And every single blu-ray player on the market today will only output 1080p30 as 1080i. They have no 1080p30 output mode, nor will they convert it to 1080p60.
Are you sure? The Samsung BD-P1400 can output at 1080p60 (though I don't have a Nine inch nails disc to try it with).

And every single blu-ray player on the market today will only output 1080p30 as 1080i. They have no 1080p30 output mode, nor will they convert it to 1080p60. It was the same for HDDVD players. And I highly doubt that will change in the future either. So even if you can encode true 1080p30 video on a blu-ray disc you will still be getting 1080i output no matter what. So this whole argument is academic.
Who says if the disc is 30p, the output has to be 60i? BD spec mandates what the disc is, not what the player would do with it. A player could take 24p and output 120p and BDA would have nothing to do with it. A disc gets created once, players come and go.

There really is no defence for lack of 30p in BD spec. The silicon supports it as evidenced by HD DVD. And if you are not careful, when you convert to 60i, you may wind up with an encoder throwing its interlace tools at it, rather than progressive. In which case, the results may not be identical to 30p native encoding.

Someone goofed here. Not a big deal since this is an odd frequency but goof it is...

Sometimes I lock my car. Or my shed. I use locks on many things. My locker at work, my safe in the bedroom.

Locks are very useful. I once saw a lock shot in 1080/60i. I wonder if it would have looked better in 1080/30p.

*sigh* If only HD DVD was still around so I could tell for sure.

BTW

I did once have to lock the hallway linen closet because my toddler would pull all the towels out.

I never said it HAS to be 60i. I said no CURRENT player does anything other than 60i output. When and if that ever changes then maybe this argument will have some relevancy. But as of right now it has none.
The argument is just as valid today because the day that player comes out, the disc you bought in 60i doesn't all of a sudden become a 30p disc :).

You want the disc to be ready for your new player not the other way around. Besides, the assumption about current players is incorrect to some extent anyway. See below.

Really? When HDDVD players encountered 1080p30 video how did they output it?
Using that famous phrase, "However it wanted to?" :D

As I mentioned, the player is free to output what it wants, regardless of whether it is BD or HD DVD. PC players for example, are able to decode and output native frame rate of the disc (or multiples of it). I have not kept track of what they did with 30p in stand-alone players. But even if support was not there in the box, firmware changes could have enabled them to do what PC players are doing.

And if I were writing PS3 firmware, I could easily have it output 60p if 30p was in the spec and the disc used it. But since it isn't....

Allow me to answer my own question. The answer is 1080i which obviously you don't want to admit.

Where then is the "evidence" that the silicon supports 1080p30?
Aren't we arguing over minutiae at this point? If the hardware that exists for HD DVD outputs 1080p30 source as 1080i60 (I'm not aware of any normal displays that will take a 1080p30 signal?), then we're back to square one where encoding 1080p30 source on the disc as flagged 1080i60 is identical to having the player decode 1080p30 and render it as 1080i60 output; what matters is what the display device sees. The reality is that there isn't any new firmware that will be released for the aforementioned hardware, so commentating that it "could" be firmware updated to output 1080p30 properly is a red herring.

Granted, an HTPC could do a proper 1080p30 output to a display... but in that case, any PC that can handle that sort of computational load is more likely than not capable of deinterlacing flagged 1080i60 back into 1080p30, so again... what's the point?

Allow me to answer my own question. The answer is 1080i which obviously you don't want to admit.
What do you think the answer is in this scenario: Xbox 360 set to 1080p/60 output and 30p disc being played. You think it auto-switches to 1080i on its output to play such disc?

Second and more important question for you. If 24p were not part of the BD disc and all current BD players put out 1080i60 and 1080p60, would it be your position that there would have been no reason to have 24p native encoding mode since no player can output it today?

You see the fallacy in the logic? No amount of tap dancing around this does anything but leave one’s shoes worn out :). Really, it cost nothing to have 30p native support. You as a consumer should have zero reason to defend a hole in the spec. If you could have gotten something for nothing, you should be demanding that the spec be retrofitted to add it in.

Where then is the "evidence" that the silicon supports 1080p30?
30p is a required frame rate specification for HD DVD. As such, any decode silicon in an HD DVD player must support 30p. 30p requires the same decode horsepower as 60i. So from silicon provider point of view it is no more work. Mind you, if you wanted to upsample it to 60p, you may have to use an external processor like the high-end players did. But the core decoder must play 30p. But the decoder silicon must be capable of it.

Aren't we arguing over minutiae at this point? If the hardware that exists for HD DVD outputs 1080p30 source as 1080i60 (I'm not aware of any normal displays that will take a 1080p30 signal?), then we're back to square one where encoding 1080p30 source on the disc as flagged 1080i60 is identical to having the player decode 1080p30 and render it as 1080i60 output; what matters is what the display device sees.
That is making an incorrect assumption :). Once more, if you have to convert the *source* to interlace before encoding, then the codec may assume it is interlace and do different things to do it than progressive. You really don't know the outcome of that conversion.


