PIP bandwidth question

[richteer]

Obviously disc storage will be shared between the main picture and any PIP content, but what a bout bandwidth? Blu-ray has a bandwidth of 48 Mb/s, but is that bandwidth shared between the main feature and the PIP content (when the latter is being displayed), or does each stream have the full 48 Mb/s available to it?

Hopefully the latter...

[dialog_gvf]

Originally Posted by richteer

Obviously disc storage will be shared between the main picture and any PIP content, but what a bout bandwidth? Blu-ray has a bandwidth of 48 Mb/s, but is that bandwidth shared between the main feature and the PIP content (when the latter is being displayed), or does each stream have the full 48 Mb/s available to it?

The bandwidth is shared between all audio and video channels (and subtitles, etc). Think of packets of information continuously laid out on the disc. The player uses the content it wants, and throws away the content it doesn't.

The BDMV transfer spec is 54Mbps from the drive. And the mux bandwidth is 48Mbps.

Gary

[phloyd]

This whole thing about HD PiP is kinda interesting.

The scenarios really are as follows:

480p PiP using not a lot of bandwidth.

720p Secondary using maybe 10 - 15 Mbps, leaving more bandwidth than HD DVD has left over.

1080p using close to half the bandwidth, limiting the peak bandwidth for the main feature unless a stat mux encode is done.

I think that any studio would need to have damn good reason to use 1080p for the secondary. However the 720p option is still HD and leaves a decent amount of bandwidth capacity for the main feature.

[tvted]

Originally Posted by phloyd

I think that any studio would need to have damn good reason to use 1080p for the secondary. However the 720p option is still HD and leaves a decent amount of bandwidth capacity for the main feature.

Agreed completely, and as I suggested in the Insider's Thread I would prefer the primary stream gettting the lion's share.

Its interesting that this might disappoint some, in light of the fact that the vast majority of us in various polls have suggested that extras are not a major consideration. PIP might be useful to film students and some cinephiles but if I'm anything like tha rest I'm not going to spend a lot of time with it. Given my personal time constraints I've still about 20 BD's on the shelf yet to be watched.

ted

[WickyWoo]

No matter what, no one is going to be shooting much 1080p PiP, except for maybe some FX comparisons. If someone thinks they'll do a 1080 stream alongside the movie that's just not going to happen, because there's honestly no reason for it

[Smackos]

Also, might be wrong in my own personal point of view on this but since HD is 4 to 5 times the resolution of Standard Def even at larger screen sizes surely at most 720p is needed for the secondry stream since just like a seperate screen it'd have it's own viewable distances at where HD is visible over SD..being a quarter of your screen is'nt going to make any real difference for all but the ultra high end/largest projector screens etc.. any thoughts?

[The Big Blue]

With certain PIP features you might want to swap images in which case you'd want the best possible vid. for the secondary stream?

[dialog_gvf]

Originally Posted by The Big Blue

With certain PIP features you might want to swap images in which case you'd want the best possible vid. for the secondary stream?

Sure. The thing here is that creative people come up with ways to use features that nobody ever thought of. So, you don't want to limit the possibilities because of current thinking or minor cost reductions.

But, here are some I can think of:

For an animated feature, you could choose to watch the voice actors doing their lines with the feature as PiP. Robin Williams, for example, is known to be physical in his voice acting.

Or how about watching Monster House in the mo-cap form? (The actors wore suits and the computer animated over their physical performances)

Or the 300 and World of Tomorrow blue screen.

Gary

[The Big Blue]

Sky Captain and the World of Tomorrow, Beauty and the Beast final and workprint...

[dialog_gvf]

A Scanner Darkly live action.

[Smackos]

I see what you mean as far as for full content goes but again the smaller picture in the corner would'nt require full HD as people have been showing dissapointment for in the insider thread on the subject. Most of whats been said here only requires SD or 720p maximum in PIP or a 1080p main screen focus, well for me anyway.... fair enough if it means all that much to you guys though.

