcome of video recording format wars, and appears to be hedging its bets, later this year it plans to introduce what would effectively be a dual standard machine that can play and record both DVD+RW and DVD-RW discs.


DVD+RW is not radically different to DVD-RW with which it shares a number of key features and like DVD-RW discs can hold up to 4.7gigabytes of data. Discs should be fully backwards compatible with existing DVD-Video players and DVD-ROM decks and recent demonstrations appear to confirm that this is the case. The most significant difference is that DVD+RW supports both CAV (constant angular velocity) and CLV (constant linear velocity) recording. This allows for greater flexibility in recording and playback enabling users to choose between the rate at which data can be read onto and off a disc, and access time. Blank and recorded discs are reasonably robust and can be handled – with care – like ordinary DVDs. Initial reports suggest that discs can be re-written up to 100,000 times and have a life expectancy in the order of 50 to 100 years with proper storage.


For the record DVD+RW uses a phase change recording system and 'wobble groove' writing method and like DVD-RW employs similar track layout, data recording and error correction methods as CD-R/RW. Because it is largely based on established and mostly tried and tested technologies players should be affordably priced, assuming the system gains widespread acceptance and the economies of scale are allowed to kick in. Fans of DVD-RW suggest that player prices should swiftly fall to between £600 and £700 soon after an industry-backed launch and for the same reason blank discs should also be inexpensive and although no-one is officially prepared to talk prices, £10 has been widely mentioned as a likely starting point.



DVD-RAM (the RAM bit stands for random access memory) was the first rewritable DVD format to make it into large-scale production back in 1998. So far it has been used for data storage on PCs and the hardware has been confined to 'bare' drive units made by Panasonic and Hitachi, but home video decks are expected in the shops over the next few months. The first machines are likely to come from Panasonic -- the format's principle backer -- and Samsung. Hitachi has just unveiled a DVD-RAM camcorder, using compact 5cm discs.


From a technical standpoint the format differs from DVD-RW and DVD+RW in a number of significant ways. First it uses a specialised phase-change and unique 'wobbled land-and-groove' recording technique. Data can be read and written 'randomly' rather than sequentially (as is the case with DVD-RW and DVD+RW) so access times are significantly lower. Another very unusual feature is that there are three types of disc. The first, Type 1 is double sided and has a capacity of 9.4Gb, however it is very delicate and cannot be handled safely; to keep our grubby, greasy fingers at bay discs are housed in a protective case or 'caddy', which will only fit into PC drives, making it incompatible with existing DVD-Video players. Type II discs have a capacity of 4.7Gb, they are also supplied in caddies but the disc can be removed and, it is claimed, will play on DVD-Video decks. The snag is that apparently once the disc is out of the caddy it cannot be re-used. Recently introduced Type III discs are caddy-less they can also hold 4.7Gb of data and are supposedly compatible with DVD-Video players, though we'll have to wait until hardware is actually available before we know for sure.


Although DVD-RAM discs are not as hardy as their rivals they can withstand more than 100,000 recording cycles but initially blanks are likely to be a little more expensive than either DVD-RW or DVD+RW discs. There's no definite word yet on the cost of home deck recorders. DVD-RAM drives for PCs are between three and four times the price of CD-RW drives but that isn't necessarily a reliable indicator. However, news that Korean-based manufacturer Samsung, which has an impressive track record in bringing down the cost of home entertainment technology, intends marketing a player suggests that they will be competitively priced.





The best possible outcome is that on-going discussions between the interested parties will continue and come to a favourable conclusion, resulting in a hybrid system based on the best bits of DVD-RW and DVD+RW. This must happen quickly though – within the next six months -- before serious quantities of hardware reach the market. If it comes to a showdown the smart money is on DVD-RW, mainly because it has the backing of the DVD Forum, the widest industry support and the best chance of getting the most hardware into the market at the lowest prices. Either way, buying any sort of recordable DVD system at the moment is a big gamble!




For a while, back in the mid 1990s two other disc-based digital recording systems were in contention. The first was ASMO – now that's a name we can live with  -- it stands for Advanced Storage Magneto-Optical, (aka MO7) and it belongs to the same family as MiniDisc. It had wide industry support, discs held up to 6Gb a side and could be re-written millions of times, compatibility with DVD was also touted but it started to look too expensive for consumer use. MMVF (MultiMedia Video Format) also showed a lot of early promise with large capacity and fast access times there were questions over durability.


There are two tape based digital recording systems available right now. DVC first appeared in the mid 1990s and is now doing very well, but as a camcorder format. Full-size DVC cassettes have recording times comparable to VHS but Sony were the only ones to produce a home deck. It lives on, as professional recording format and in video surveillance applications. D-VHS first appeared in 1997, VCRs are backwards compatible with analogue VHS and can, in theory, do amazing things, like record several digital TV channels at once, but the first machines, launched in late 1999 had none of these features and so far have only been of interest to video movie-makers as a high quality archiving medium for digital camcorder recordings


Several video recording systems using PC type hard disc drives have started to appear. PVRs or personal video recorders are geared towards time-shifting TV programmes but they have no permanent archiving facilities and in order to keep a recording they have to be connected to a VCR. One way or another it looks like whiskery old VHS is going to be with us for a while yet, at least until something as convenient and affordable comes along, and with some VCR owners having collections running to hundreds of tapes it's successor has a very tough act to follow!




Ó R. Maybury 2001, 0202





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