The reality is that there isn't any new firmware that will be released for the aforementioned hardware, so commentating that it "could" be firmware updated to output 1080p30 properly is a red herring.
What if there were for PS3?

Granted, an HTPC could do a proper 1080p30 output to a display... but in that case, any PC that can handle that sort of computational load is more likely than not capable of deinterlacing flagged 1080i60 back into 1080p30, so again... what's the point?
Sorry, I don't follow what 1080i60 to 1080p have to do with this topic. We know that it is trivial to play 30p as 60p if the display doesn't support it. So why do we have to convert it to interlace and encode it that way? What possible good is there to not have the native mode of these camcorders supported in the format?

And I wonder if they were even outputting direct 24p or if they simply took the 60i output like all other players and converted it back to 24p. This also causes visual anomalies for some material.
Better not "wonder" when making accusations like this. You either know such things or don't.

Really, this discussion is tiring. You keep wanting to have a format war argument. Who cares? Forget HD DVD. Did you accept finally that BD doesn't support 30p and it should? You seem to think flagged 24p is bad. So how come it is just dandy that BD does the same with 30p (and worse, in requiring encoding to happen in interlace domain)?

30p gives you 20% better temporal resolution with no cost in the hardware. Which starving children were saved due to this omission?

So as a consumer, I'm actually glad blu-ray didn't concentrate on supporting this obscure format,
"Concentrate?" How much concentration does it take to support frame rates in camcorders they produce themselves?

Here is a $48,000 Camera from BDA founder, Panasonic: http://catalog2.panasonic.com/webapp/wcs/stores/servlet/ModelDetail?displayTab=O&storeId=11201&catalogId=13051&itemId=116556&catGroupId=34401&surfModel=AJ-HPX3000
“The HPX3000 also records in industry-standard DVCPRO HD at 1080 in 24p, 25p, 30p, 50i and 60i and can produce standard definition recordings in 50Mbps DVCPRO50.”

And Sony $30,000 camcorder: http://pro.sony.com/bbsc/ssr/product-PDW700/

“HD422: 1080: 29.97p, 25p, and 720: 59.94p, 50p”

And there are more of where these came from in both professional and consumer lines.

And in all honesty I would have much rather seen 1080p60 support. Which unfortunately neither format decided to support. And that would have taken care of 1080p30 as a by product too.
Again, 60p costs money in higher power silicon (it would have to run twice as fast). So it lives in a different domain than 30p discussion. And I can just imagine the amount of "concentration" it would have required to support that! :D

What I don't understand is, why the players can only support specific frame rates, instead of just reading whatever rate is specified in the file on the disc itself then outputting at that rate (assuming it has the processing power). I mean - why hard code the frame rates you are going to support?

It's a similar thing with HDTVs only supporting certain rates (I read somewhere on the forum that some can support 1080p30), and some can support 1080p24. I don't know why they can't support every rate <= to their maximum rate.

Perhaps this will change soon since it was said that Sony "showed 1080p60 Blu-ray at NAB"? (and there have been chips supporting this rate for a while too) - yet I didn't know it had been added to the Blu-ray spec yet (I wonder if they'll support 1080p50 too, as well as others).

That is making an incorrect assumption :). Once more, if you have to convert the *source* to interlace before encoding, then the codec may assume it is interlace and do different things to do it than progressive. You really don't know the outcome of that conversion.

If push came to shove wouldn't the answer be to fix the encoding solution, rather than muck about with hardware or firmware in that instance? Sounds to me like such a change should be (relatively) trivial for any encoding package that's actively supported, if such occurrences are troublesome.

What if there were for PS3?
The PS3's not the only Blu-ray hardware out there. Firmware updating it to handle a theoretical change in the Blu-ray spec to support 1080p30 probably wouldn't be terribly difficult (though I'll defer to your experience on the Xbox 360, as they're similar-though-not-the-same environments).

Even so, such a change would have to be propagated across all - or at least most - existing Blu-ray hardware, which would take a lot more effort than just making sure the encoding process doesn't screw things up.

Sorry, I don't follow what 1080i60 to 1080p have to do with this topic. We know that it is trivial to play 30p as 60p if the display doesn't support it. So why do we have to convert it to interlace and encode it that way? What possible good is there to not have the native mode of these camcorders supported in the format?
Again, we're talking about using a workaround to get around a limitation of the specification. I think really the main point under discussion is how good or bad the workaround is, and that workaround involves encoding to interlaced and then using IVTC to recover the image data at the proper framerate.

Also, according to the Blu-ray spec screenshot on page 1 of this thread, Blu-ray can't support 1080p25. Is this correct or is the spec sheet out of date, as according to wikipedia it can support 1080p25 (or does it have to do a similar thing and store it as 1080i50?)

