A small article in this month's Maximum PC compared the two proposed formats for High-def DVD, Blu-Ray versus HD-DVD. It was interesting to note that the maximum data transfer rate for each format was 36 Mbs. I was hoping that the 100 Mbs data stream from the HVX-200 would not need further compression for storage on high def DVDs, but this is clearly not going to happen. I hope that someone (ideally Panasonic) is writing a codec to convert DVCPRO-HD to a signal that will be recordable on the new discs. I also expect that camcorder manufacturers will take advantage of this higher data stream limit and make HD camcorders that will produce perhaps a 33 Mbs data stream, giving a significantly higher quality signal that the current HDV camcorders which record at 19.7 Mbs (although probably inferior to the HVX-200).

If you do the calculations for DV and current DVD, DV is recorded at 25 Mbs, or 1.5 Gb/min, or 90 Gb/hr which is equivalent to 11.2 GB/hr (note closely the difference between b (bits) and B (bytes). The maximum storage on a one-sided DVD is 4.7 GB, and at the highest quality setting (XP), this plays in one hour. Thus DV is undergoing a roughly 3:1 compression when it is converted to MPEG-2 and recorded on a current DVD. This is very obvious if you have ever hooked up both a DVD player and a DV camcorder to a high-quality TV. The DV picture is very visibly superior. At least with the new high-def DVDs we should be able to have nearly lossless conversion of DV to high-def DVD, since the 36 Mbs data rate will easily handle the 25 Mbs DV data.

Sonys new ENG type F series XDCam HD units are using blue ray, with codecs at 35mbps as opposed to HDVs 19-25mbps

I think your confusing something here... video format/codecs for the HD DVD MEDIA are yet to be confirmed. As an archive media HD DVD isnt as robust or as widespread as BlueRay. At the moment Blue Ray (actually XDCam) is already in use throughout many studios.
This is in reference to BOTH media being used for archival purposes, NOT playback media..
playback would require codec standards and compression

At the moment, the only thing which is confirmed is Dolby Digital Mandatory formats for both of these media devices

With Blue Ray, the way Sony is going, i would be leaning towards the H.264 format for HD playback. This is not confirmed, but sony is REALLY leaning towards this format wihtin its own editing system and its new devices.
WIth HD-DVD im yet to see anything confirmed as to which format will be housed on thw disc. Remember, the HD DVD only fits 30gb which is only several minutes of DVCPRoHD100 1080p. So to be sure, irrespective of the larger capacity media optical disc format you choose you WILL need to compress it down to fit onto the media of chocie.

ANother thing, is that there is no reason why we cant author HD H.264 on standard DVD5 optical discs, all we need is a playback device...

I think your confusing something here... video format/codecs for the HD DVD MEDIA are yet to be confirmed.

Everything I've read for some time now indicates that both types of HD players will support three playback formats: M2T (MPEG2), VC1 (Windows Media) and AVC (H.264). Sony indicated several weeks ago that their first batch of HD movies will use M2T, apparently because that's the easiest format for most studios to work with for now.

It's worth noting here that this means HD DVDs will support archiving and playback of HDV content at its native bit rates of 19-25 Mbps, meaning we'll finally have a delivery format capable of offering end viewers the full quality of what's recorded in the camera. In practice some quality will probably be lost during editing and output back to disc, which is why you might want to start with higher-bandwidth source like DVCProHD.

By the way, I'd say there's a good chance that Toshiba's HD DVD format will become a widespread video archiving solution, because it's going to be cheaper than Blu-ray initially and should be more widely available in computers as a result.

Remember, the HD DVD only fits 30gb which is only several minutes of DVCPRoHD100 1080p. So to be sure, irrespective of the larger capacity media optical disc format you choose you WILL need to compress it down to fit onto the media of chocie.

Actually DVCproHD takes approximately 1 GB per minute, so a dual layer HD-DVD will be able to hold 30 minutes which isn't too bad, if the cost is reasonable. It will apparently be cheaper than Blueray anyhow. However this is only practical for archival as the data rate is too slow to read from the disc.

Cheers

as a storage medium, thers no doubt that it will have its uses..

as for a playback medium, im yet to see any real confirmation in technical spec for the delivery format. We know Dolby Digital is a mandatory audio format and there is a Bit by Bit encode available now (ie, if your video pumps at 19mbps, so will your audio) but theres still other audio formats availabel.

If its true that HD DVD and bluray will both support these M2t, H264 and WMV then that a good thing as there are movies already available in WMV9 HD (got terminator2 in hd right here :) ) but again this is only playable on a decent PC

i guess we'll wait and see and whichever format prevails remains to be seen..

