Chroma Subsampling of Blu-ray

[gbalaji]

What is the chroma subsampling of Blu-ray.

Will it allow 4:4:4 or 4:2:2 or 4:2:0.

If the above 3 are allowed what will my blu-ray player supports and my hdtv supports?

what blu-ray profile i needs to use for encoding blu-ray movies.

[4K2K]

I think this article says it's always 4:2:0 for Blu-ray (and I don't think the specs allow 4:2:2 or 4:4:4 )

http://www.emedialive.com/articles/r...leid=11397#iif

[welwynnick]

Blu-ray is the same as every other digital video distribution standard in this respect. DTV, HDTV, DVD and HD DVD are all YCbCr 4:2:0, and Blu-ray is the same.

Some versions of some of the codecs may be able to support 4:2:2 or 4:4:4, but the media standards don't. IMHO I don't think this would be a good way forwards for improving quality anyway - increasing the bit depth from 8 to 10 bits per colour would probably be a better way of spending a bigger bit budget, but that's probably a dead duck as well.

BR, Nick

[JadedRaverLA]

Originally Posted by gbalaji

What is the chroma subsampling of Blu-ray.

Will it allow 4:4:4 or 4:2:2 or 4:2:0.

As the others said, Blu-ray Disc video spec calls for sampling at 4:2:0.

Originally Posted by gbalaji

If the above 3 are allowed what will my blu-ray player supports and my hdtv supports?

Here's where it gets a little trickier. Though the video is encoded and stored as 4:2:0, players can be configured to send out 4:2:2 or 4:4:4 component video or convert to RGB, depending on the player's capabilities (and, of course, what your display can accept). If you have a player like the Denon 3800 which has excellent video decoding capabilities and conversion, having it "upsample" to 4:4:4 may produce a slightly improved picture... but for most players and setups you likely won't be able to tell the difference between having the player convert or having it done within your display.

Originally Posted by gbalaji

what blu-ray profile i needs to use for encoding blu-ray movies.

Not quite sure I understand the question. Do you mean "profile" as in Player Profile 1.0, 1.1, and 2.0, or do you mean "profile" settings within your mastering program?

If the first, 1.1 is BonusView Profile and 2.0 is BD-Live Profile... unless you want to use one or the other feature, you don't need to worry about those. Discs technically don't have a "profile," players do. Those two features require a player that meets the necessary profile in order to playback the specific feature... that's all.

You essentially have 3 choices for the actual disc formatting:

• BDAV -- most basic format, simple menus and disc creation
• BDMV -- standard format for pressed discs -- requires an AACS license and key if you actually have the discs pressed, but most players can playback BD-R/RE discs formatted as BDMV without issues -- allows for more complex menu systems than BDAV
• BDMV + BD-J -- Essentially the same as just BDMV in terms of disc format, but can load a BD-J (Java) VM when necessary for advanced special features. Most BD-J features work in all players, with the two exceptions above (BonusView and BD-Live) -- you would only really choose this if you were encoding a major release title or are just way too excited about coding Java -- also, only pro tools (Scenarist, Blu-Print, etc) really allow for full access to prgram in BD-J and you definitely don't want to see what those cost.

If you were asking about the profile within your authoring program, post what program you're using and someone can likely give you the exact profile and settings you want to use.

In general, though:

• For video-based sources at 30p/60i, you'll setup your program for 1080i60 -- if your source is film or video at 24p, setup your program using a 1080p24 profile
• I usually recommend selecting the video codec based on the source for video. If you are bringing in AVC HD files, then use AVC as the video codec and you can generally avoid re-encoding all the video prior to mastering. If your source is video from an HDV camera, its a bit more complicated. You can keep the video in MPEG-2 at the 1440x1080i resolution and not have to reencode if you want, though a lot of people prefer reencoding to AVC at 1920x1080 to lower the bitrate and because its nice for effects and transitions to convert to square pixel format.
• If you're doing a "home" project, you'll generally use Dolby Digtal or 2-channel PCM for audio. The 2-channel PCM takes up far more space, but it will probide the best possible sound and doesn't require compressing the audio, making for a faster mastering process. DTS's and Dolby's lossless formats aren't available in consumer-oriented programs, so you likely won't be dealing with them. Standard DTS is an extra-cost option in some "prosumer" level programs, so, if you prefer that there are a few options out there.

Anyway, if you need more specific help, post back with your mastering program, video source (brand and model of video camera), etc.

Hope that helps.