OK. Tell me the answer straight up then so I don't have to wonder. Did 24p output on HDDVD come directly off the disc or did it come from 60i first?
Both were done in different models of stand-alone players from what I recall. Xbox 360 of course, always output it progressive. Reason for some converting the 60i was as to not have to figure out what to do if the source were 60i (or PiP).

And as a follow up to whatever the answer is, can you explain why it caused audio sync issues?
The one I recall was due to programming the output bus to run at 24p, rather than 23.976. Needless to say, that quickly led to audio to be out of sync. Yes, inexcusable. This was fixed in another firmware revision from what I remember but should have never happened.

And why blu-ray players with 24p output don't have these issues?
My BD-10 Panasonic has dynamic sync issues and did so from day one. It would get out of sync but if backed off and played again, half the time it would be good.

In general, audio video sync in consumer devices is a house of cards. First, the mux has to stuff two separately generated streams together even though they were authored separately and don't have frames that represent the same amount of time. Then the player has to keep this relationship the same, even though its audio and video ports may drift with no sync to the original master which created them.

Of course, in theater you have sync issues. If you sit way back or in front, you are not hearing the proper sync as the sound travels too slowly to have sync work for everyone. I forget which row they are timed for but it is somewhere close to middle of the theater.

Having said all of this, I was always unhappy that HD DVD didn’t come out of box with 1080p support from day one. I pushed for this 3 years before the format came out. But was told to pound sand because the TVs didn’t support it and no one wanted a brand X player to put out no picture on the same brand TV. I don’t like how BDA went about it either. They made it a marketing thing to have 1080p60 which was just as bad with locking in judder.

None of us were around when the system syntax for HD DVD was created either or we would have made sure it was true 24p without the useless flags which could have just as easily be generated in the player given the fixed 24p nature of the encodes. Most people forget this but Microsoft got involved in HD DVD when it was at 0.9 revision of the spec. The only thing left to standardize post that period was interactivity, selection of codecs, and a few other tidbits. Fortunately, this didn’t have any adverse effect on the picture quality but still, why have legacy stuff that is not needed.
I'll tell you exactly why. Because I have over 300 blu-ray discs encoded as 24p and only ONE as 30p. As a consumer I know which one is more important to me.
No one said 30p was important. I repeatedly said it was a minor thing. I don’t think anyone should lose a moment of sleep over it. At the same time, I think it is important that we don’t paper over something that was easy and simple to put in but wasn’t.
When do you see foresee 30p being used in any significant amount? Lets define significant as just being 3% of all titles. Will this happen before blu-ray is eventually replaced by downloads? If not it seems unimportant.
At the current rate, there will be the odd title out of 1000 that will use it (mostly direct to video material). Beyond that, there are people like James Cameron who want higher frame rate movie. Maybe if millions BD players already supported 30p, that could have become the next standard although even with that, this is one huge uphill battle.

If push came to shove wouldn't the answer be to fix the encoding solution, rather than muck about with hardware or firmware in that instance?
How do you control every AVC encoder to do the right thing here?

Again, we're talking about using a workaround to get around a limitation of the specification. I think really the main point under discussion is how good or bad the workaround is, and that workaround involves encoding to interlaced and then using IVTC to recover the image data at the proper framerate.
Let me explain what is going here because it is more complicated than this.

Video codecs have two different encoding modes: progressive and interlace. You can encode an interlace movie using progressive but it won't be as efficient. Interlace version of the codec understands that the fields are different in time and using that information, is able to make smarter decisions on how to encode that material.

The interlace logic is not designed to be used for progressive content. The encoder may produce the same stream, or be less efficient if told to do that. The kludge required is to instruct the encoder to generate an interlace stream on its output, but treat the source as progressive. How many people understand this situation and put in the right flag and explain to all the people who use the tool is at issue here.

Thanks amir for the explanations.

Of course no one can argue that you *shouldn't* have 30p. But if it isn't supported though then personally I am not loosing any sleep over it. Every format has compromises (yes even blu-ray :D) and frankly if this is the biggest one, and it only affects a fraction of the content out there, then I'd say thats not bad. I'm pleased though with all the other areas where they got things right.

Then we walk away in peace :).

1. What about the fact that PiP in Blu-ray has to match the frame rate of the video it plays next to (like 24p)? Isn't that a limitation that will affect every title that uses PiP (when the PiP commentaries might look more natural at a higher rate like 30p or 48p/50/60i/p?

2. Why can't players & TVs support all rates <= their max rate?

3. Were 1080p60 players really demonstrated at NAB 2008 - is there any more details on them?

1. What about the fact that PiP in Blu-ray has to match the frame rate of the video it plays next to (like 24p)? Isn't that a limitation that will affect every title that uses PiP (when the PiP commentaries might look more natural at a higher rate like 30p or 48p/50/60i/p?
Yeah, it is an ugly problem. My opinion is that TVs and players have to support 120Hz interconnect/display. Then the player can output both 24p and 60i at 120Hz (5*24 and 2*60) and be done with it. As it is, they the 60i PiP will have to be butchered to 24p and encoded with no chance of ever getting the lost frames.