Good News, the Sony Blue Ray discs offer a transfer rate of 72 Mbps. Imagine 18 Mbps more and DVCPRO-HD will be shown in its entirely without any downgrading.
http://www.camcorderinfo.com/content/Sony-Releases-Blank-Blu-Rays-in-Europe.htm

when shooting in 720p24N you aren't using all 100mbs. Don't know what it actually is using, but it's be great if that fit in without compression. But it's probably a moot point because to play it it has to be thrown into a full DVCProHD 100mbs stream right?

Paulo - I read the link in your post, but it is at odds with what I have read elsewhere. I'm going to NAB next month and will ask the Sony rep for a clarification. Its interesting that 72 Mbs just happens to be twice the more-often quoted 36 Mbs maximum rate. I wonder if they were refering to reading both sides of a double-sided DVD simultaneously ? Anyway, to get full DVCPRO HD at the highest frame rate, another 28 Mbs would have to be added. It will probably be awhile before that occurs. Although some current computer hard drives can achieve this data transfer rate, most top out at about 80 Mbs in real life.

Don't forget mpeg2 is a lot more efficient compression method than mpeg 1. 34 mb seems more than enough to have good looking delivery picture from the DVCPROHD codec...

as for a playback medium, im yet to see any real confirmation in technical spec for the delivery format.

This has been so widely discussed I won't take time to go find a specific reference, but every indication is that both types of players will support all three codec options I mentioned. I've heard of no plans for them to support DVCProHD, and that's not even a widely supported playback format on computers yet. DVCProHD is strictly an acquisition codec for most purposes, and delivery is likely to move more towards highly compressed solutions than less compressed ones.

Mark Donnell,
Thanks for the clarification of my post, I didn’t realize that I did the math wrong since I wrote that to quick.

That would be completely amazing if Blue Ray players were to stream DVCPPRO-HD to your HD TV.

Sonys new ENG type F series XDCam HD units are using blue ray, with codecs at 35mbps as opposed to HDVs 19-25mbps

I think your confusing something here... video format/codecs for the HD DVD MEDIA are yet to be confirmed. As an archive media HD DVD isnt as robust or as widespread as BlueRay. At the moment Blue Ray (actually XDCam) is already in use throughout many studios.
This is in reference to BOTH media being used for archival purposes, NOT playback media..


We need to keep BR and XDCAM HD in separate camps because while the both use blue laser they are different media.

The PD media used by XDCAM HD has been proposed for use as a DATA storage device. In that role it could be used as an archive media. But, Sony just announced PD was not going to be used for data.

I suspect the reson is that while it was important to Sony to keep XDCAM not compatible with BR -- thereby ensuring folks would have to buy expensive PD media -- not cheap BR media. When it came to data, the reverse was true. Data needs to be able to work with computer BR drives.

The 72Mbps data rate is double-sided media. Two heads are used. But, to keep recording time the same, the disc will hold 2X more. This could be done by double density or dual layer. I assume the later.

24PA is about 40Mbps. So it should be able to be easily played -- as video -- from the 72Mbps drives. Alas, 100Mbps P2 will not

However, for archive use -- the burners will only write at 2X -- so it will take a long while to copy a P2 card to BR! I posted the times awhile back.

So far only hard discs can realtime archive P2. And, if you have only a limited number of P2 cards -- you really need realtime archive.

Sony just announced PD was not going to be used for data. I suspect the reson is that while it was important to Sony to keep XDCAM not compatible with BR -- thereby ensuring folks would have to buy expensive PD media -- not cheap BR media.

While I enjoy a good conspiracy theory, I don't particularly see that at work here. The XDCAM recording discs are currently selling for a modest $30 or so for 23GB of storage, compared to an estimated initial price of at least half that for a blank 25GB Blu-ray disc with no protective cartridge. Compare that to the current price of ~$175 per GB (!) for P2 memory cards which could be replaced by off-the-shelf products costing 1/3 that much, and I'd say we're looking in the wrong place if you want to say there's a conspiracy afoot.

ANother thing, is that there is no reason why we cant author HD H.264 on standard DVD5 optical discs, all we need is a playback device...

How about a HD-DVD Player?

According to the official specifications (http://www.dvdforum.org/images/Forum_HD_DVD_Universal_24.pdf), a HD-DVD can be created using a standard DVD-R, and as all players will be equipped to play back DVD-R discs at 3x speed, it will be capable of sustaining the same high data rates as actual HD-DVD media.