[dialog_gvf]

Hey, the extra isn't that important to me. I have an alterior motive. I want to insure the hardware is there for a 3D capability in a few years.

Baby step upgrades and backwards compatibility are keys to 3D introduction.

If 3D gets deployed theatrically like they're talking about now, 3D becomes a huge incentive for the mass market to upgrade. And only Blu-ray has the bandwidth and capacity to make it feasible.

Gary

[Smackos]

Originally Posted by dialog_gvf

Hey, the extra isn't that important to me. I have an alterior motive. I want to insure the hardware is there for a 3D capability in a few years.

Baby step upgrades and backwards compatibility are keys to 3D introduction.

If 3D gets deployed theatrically like they're talking about now, 3D becomes a huge incentive for the mass market to upgrade. And only Blu-ray has the bandwidth and capacity to make it feasible.

Gary

Thats fair enough mate, quite like the idea of that but then again surely they can do what they just do now and do it with an interlaced alternate framing sequence, one for each eye.. Although I'll give you that one though, it pretty much makes a 1080i picture out of a 1080p image...

[dialog_gvf]

Originally Posted by Smackos

Thats fair enough mate, quite like the idea of that but then again surely they can do what they just do now and do it with an interlaced alternate framing sequence, one for each eye.. Although I'll give you that one though, it pretty much makes a 1080i picture out of a 1080p image...

But that wouldn't be compatible for people without 3D capability. It would look like a mess.

The dual HD stream method allows fully 2D backward compatible 3D. People without out new 3D capable equipment, or those who simply prefer to watch the movie in 2D, would still be able to watch it that way from the same disc.

Eliminating as many potential roadblocks now is how something becomes possible in the future.

Gary

[WickyWoo]

Sure. The thing here is that creative people come up with ways to use features that nobody ever thought of. So, you don't want to limit the possibilities because of current thinking or minor cost reductions.

The cost difference between a 480p decoder and a 1080p, in either dollars or FLOPS is anything but minor.

For an animated feature, you could choose to watch the voice actors doing their lines with the feature as PiP. Robin Williams, for example, is known to be physical in his voice acting.

Or how about watching Monster House in the mo-cap form? (The actors wore suits and the computer animated over their physical performances)

Or the 300 and World of Tomorrow blue screen.

Neither one needs to be 1080, and as peopel are going to find with 300 next week, the "watch it in greenscreen" thing gets old, fast.

The dual HD stream method allows fully 2D backward compatible 3D. People without out new 3D capable equipment, or those who simply prefer to watch the movie in 2D, would still be able to watch it that way from the same disc.

Eliminating as many potential roadblocks now is how something becomes possible in the future.

The number of people who would spend the money to have the hardware to take advantage of it, is so small that it's not even worth bothering with. You'd sell 10x as many "pure 3-D" copies, and you wouldn't have the bandwidth nightmare to deal with.

It's simply not practical, as Paidgeek has been tryign to explain

[richteer]

Originally Posted by dialog_gvf

The bandwidth is shared between all audio and video channels (and subtitles, etc). Think of packets of information continuously laid out on the disc. The player uses the content it wants, and throws away the content it doesn't.

Thanks for the info. I'd say that shared bandwidth is another reason to eschew PIP. I want all available bandwidth dedicated for the main feature! Even if one isn't watching the PIP, presumably the movie will have to be authored at a sufficiently low bitrate to leave bandwidth for the PIP? In other words, does the availablity of PIP on a given movie restrict that movie's bandwidth, even if the PIP feature isn't being used?

[Anthony P]

Just my .02$

the AV is 48mbps but video is 40mbps, also unlike HD DVD there is no limit on PiP just that the two together must be <=40

why could so much be needed for "PiP" because it is not PiP but a secondary video.

Here are some examples

Imagine the original Star Wars where you can see the original and the changes in the latest DVD? Where you can see either in a PiP and switch back and forth


The second screen could be a full screen PiP, the director walking all over the screen while talking (for example taped in front of a green screen that is superimposed

In an other thread there are a few of us asking for real 3D, the idea is to have both be full screen and then output it two projectors