Ask questions to Sigma Designs insider "kjack"

[patrick99]

What I have read indicates 50 percent more disc space needed for 3D compared to 2D.

[Penton-Man]

Move over HDTV - the campaign begins .............
http://clipta.com/Move_Over_HDTV_--_...ere__nMzAyNjQz

[4K2K]

With the BD 3D spec released today, where online can we read the full details of the spec?

[Jeff Kleist]

I think to do that would require a large upfront cash payment and an NDA There's a consumer document following in the next few buis days I think

[kjack]

True, it's not going to happen unless somebody breaks their NDA...besides there is no separate 3D spec - it's incorporated into the full BD spec.

[4K2K]

Will most or all 3D Blu-ray players include an option to output in anaglyph 3D (with options for red+blue, red+cyan and other colours)?

Does the Blu-ray 3D spec, which uses Multi-view encoding, limit the number of views to 2, and if it does, would it be possible at some future time to increase the number? What's happening with TVs using multiview?

Will the players and TVs allow 3D motion interpolation?

If the players will be outputting at 2x60p, does that mean they will allow motion interpolation in 2D above 60p? Or outputting 2D video at 120hz, so less/no slowdown when switching between 24hz and 60hz content?

Is it possible to make chips that can switch immediately (without glitches or pauses) between different rates, eg. 24hz, 50hz and 60hz?

Why didn't they make 3D Blu-ray discs not compatible with current players, so that it would allow better quality 3D eg. including twice the bitrate and the 2D version for current players wouldn't be lower quality, and make it so that all 3D releases also included a separate disc with a 2D only version?

[Jeff Kleist]

Why didn't they make 3D Blu-ray discs not compatible with current players, so that it would allow better quality 3D eg. including twice the bitrate and the 2D version for current players wouldn't be lower quality, and make it so that all 3D releases also included a separate disc with a 2D only version?

The same reason why Universal is trying flippers right now. There is no way the studios would sign onto something that would require them to ship 2 discs every time they want to do a 3D title.

The methodology they're using is actually pretty sound, since the difference between the left and right frames is pretty slight as far as MPEG compression goes. Remember that MPEG is a very fluid and dynamic medium, and you can do a lot with a little. That's why you get a spike when a shot changes, and then it's way down after that for example

[4K2K]

Originally Posted by Jeff Kleist

The methodology they're using is actually pretty sound, since the difference between the left and right frames is pretty slight as far as MPEG compression goes. Remember that MPEG is a very fluid and dynamic medium, and you can do a lot with a little. That's why you get a spike when a shot changes, and then it's way down after that for example

But I don't think needing an average of 50% more bitrate and space will be a slight increase and I think it could impact the quality, which is why I think they could include a separate 2D-only disc so that quality isn't affected, since they often do for digital copies (that I've never used, and are only a low quality version of the film).

[Jeff Kleist]

But I don't think needing an average of 50% more bitrate and space will be a slight increase and I think it could impact the quality, which is why I think they could include a separate 2D-only disc so that quality isn't affected, since they often do for digital copies (that I've never used, and are only a low quality version of the film).

I didn't say that was a slight increase, I said from a compression standpoint the difference is fairly slight.

[EWL5]

Originally Posted by Jeff Kleist

I didn't say that was a slight increase, I said from a compression standpoint the difference is fairly slight.

The ironic part is since 3D debuts so close to the digital TV transition, most people won't have a good feel for how a pristine 1080p signal can look (ie. Blu-ray). In other words, most people who just upgraded to HD and watching 3D for the first time probably don't have as good a frame a reference as us early adopters and probably won't see the compression difference.

I've owned HD-capable displays since 2002 and probably can't make the same claim.

[Jeff Kleist]

Well, 3D probably isn't going to look pristine no matter how you slice it. By using the extension format, it saves a lot of disc space and bandwidth because most of the alternate eye frame is already there, just slightly different. From a compression standpoint, 3D is somewhat like a constant pan (or that's how it was explained to me)

[Talkstr8t]

Originally Posted by 4K2K

But I don't think needing an average of 50% more bitrate and space will be a slight increase and I think it could impact the quality, which is why I think they could include a separate 2D-only disc so that quality isn't affected

We worked hard to ensure that adding 3D to the spec wouldn't compromise picture quality. In addition to lots of visual tests to ensure that MVC produced acceptable results (meaning video quality wouldn't be compromised in a meaningful way), the maximum bitrate was bumped up to provide more headroom.

