BD vs. HD-DVD bit rate questions

akrycek · 09-30-2007, 12:53 AM

I have some questions about the maximum video bit rates of BD and HD-DVD. I know that BD's maximum video bit rate is 40MB/sec and HD-DVD's is 29.4MB/sec. How much has the lower maximum bit rate hurt HD-DVD? Do many BD's take advantage of the higher maximum video bitrate and go above 30MB/sec? I know the higher bitrate one factor that is supposed to equal a better picture, but I just want to sort all of the loose ends out before I buy into either format.

Thanks.

Krycek

Sehnzeleid · 09-30-2007, 01:46 AM

Pretty sure it's 48MBps for Blu-ray and 36MBps for HD DVD.

It hasn't hurt HD DVD at all. Video codecs like VC-1 and MPEG-4 are so efficient amazing video quality can be reached with relatively low bitrates. The VC-1 encoded TMNT often hovers around the low teens and is just about perfect looking. So "higher bitrates = better video" isn't really true. BDs do go above 30 and some kiss 47+ sometimes, though King Kong (along with a bunch of other titles) look awesome on HD DVD. Being neutral, I've been impressed with more HD DVD transfers than Blu-rays so far, though I've seen less BDs than HD DVDs.

Also remember that bitrate is determined by drive speed. So if over time (like DVD players) HD or BD players get faster drives, the current max bitrates will be pushed higher.

Derb · 09-30-2007, 02:45 AM

Pretty much what Sehnzeleid pointed out.

The Ant Bully & other CGI only titles usually hover in the teens. Movies with lots of fast action on screen usually hover around 25-30 no matter the video codec.

Actually The Ant Bully is the only title I've seen with an average bitrate below 10. The highest bitrate title I've seen was the VC-1 encode of Flightplan, hovering around 35-40 throughout & spiking well past 40. Maybe a title like Kingdom of Heaven may require a lesser bitrate if put on a HD-30 disc than again just look at King Kong. The less amount of space the authors have to work with, the better or should say more through o job the encode should be. So far 30GB has been enough & hasn't hurt the video quality. Extra space does help though. I dunno why Paramount used two 25GB discs for Reds & World Trade Center when both could have easily been put on 1 BD-50 disc. I have been reading BD-50 discs are harder to replicate & most end up in the recycle bin. Any case, I foresee both formats only improving in all areas at this point, not the opposite.

Shadowman82 · 10-01-2007, 02:05 AM

It will be interesting to see how really long movies like the LOTR Trilogy Extended Editions will be handled on either format . Remember those versions of the movies were spread over two discs on DVD .

Ruined · 10-01-2007, 02:08 AM

Quote:

Originally Posted by akrycek

I have some questions about the maximum video bit rates of BD and HD-DVD. I know that BD's maximum video bit rate is 40MB/sec and HD-DVD's is 29.4MB/sec. How much has the lower maximum bit rate hurt HD-DVD? Do many BD's take advantage of the higher maximum video bitrate and go above 30MB/sec? I know the higher bitrate one factor that is supposed to equal a better picture, but I just want to sort all of the loose ends out before I buy into either format.

Thanks.

Krycek

With the new VC-1 and MPEG4/AVC codecs, HD DVD has tons of available bandwidth for video and is not affected in the slightest. Several comparisons have been done on titles that have higher bitrate encodes on BD (such as certain Paramount titles) and there is no difference.

The reason Blu-Ray has a higher bitrate is because it was based off a technology that originally used MPEG2 as the primary codec. With MPEG2, there is a difference with the higher bitrate - but since VC-1/MPEG4 encodes dominate HD DVD, it makes no difference.

Shadowman82 · 10-02-2007, 04:41 AM

Again with really really long films there might be a difference . HD-DVD might have to use more discs . Luckily there are not many really long films ( over 3 hours ) .

Ruined · 10-02-2007, 03:58 PM

Quote:

Originally Posted by Shadowman82

Again with really really long films there might be a difference . HD-DVD might have to use more discs . Luckily there are not many really long films ( over 3 hours ) .

Already several movies in the 3+hr range and they look spectacular on HD DVD. See Troy Director's Cut and King Kong for examples.

ganthc · 10-02-2007, 06:26 PM

Quote:

Originally Posted by Derb

I have been reading BD-50 discs are harder to replicate & most end up in the recycle bin.

Hmm...

http://www.blu-ray.com/news/?id=551

Seems that most are ending up on the store shelves to be bought by customers.

Derb · 10-02-2007, 09:35 PM

Quote:

Originally Posted by ganthc

Hmm...

http://www.blu-ray.com/news/?id=551

Seems that most are ending up on the store shelves to be bought by customers.

Well thats good to know. Last I checked yields were below 75% & if BD-50 replication only improves over time, I'm all for that.

Thanks for the link.

