H.264 details for BluRay/HD-DVD?

john-beale wrote on 5/11/2006, 10:17 PM
As we all know there are many kinds of MPEG2 streams (bitrate, resolution, color sampling, etc.) Some are valid for (standard-def) DVD authoring, some are not.

I don't have any BluRay or HD-DVD gear yet, but I'm shooting and editing in 1080i now and downconverting to 720x480 for DVD output.

I have tested H.264 encodes at 720p (using the x264 codec) and it looks quite good in playback on my PC at a modest bitrate of 5000 kbps. At that rate I could put almost 2 hours on a normal DVD-R, against the day when set-top HD players are consumer items. Is there any guide for what specific H.264 encode parameters would most likely be compatible with future HD players?

Comments

jwcarney wrote on 5/12/2006, 8:21 AM
I don't think commercial Blue-Ray supports h.264, mpeg2 only as far as I know.
DJPadre wrote on 5/12/2006, 8:42 AM
thing is the discs themselves will supprt anything really.. however its the players/decoders which may be an issue.. as for h.264, i wish i knew.. coz id already be encoding and archiving my existing jobs to that, and hanging on until the format is open for disc distribution and authoring... as oposed to having to render and transcode then transfer to tape...then restransfer back to HDD to convert to h.264 for authorng.... its just a waste of tme, where as if i could archive these files NOW, id be saving myself countless hours of sittin on this material waiting..
fldave wrote on 5/12/2006, 9:07 AM
From Wikipedia:

Blue-Ray:
The BD-ROM format specifies at least three video codecs: MPEG-2, the standard used for DVDs; MPEG-4's H.264/AVC codec; and VC-1, a codec based on Microsoft's Windows Media 9. The first of these only allows for about two hours of high-definition content on a single-layer BD-ROM, but the addition of the two more advanced codecs allows up to four hours per layer.

For audio, BD-ROM supports linear (uncompressed) PCM, Dolby Digital, Dolby Digital Plus, DTS, DTS-HD, and Dolby TrueHD.

HD-DVD:
Both formats (Blue-Ray & HD-DVD) will be backwards compatible with DVDs and both employ the same video compression techniques: MPEG-2, Video Codec 1 (VC1, based on the Windows Media 9 format) and H.264/MPEG-4 AVC.

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More details, with links to standards in wiki:
http://en.wikipedia.org/wiki/Blue_ray
john-beale wrote on 5/12/2006, 9:57 AM
A bit more research follows:

From http://en.wikipedia.org/wiki/H.264
H.264 High Profile (HiP): The primary profile for broadcast and disc storage applications, particularly for high-definition television applications
(this is the profile adopted into HD DVD and Blu-ray Disc, for example).

H.264 HiP includes 4:2:0 color sampling and 8 bit sample depth.

H.264 HiP also has many "Levels" defined, from Level 1 at 80 kbit/sec through
Level 5.1 at 300 Mbit/sec. I suspect that HD-DVD/BD is targeted at Level 4
with max video bitrate of 25 Mbit/sec, but I haven't seen this confirmed.
According to http://en.wikipedia.org/wiki/Blu-ray_Disc the BD disk is
supposed to play back data at 36 Mbit/s. Even with uncompressed PCM for
audio (1.5 Mbit/s) and formatting overhead, that should be enough for
25 Mb/s video. According to the BD article, audio in Dolby Digital
= AC3 = A/52 (different names, same format) is also allowed.
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Of course it's anyone's guess what will actually work with as-yet-unreleased hardware, but that's the best I could do for now.
DJPadre wrote on 5/12/2006, 10:21 AM
ive been going over info like that now for abotu a month...
its like a chef goes over his recipe bok, however, with all this, these are heresay and speculation until the authoring tools are released and the delivery options are made available to us through the playback devices...
until they can confirm all this, as in, until they can VERIFY that these are in fact the ACTIVE formats available to us , and these formats are proven to be available and efficient (as oppsoed to tech spec and "this is what it SHOULD be able to do.." theres no point..
Until an authoring app is made available, which proves "this is what id CAN do", then theres no point in moving forward...

My point was to encode media to a HD DVD or BD delivery standard BEFORE authoring apps are made available, to save time in to not have to archive a zillion jobs and double handle everything later..

At this time, i cant do that.. If i encode to h.264, how do i know that im using the right spec or bitrate when i dont even know what the ACTUAL standard is..?? How do we know they wont bring out another profile at teh time of launch?? We dont, and thats whats annoying...

Its like VCD, SVCD and DVD... lets say i encoded somethign using the SVCD standard, believing that at teh time, DVD was tainted as SVD but with larger capacity... so i inadvertantly think ahead and encode my material at SVCD standard... THEN to have the launch of the actual meda and be TOTALLY different in spec...
This is my point..

Hell even with BD and HD DVD, we SHOULD also theoretically have the ability to encode Standard Def material using these higher bitrates... NOT HD @ 25mbps, but SD DV encoded to MPG2@whatever SD resolution running at 25mbps...
Theoretically this SHOULD be possible.. and i dont see why it cant do this... and it would make SD DVDs look rather incredible... whether or not this would be possible however, who knows..

i KNOW i can encode an SD 720x576 DV file to M2t,/MPG2 @25mbps.. but whether or not i can author a HD DVD/BD at that bitrate WITH THOSE RESOLUTIONS is another question...

so there are many things left floating in the air at this time, and speculating on spec really doesnt do any good when there is work waiting to be edited and delivered...