The only limitation is the decreased storage space, but a DVD9 will still be large enough to house 135 minutes of 1080p24 content, using H.264/AVC at an average bitrate of 8Mbps. In fact, this is exactly what Warner Brothers will be doing for their initial HD-DVD releases.

Apple's DVD Studio Pro 4 (http://www.apple.com/finalcutstudio/dvdstudiopro/), part of Final Cut Pro, is already capable of authoring such discs.

I don't know why this feature of HD-DVD isn't discussed more. In my opinion, it is the single greatest difference between the two formats, and a massive "plus" for the HD-DVD camp.

I don't know why this feature of HD-DVD isn't discussed more. In my opinion, it is the single greatest difference between the two formats, and a massive "plus" for the HD-DVD camp.

This is the first I've heard anyone claim for sure that blue-laser players of either type will play HD content placed on red-laser discs. This is something which would be of great usefulness to many of us, as it would negate the need for expensive new burners or discs until customers care enough for that to matter. But I can't think of any reason why the Toshiba players would be able to do this and Sony players not, since both have similar technical hurdles to overcome to do so. Can you provide a published reference addressing this issue?

I'd say we're looking in the wrong place if you want to say there's a conspiracy afoot.

True now. But think 2-3 years out. BR will be much, much cheaper as Chinese plants come on line. Just like MiniDV tapes got much, much cheaper as supplies come on line.

Now Sony would say, and they are likely correct, is the media needs to be extra rugged.

Does anybody care for a mini Blue Ray disc HD camcorder? Now that would be a good idea.

I think Sony should take note.

Now Sony would say, and they are likely correct, is the media needs to be extra rugged.

Works for me: I've never trusted unprotected discs where the active surface can easily be damaged or dirtied during normal use. I was surprised to find out how little XDCAM discs cost today for what they do, and hopefully they'll drop in price even further as blue-laser technology becomes commonplace. Even at current prices XDCAM isn't bad for archiving the master recorded copy, e.g. compared to the cost of putting an hour of DVCProHD footage on an inexpensive hard drive.

Thus DV is undergoing a roughly 3:1 compression when it is converted to MPEG-2 and recorded on a current DVD. This is very obvious if you have ever hooked up both a DVD player and a DV camcorder to a high-quality TV. The DV picture is very visibly superior. At least with the new high-def DVDs we should be able to have nearly lossless conversion of DV to high-def DVD, since the 36 Mbs data rate will easily handle the 25 Mbs DV data.

interesting, i never thought of it quite like that... but there is another alternative.

it's very typical for people on this forum to try and define everything by bitrate, as you've done there... however, the attraction of hd dvd isn't with it's higher bitrate, rather, it's the use of superior codecs that holds the most promise.

for instance, if you encoded that 25 Mbs dv stream into a 25 Mbs vc-1 or h.264 stream, it would be difficult for you to tell the difference between the camera original and one of those copies... either of those codecs is a far superior alternative to using mpeg2 on a dvd.

so when people are putting that hvx footage onto a disk, they won't have to compromise it's picture quality with mpeg2.

This is the first I've heard anyone claim for sure that blue-laser players of either type will play HD content placed on red-laser discs. This is something which would be of great usefulness to many of us, as it would negate the need for expensive new burners or discs until customers care enough for that to matter. But I can't think of any reason why the Toshiba players would be able to do this and Sony players not, since both have similar technical hurdles to overcome to do so. Can you provide a published reference addressing this issue?

AFAIK, the HD-DVD video standard has provisions to allow any of its supported video formats to be played from any compatible media type. However, it is up to manufacturers to produce players that can do this as this is not a requirement. I would count this functionality right along with DVD players that offer MP3 and WMV playback from CD-R and/or DVD-R or players that can play MPEG1/2 VCD and SVCD video formats from either type of disc.

I recieved this information from a document on the offical website of the DVD Forum, as linked to in my original post. It is a full part of the specs, not an optional extra like MP3 or JPEG support available on some DVD players on the market now.

Here it is again:
HD DVD - A Technical Introduction (http://www.dvdforum.org/images/Forum_HD_DVD_Universal_24.pdf)

Another document is available which also references this part of the HD-DVD specification:
HD DVD White Paper 1.0 (http://www.dvdforum.org/images/HDDVD_White_Paper_1-0.pdf)

The first paper is available in other languages on the official DVD Forum website (http://www.dvdforum.org/hddvd-whatis.htm), for those that prefer to read in their native tongue.