Shadowman82 · 10-03-2007, 04:22 AM

Quote:

Originally Posted by Ruined

Already several movies in the 3+hr range and they look spectacular on HD DVD. See Troy Director's Cut and King Kong for examples.

True . Perhaps they'll end up having to put the LOTR Extended Editions on Two discs on HD-DVD . I think those are longer than pretty much any other film released so far . Then again maybe not . No one knows just how much of the HD-DVDs 30GB those long movies like King Kong or Troy Directors Cut actually use .

videoworx · 10-03-2007, 04:45 AM

Quote:

No one knows just how much of the HD-DVDs 30GB those long movies like King Kong or Troy Directors Cut actually use

King Kong takes up 27.4 Gigs (this includes the entire disc, including any menus/extras)...the information is widely spread throughout the interwebtubenets...

Ruined · 10-03-2007, 04:53 AM

Quote:

Originally Posted by videoworx

King Kong takes up 27.4 Gigs (this includes the entire disc, including any menus/extras)...the information is widely spread throughout the interwebtubenets...

Almost every HD DVD maximizes the potential of the HD15 or HD30 it is stored on - most HD30 discs are in the 25-28gb range. For instance, "Nature's Journey" takes up an entire HD15 disc and it is only 45mins. Does that mean that a 1.5-2hr could not fit on an HD15? Of course not. Clearly this is not evidence that a longer movie could not fit, just evidence that the encoders of King Kong used all the available space. Since then the VC-1 codec has been more optimized and obviously the more time you work on tweaking the encode the smaller you can make it with the least quality loss.

09-30-2007, 12:53 AM	#1 (permalink)
akrycek Actor Join Date: Mar 2001 Location: Chester, VA	BD vs. HD-DVD bit rate questions I have some questions about the maximum video bit rates of BD and HD-DVD. I know that BD's maximum video bit rate is 40MB/sec and HD-DVD's is 29.4MB/sec. How much has the lower maximum bit rate hurt HD-DVD? Do many BD's take advantage of the higher maximum video bitrate and go above 30MB/sec? I know the higher bitrate one factor that is supposed to equal a better picture, but I just want to sort all of the loose ends out before I buy into either format. Thanks. Krycek

09-30-2007, 01:46 AM	#2 (permalink)
Sehnzeleid Actor Join Date: Jul 2006	Pretty sure it's 48MBps for Blu-ray and 36MBps for HD DVD. It hasn't hurt HD DVD at all. Video codecs like VC-1 and MPEG-4 are so efficient amazing video quality can be reached with relatively low bitrates. The VC-1 encoded TMNT often hovers around the low teens and is just about perfect looking. So "higher bitrates = better video" isn't really true. BDs do go above 30 and some kiss 47+ sometimes, though King Kong (along with a bunch of other titles) look awesome on HD DVD. Being neutral, I've been impressed with more HD DVD transfers than Blu-rays so far, though I've seen less BDs than HD DVDs. Also remember that bitrate is determined by drive speed. So if over time (like DVD players) HD or BD players get faster drives, the current max bitrates will be pushed higher. Last edited by Sehnzeleid : 09-30-2007 at 01:56 AM.

09-30-2007, 02:45 AM	#3 (permalink)
Derb Actor Join Date: Aug 2003 Location: canada	Pretty much what Sehnzeleid pointed out. The Ant Bully & other CGI only titles usually hover in the teens. Movies with lots of fast action on screen usually hover around 25-30 no matter the video codec. Actually The Ant Bully is the only title I've seen with an average bitrate below 10. The highest bitrate title I've seen was the VC-1 encode of Flightplan, hovering around 35-40 throughout & spiking well past 40. Maybe a title like Kingdom of Heaven may require a lesser bitrate if put on a HD-30 disc than again just look at King Kong. The less amount of space the authors have to work with, the better or should say more through o job the encode should be. So far 30GB has been enough & hasn't hurt the video quality. Extra space does help though. I dunno why Paramount used two 25GB discs for Reds & World Trade Center when both could have easily been put on 1 BD-50 disc. I have been reading BD-50 discs are harder to replicate & most end up in the recycle bin. Any case, I foresee both formats only improving in all areas at this point, not the opposite. __________________ DVD, HD DVD & BD Collection Finished supporting High-Def. Time for Blu to go mainstream.

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10-01-2007, 02:05 AM	#4 (permalink)
Shadowman82 Actor Join Date: Oct 2004 Location: Canada	It will be interesting to see how really long movies like the LOTR Trilogy Extended Editions will be handled on either format . Remember those versions of the movies were spread over two discs on DVD .

10-02-2007, 04:41 AM	#6 (permalink)
Shadowman82 Actor Join Date: Oct 2004 Location: Canada	Again with really really long films there might be a difference . HD-DVD might have to use more discs . Luckily there are not many really long films ( over 3 hours ) .