- Talk

[4K2K]

Originally Posted by Talkstr8t

We worked hard to ensure that adding 3D to the spec wouldn't compromise picture quality. In addition to lots of visual tests to ensure that MVC produced acceptable results (meaning video quality wouldn't be compromised in a meaningful way), the maximum bitrate was bumped up to provide more headroom.

- Talk

That's good, especially the last part. But how can the maximum bitrate be increased but still maintain compatibility with current Blu-ray players, which will read a max of 40 mbps for the video - aren't current players basically going to be reading the same data but ignoring the second stream?

Can you say how much the maximum bitrate was increased to? Can stream one use the full video max of 40 mbps in a 3D encode and the other stream can use even more?

Also is Blu-ray MVC restricted to 2 views (ie. left & right)?

[jcc]

Question: Does the 3-D Blu-ray spec require HDMI 1.4 or not?

Since it was announced that the PS3 will be supported, and the PS3 has HDMI 1.3, I say not. This has implications on having to upgrade your AVR for HDMI passthru, which would suck. If anything, "HDMI 1.4 cables" may be needed if you have a very long cable run, but not for 1-2 meters. That's my guess, anyway.

Also, as I understand it, the display method could be anything that can display 3-D, including active glasses, "Z screen" and passive glasses, polarizing projector and passive glasses, autostereoscopic display, or even anaglyph.

My ideal would be to have a player that will generate anaglyph on the fly if the display doesn't support 3D (since it will be a few years before I can afford a new 3D HDTV). It might be a tall order for early standalone players to do it, but certainly the PS3 has the processing power to generate anaglyph, if SONY chose to implement it.

[Anthony P]

Originally Posted by 4K2K

That's good, especially the last part. But how can the maximum bitrate be increased but still maintain compatibility with current Blu-ray players, which will read a max of 40 mbps for the video

the 40 is immaterial because it is the video spec (i.e. it means that the player has to be able to process 40mbps mpeg-2/AVC/VC-1 decoding) the issue is the 48mbps A/V and the 54mbps. But then again those are min for players. If every player has >54mbps read then upping it for new specs should not be an issue, but it would be interesting to know the new specs.

[4K2K]

Originally Posted by Anthony P

the 40 is immaterial because it is the video spec (i.e. it means that the player has to be able to process 40mbps mpeg-2/AVC/VC-1 decoding) the issue is the 48mbps A/V and the 54mbps. But then again those are min for players. If every player has >54mbps read then upping it for new specs should not be an issue, but it would be interesting to know the new specs.

It's not immaterial because it is the video portion (not the audio) that needs the average of 50% more bitrate - the BDA talked about needing about 50% more and the only thing that has changed is more view(s) being added (video) - well maybe graphics & subtitles may need more bitrate too now. So if this bitrate has been increased, that's good, but I would like to know how it can be increased but still be compatible with current players - which will surely need to read the same video file as the new 3D players read, but surely only up to their current bitrate specs, and if the 40 mbps video bitrate max has been increased, how much it has been increased to.

[kjack]

Originally Posted by 4K2K

That's good, especially the last part. But how can the maximum bitrate be increased but still maintain compatibility with current Blu-ray players, which will read a max of 40 mbps for the video - aren't current players basically going to be reading the same data but ignoring the second stream?

The decoding chips in the current players can handle far more than 40 mbps.

[4K2K]

Originally Posted by kjack

The decoding chips in the current players can handle far more than 40 mbps.

Thanks. is that for video only (not including audio & subtitles etc.)? Constantly >40 or just for a very short time? How much extra mbps wil the 3D players be able to decode for video only, excluding audio, if any?

[patrick99]

Originally Posted by Talkstr8t

We worked hard to ensure that adding 3D to the spec wouldn't compromise picture quality. In addition to lots of visual tests to ensure that MVC produced acceptable results (meaning video quality wouldn't be compromised in a meaningful way), the maximum bitrate was bumped up to provide more headroom.

- Talk

I'd be interested in hearing more about this. Video quality is compromised, but not in a "meaningful" way?

[Tok]

Originally Posted by patrick99

I'd be interested in hearing more about this. Video quality is compromised, but not in a "meaningful" way?

It's called spin....

I don't understand this obsession with a format that far less than even 0.1% of content is going to use.

Sounds like this 3D thing is more of desperation move to keep selling newer more advanced hardware.

Again if any quality is comprimised on the 2D version to add 3D then they can keep it and give me a separate release optimized for 2D.