2. Why can't players & TVs support all rates <= their max rate?
It increases test time for TV but otherwise, I don’t see a reason why they don’t support it for progressive content. Player though, is much more complicated as converting from for example, 24p to 30p is hard. Best to have the TV be flexible and run both at 120 Hz per above.
3. Were 1080p60 players really demonstrated at NAB 2008 - is there any more details on them?
I heard that there was buzz around creating content at 1080p60 by some broadcasters. This has gotten a few people to start thinking about 60p playback in BD players. Hopefully a few years from now, there will be a profile to support 60p.

Yeah, it is an ugly problem. My opinion is that TVs and players have to support 120Hz interconnect/display. Then the player can output both 24p and 60i at 120Hz (5*24 and 2*60) and be done with it. As it is, they the 60i PiP will have to be butchered to 24p and encoded with no chance of ever getting the lost frames.

Wouldnt an alternative be that the player converts the 60i stream to 24P and output both as 24P if the viewer wishes. No need to encode the stream to 24P if they player can do it during playback?

Other then that 120hz display seems like a good standard. (not counting PAL PiPs...)

Wouldnt an alternative be that the player converts the 60i stream to 24P and output both as 24P if the viewer wishes. No need to encode the stream to 24P if they player can do it during playback?
But it would be lower quality than the original 60i (or 60p) recording. It would be missing out frames - or at least merging them into 24 together with artifacts that may create.

Maybe a 48p PiP could be easier to do (though still not compatible with the current specs).
Other then that 120hz display seems like a good standard. (not counting PAL PiPs...)

One problem with outputting from the player at 100hz or 120hz is that I think they'd need to use Dual DVI or some new type of HDMI as I think the current HDMI spec doesn't allow such high frame rates. But I don't see why they can't start adding the required connections to players and HDTVs etc. so that they will be ready to be compatible with these rates.

Sure, the frames are progressive in both cases so we don't have the typical interlace issues to deal with.For anyone curious this is the issue that would matter in terms of encoding efficiency and which several insiders, including sspears (http://www.avsforum.com/avs-vb/showpost.php?p=13998888&postcount=235), have mentioned. As such there is no efficiency difference for anyone that wants to encode 1080p30 video on Blu-ray since it can be encoded using progressive frames.


My opinion is that TVs and players have to support 120Hz interconnect/display. Then the player can output both 24p and 60i at 120Hz (5*24 and 2*60) and be done with it.None of the current HDMI 1.3 chips support a 1080p120 video signal which means that none of the HDMI based displays, AV receivers, or active switchers being released today are capable of 1080p120. Even if there were HDMI 1.3 chips that could support 1080p120 I think it unlikely that most people would pay more (for the display, HD DVD player, and AV receiver) just to get smoother motion with PiP video. Of course with HD DVD dead it is now a moot point.

But it would be lower quality than the original 60i (or 60p) recording. It would be missing out frames - or at least merging them into 24 together with artifacts that may create.

Yes, but I wouldnt get many sleepless nights because of the PiP isnt true to the master.

Its the main picture that should be the priority in terms of PQ.

Yes, but I wouldnt get many sleepless nights because of the PiP isnt true to the master.

Its the main picture that should be the priority in terms of PQ.

+1,000,000,000,000,000!!:D

I can't believe you guys are getting worked up about the frame rate of the picture in Picture video!:confused:

What I want to know is, do Blu-ray players output the 1080p/24 directly off the disc, or does it go through some 24p>60P>24P or 24p>60i>24p process, due to limitations of the hardware? And, when the player is outputting 1080p/60, does it do 24p>60p, or is it 24p>60i>60p, the way HD-DVD did?

+1,000,000,000,000,000!!:D

I can't believe you guys are getting worked up about the frame rate of the picture in Picture video!:confused:

What I want to know is, do Blu-ray players output the 1080p/24 directly off the disc, or does it go through some 24p>60P>24P or 24p>60i>24p process, due to limitations of the hardware? And, when the player is outputting 1080p/60, does it do 24p>60p, or is it 24p>60i>60p, the way HD-DVD did?

All of the 1080p Toshiba, Onkyo and Integra HD DVD players (at least before that last weird AVC rendering mess) do 24p->24p. It was the 24p->60i->60p that caused problems for the 3 Anchor Bay models.

I want the PiP video to appear exactly as the creative artists intended (hopefully 60p, but I'd settle for 48p). If the creative artists decide it will look better or more natural/real at 60p I don't see why we have to totally alter their creative vision by dropping frames or introducing judder or other artefacts or forcing them to record PiP at a rate that they did not intend nor want, nor which gives them the look they envision for their work :)

Yeah, it is an ugly problem. My opinion is that TVs and players have to support 120Hz interconnect/display. Then the player can output both 24p and 60i at 120Hz (5*24 and 2*60) and be done with it. As it is, they the 60i PiP will have to be butchered to 24p and encoded with no chance of ever getting the lost frames.


It increases test time for TV but otherwise, I don’t see a reason why they don’t support it for progressive content. Player though, is much more complicated as converting from for example, 24p to 30p is hard. Best to have the TV be flexible and run both at 120 Hz per above.

I heard that there was buzz around creating content at 1080p60 by some broadcasters. This has gotten a few people to start thinking about 60p playback in BD players. Hopefully a few years from now, there will be a profile to support 60p.

I agree that's the most elegant way to handle it.

Hmm... what's the bandwidth requirement for 1080p120?

HDMI 2.0 anybody? ;)

I want the PiP video to appear exactly as the creative artists intended (hopefully 60p, but I'd settle for 48p).

Its more like it was shoot 60i.

Its more like it was shoot 60i.
Maybe for existing stuff, but for new PiP commentaries, behind the scenes/making of stuff, they may want to shoot with some of the new 60p cameras (there's already 1080p60 cameras, as demonstrated at NAB that they may wish to use).

For PiP stuff, they probably don't even need to shoot at full 1080p res - if the PiP window only appears in around a quarter of the window or less - though if there's an option to make the PiP bit fill the whole screen maybe they could do with recording it at full 1080 lines at 60i (or hopefully 60p).

Though for high quality behind the scenes documentaries, they're probably better off being shown under a different option on the menu instead of being shown as PiP so it can be shown at higher quality and won't affect the bitrate/picture quality of the main feature.

For anyone curious this is the issue that would matter in terms of encoding efficiency and which several insiders, including sspears (http://www.avsforum.com/avs-vb/showpost.php?p=13998888&postcount=235), have mentioned. As such there is no efficiency difference for anyone that wants to encode 1080p30 video on Blu-ray since it can be encoded using progressive frames.
Only if VC-1 encoder is used ;). Don't count on everyone understanding how we did this and not just use interlace mode of the codec and face the issues I mentioned.


None of the current HDMI 1.3 chips support more than a 225 MHz video signal which means that none of the HDMI based displays, AV receivers, or active switchers being released today are capable of 1080p120. Even if there were HDMI 1.3 chips that could support 1080p120 I think it unlikely that most people would pay more (for the display, HD DVD player, and AV receiver) just to get smoother motion with PiP video. Of course with HD DVD dead it is now a moot point.
So what else is new. Another thing HDMI is not so good at. If HDMI doesn't support this, then DisplayPort is standing by: http://www.displayport.org/white-papers/whitepapers/DP_Tech_Overview_English.pdf

Its spec already allows 120Hz, 1080p (at 12-bits per component no less).

We are easily going to have 4K displays in our future so if it is not refresh rate, it will be the display resolution which needs something better.

Also, though I agree we need better connections (better than current HDMI etc.) for sending 120hz video as well as higher res (like 4k), couldn't another alternative be sending dual streams to the TV via the HDMI (or better) connector).

If the player did the PiP and had the 24p video (as 5:5) and the 60p video (as 2:2) and sent that as 120hz uncompressed to the TV and only the TV had good motion interpolation, that might cause problems for the motion interpolation in the TV (though I suppose it wouldn't matter when we get players that, as well as being able to pass 100/120hz video to the TV, also have a motion interpolation option in the player - if you wanted to use it).

Another way, using a cable/connector with less bandwidth could be to send two streams - one at 24p for the movie and one for the PiP commentary and have the TV itself could combine the 2 as a PiP. If that's possible. Though I suppose this would need more intelligence in the TV itself do the PiP (though some current TVs already have a PiP function).

So what else is new. Another thing HDMI is not so good at. If HDMI doesn't support this, then DisplayPort is standing by: http://www.displayport.org/white-papers/whitepapers/DP_Tech_Overview_English.pdf

Its spec already allows 120Hz, 1080p (at 12-bits per component no less).DisplayPort has a maximum bandwidth of 10.8 GBps but like HDMI/DVI it uses 8b/10b encoding (http://en.wikipedia.org/wiki/8b/10b_encoding). With a maximum video data rate of 8.64 GBps even with no blanking intervals 1080p120 at 36-bits per pixel would not be possible (8.95 GBps). Both HDMI 1.3 (8.16 GBps) and DisplayPort (8.64 GBps) though are technically capable of 1080p120 at 30-bits per pixel (7.46 GBps).

Also, though I agree we need better connections (better than current HDMI etc.) for sending 120hz video as well as higher res (like 4k), couldn't another alternative be sending dual streams to the TV via the HDMI (or better) connector).
Either way we need new TVs and players :). So as long as it gets done, it doesn't matter how.

If the player did the PiP and had the 24p video (as 5:5) and the 60p video (as 2:2) and sent that as 120hz uncompressed to the TV and only the TV had good motion interpolation, that might cause problems for the motion interpolation in the TV (though I suppose it wouldn't matter when we get players that, as well as being able to pass 100/120hz video to the TV, also have a motion interpolation option in the player - if you wanted to use it).
If done right, no processing occurs in the TV. The TV receives 120Hz video which happens to have one part of it changing faster than the other. It would be progressive video otherwise as far as it is concerned.

Another way, using a cable/connector with less bandwidth could be to send two streams - one at 24p for the movie and one for the PiP commentary and have the TV itself could combine the 2 as a PiP. If that's possible. Though I suppose this would need more intelligence in the TV itself do the PiP (though some current TVs already have a PiP function).
I think you already realized the complication with this :). You have to send all the intelligence to the TV together with timing and that would be a nightmare to get right. Best to leave the TV "dumb" and have the source do the right thing.

I agree (that it would probably be better to have the intelligence in the player).

Though I thought, using current TV's motion interpolation options (if I wanted to use it) it might need a change to their algorithms. If it was receiving a 120p signal it might have to check whether each 5 frames were identical (ie. it was really a 24p signal within a 120p one, rather than a different frame rate like 30p/60p or something else within the 120p signal) so it could more easily interpolate the actual 24p motion within the 120p signal. It might take a bit more processing work for the TV to do this than the player, which already knows that the original was 24p.

It might be even harder for the TV, when the motion interpolation option was on and it was receiving a 120p signal and the PiP commentary option was on, for it to know which bits of the picture were actually 24p and which were actually 60i/p (for better motion interpolation - when it was on).

So this is why it is probably better if this option, including a motion interpolation option is in the player (which I don't think any currently are :(). Also, I read about some new LCD HDTV (from Samsung) that can do 240hz motion interpolation! :)

DisplayPort has a maximum bandwidth of 10.8 GBps but like HDMI/DVI it uses 8b/10b encoding (http://en.wikipedia.org/wiki/8b/10b_encoding). With a maximum video data rate of 8.64 GBps even with no blanking intervals 1080p120 at 36-bits per pixel would not be possible (8.95 GBps). Both HDMI 1.3 (8.16 GBps) and DisplayPort (8.64 GBps) though are technically capable of 1080p120 at 30-bits per pixel (7.46 GBps).
36-bits? Where did you get that? Surely you know the difference between RGB/YUV and 4:4:4/4:2:0.....

If not, get a copy of WSR magazine a couple of issues back where I wrote a tutorial on this.

36-bits? Where did you get that?HDMI's Deep Color modes only allows for 4:4:4 (no chroma subsampling) though DisplayPort does allow for 4:2:2 YCbCr at any bit depth.


Surely you know the difference between RGB/YUV and 4:4:4/4:2:0.....Yes, though if you are referring to HDMI 1.3 and DisplayPort there is technically speaking only 4:4:4/4:2:2. Also HDMI 1.3 supports the xvYCC color space (http://en.wikipedia.org/wiki/XvYCC) which will hopefully be supported in future computers, game consoles, and video formats.


If not, get a copy of WSR magazine a couple of issues back where I wrote a tutorial on this.Which was a nice general article though for anyone wanting a detailed and free description on chroma subsampling (http://en.wikipedia.org/wiki/Chroma_subsampling) and color space (http://en.wikipedia.org/wiki/Color_space) I would recommend wikipedia.

HDMI's Deep Color modes only allows for 4:4:4 (no chroma subsampling) though DisplayPort does allow for 4:2:2 YCbCr at any bit depth.
So I say that DisplayPort supports 12-bit at 120Hz, and you come and say HDMI doesn't? And agree that DisplayPort does? :confused:

Who is on first again? :D

So I say that DisplayPort supports 12-bit at 120Hz, and you come and say HDMI doesn't?I originally thought you were referring to 36-bits per pixel since you said "120Hz, 1080p (at 12-bits per component no less)" with no mention of chroma subsampling. Also you compared DisplayPort to HDMI and I wanted to clarify what each could do which is why I posted about both.


And agree that DisplayPort does? :confused:For 12-bit 4:4:4 RGB/YCbCr 1080p120? No. For 12-bit 4:2:2 YCbCr 1080p120? Yes.

I originally thought you were referring to 36-bits per pixel since you said "120Hz, 1080p (at 12-bits per component no less)" with no mention of chroma subsampling.
And you have heard of how many consumer video delivery formats using 4:4:4? Hint: no answer is required :).

For 12-bit 4:4:4 RGB/YCbCr 1080p120? No. For 12-bit 4:2:2 YCbCr 1080p120? Yes.
Good grief....

And you have heard of how many consumer video delivery formats using 4:4:4?None, though I also haven't heard of any consumer video delivery formats that use more than 8-bit 4:2:0 YCbCr or displays that can accept a 1080p120 video signal so both of us are posting about the future. Personally I think computers and game consoles will be the first consumer products that truly make use of Deep Color (http://en.wikipedia.org/wiki/Deep_Color). For instance the PS3 was able to output at 30-bits per pixel back at a 2007 CES demonstration (http://www.hdmi.com/press/pr/pr_20070105.aspx) so I wouldn't be surprised with 36-bits per pixel output on the PS4 and Xbox 3. I think that might explain why we see the same phrase ("12-bits per component") so differently.

For instance the PS3 was able to output at 30-bits per pixel back at a 2007 CES demonstration so I wouldn't be surprised with 36-bits per pixel output on the PS4 and Xbox 3. I think that might explain why we see the same phrase ("12-bits per component") so differently.

Lack of ram is always an issue when games are being developed for consoles. Also using higher color depths will use significantly more fillrate. I'm willing to bet that most developers will trade off higher bit depth rendering for other features even if it's available.

Lack of ram is always an issue when games are being developed for consoles. Also using higher color depths will use significantly more fillrate. I'm willing to bet that most developers will trade off higher bit depth rendering for other features even if it's available.That is possible since it would be up to the game developer to decide whether it would be worth it. I would note though that Halo 3 was slightly less than 720p in resolution because of HDR lighting (http://www.joystiq.com/2007/10/01/bungie-halo-3-resolution-cut-for-hdr-lighting/) so I think that at least some of the major games will be capable of Deep Color output on the PS4 and Xbox 3.

Halo 3 was less then 720p for performance reasons. You can use HDR lighting at 720p. Bungie just chose to sacrifice resolution rather then frame rate. But yes, that's a good example of why deep color probably will not be used. Bungie would most likely have made the same decision to cut deep color for better performance as well. Avoiding the use of deep color would allow for a sizable performance boost over using it while delivering a comparable visual experience.

Deep color just isn't going to be the mind blowing experience for games many people think it will. In fact a developer would have to abandon all thier workstation monitors and video cards for ones that will display greater then 8bit per component color. I'm not sure many developers would spend that much for an incremental upgrade that many players will not be using. The 8bit environment has been used and optimized for a long long time. It's easier for movies because every existing piece of film is a source that already has a large enough gamut for deep color. Also the back end necessary for greater then 8 bit color already exists in Hollywood.

Halo 3 was less then 720p for performance reasons. You can use HDR lighting at 720p. Bungie just chose to sacrifice resolution rather then frame rate.Bungie said (http://www.joystiq.com/2007/10/01/bungie-halo-3-resolution-cut-for-hdr-lighting/) they were willing to have a lower resolution because they wanted HDR lighting in Halo 3.


Bungie would most likely have made the same decision to cut deep color for better performance as well.Note that rendering at a higher bit rate is one of the ways to get HDR lighting and all DirectX 9/10 GPUs support 64-bit rendering. Several current game engines support it including the Unreal 3 engine (http://www.unrealtechnology.com/features.php?ref=rendering):

"64-bit color high dynamic range (HDR) rendering pipeline. The gamma-correct, linear color space renderer provides for immaculate color precision while supporting a wide range of post-processing effects such as motion blur, depth of field, bloom, ambient occlusion and artist-defined materials"


Deep color just isn't going to be the mind blowing experience for games many people think it will.Going from 16-bit color to 24-bit color wasn't a "mind blowing experience" but few people would argue that it wasn't an improvement. In much the same way if Deep Color gives HDR lighting and better luma/color gradation I think it would be worth it.


In fact a developer would have to abandon all thier workstation monitors and video cards for ones that will display greater then 8bit per component color.Only the game developers who make the artwork in the game would need Deep Color displays and video cards. Also many recent NVIDIA and ATI video cards support 30-bit output such as the value range ATI HD 2400 (http://ati.amd.com/products/radeonhd2400/specs.html) (which you can get for under $50):

"Two integrated DVI display outputs
Primary supports 18-, 24-, and 30-bit digital displays at all resolutions up to 1920x1200 (single-link DVI) or 2560x1600 (dual-link DVI)1
Secondary supports 18-, 24-, and 30-bit digital displays at all resolutions up to 1920x1200 (single-link DVI only)1
Each includes a dual-link HDCP encoder with on-chip key storage for high resolution playback of protected content2
Two integrated 400 MHz 30-bit RAMDACs"

Bungie said (http://www.joystiq.com/2007/10/01/bungie-halo-3-resolution-cut-for-hdr-lighting/) they were willing to have a lower resolution because they wanted HDR lighting in Halo 3.

Unfortunately that's just Bungie making excuses. Call Of Duty 4 is 720P, 60fps and has HDR. (I think Halo 3 is great by the way, I'm not bashing it like it seems fashionable to do so, it was just a little disappointing graphically which was surprising since Halo 2 was one of the best looking games of the previous generation. :()

http://forum.beyond3d.com/showthread.php?p=1089950#post1089950

Call of Duty 4 is only 1024x600 as revealed by the same person that revealed that Halo 3 was only 1152x640. Both developers decided that a high frame rate was more important then raw resolution. This is the same developer mindset that will doom deep color not to be used even if it's available on next gen consoles.

http://forum.beyond3d.com/showthread.php?p=1089950#post1089950

Call of Duty 4 is only 1024x600 as revealed by the same person that revealed that Halo 3 was only 1152x640. Both developers decided that a high frame rate was more important then raw resolution. This is the same developer mindset that will doom deep color not to be used even if it's available on next gen consoles.

You know that guy just uses his TV and tries to count pixels and basically guesses the resolution don't you? :rolleyes: I think a better method would be to actually contact the developers and ask them what resolution their games run at.

You know that guy just uses his TV and tries to count pixels and basically guesses the resolution don't you?

He's using math to find out the correct answer. He is not guessing and has yet to be wrong about any game he has reported on.

His method:
In fact in being made, edge aliasing gives a lot of information about a game's native rendering resolution (thank aliasing, for once). All of the aliased steps are forced to make one native pixel height on horizontal edges (provided the edge isn't inclined +/- 45°) and one native pixel wide (+/- 45°) on vertical edges. From this axiom it's easy to determine a game's native resolution by determining the ratio of steps to screen pixels.
Here's his demonstration using a Halo 3 screenshot that he used when he outed Halo 3:
http://upsilandre.free.fr/images/Halo3nativereso.jpg

There is no guesswork involved, just basic math. Though if your understanding of math is weak, you might mistake it for guessing.

He's using math to find out the correct answer. He is not guessing and has yet to be wrong about any game he has reported on.

His method:

Here's his demonstration using a Halo 3 screenshot that he used when he outed Halo 3:
http://upsilandre.free.fr/images/Halo3nativereso.jpg

There is no guesswork involved, just basic math. Though if your understanding of math is weak, you might mistake it for guessing.

Well how do you account for when a game has more jaggies on some things than others? I seem to remember back when I was at Probe when the Saturn, Playstation and N64 were out the "jagginess" of things wasn't just down to resolution but also the size of the polygons in characters and backgrounds (like if they were made up of lots of little ones or a few big ones) and texture sizes too. If you stretch a small texture over a big polygon then the edges would surely be more jagged than if you used bigger textures on smaller polygons? It's been over 10 years since I last texture mapped but I'm pretty sure that's how things looked when I was doing it.

When you render to certain framebuffer size, the smallest change you can have on a diagonal edge less then 45 degrees is 1 pixel. Each diagonal edge less then 45 degrees is going to slope in 1 pixel increments. So look at a portion of a diagonal edge that is 32 pixels high (32 steps), when the original rendered image is remapped (scaled) to 1080p like the example, you are still only going to have 32 steps, but those 32 steps are stretched over more pixels (54) because it was scaled. The ratio of steps to the number of pixels it takes to represent them at the upscaled resolution allows you to determine the original rendering resolution. The original rendering resolution stays intact when you scale. Scaling does not magically make a image rendered at 640p have the edges that a natively rendered 720p or 1080p would have. Once you grasp the basis of how this works, it's easy for anyone to do it.

...before being recorded to tape. Once HDV recorded, it's 4:2:0, 1440x1080. So unless you're capturing from HDMI into a PC (i.e. Decklink), you're not getting that. Not to mention, even with pixel shifting tech, the imagers in that camera are 960x1080, not 1920x1080 native.
Yes, I'm aware of that. I was responding to the assertion that the video cameras were not natively capturing progressive footage.

As for 1440x1080, my understanding is that 1440x1080 uses a different pixel aspect ratio (PAR) as compared to 1920x1080. Many HD cameras store the captured HD image as 1440x1080 with a PAR of 1.33 and then a 1920x1080 PAR 1.2 image is extracted later in post. I understand this includes high-end broadcast/cinema Sony HD cameras.

I just ran some quick tests with Adobe Premiere Pro CS3 and Adobe Encore CS3 to see if I could author a 29.97p Blu-ray Disc. I captured a 29.97p HDV clip from a Sony HVR-V1U camera into an HDV 1440x1080 29.97p Premiere Pro project. I tried exporting the video as a 1440x1080 29.97p MPEG file and importing that into an Encore Blu-ray project. Encore only offered 29.976p, 29.97i, and 59.94p frame rates for a Blu-ray project, so I used 29.97i (for both this test and the other tests). I authored a Blu-ray folder, and used ReStream to look at the resulting .m2ts file. Neither the frames nor the sequence were marked as progressive, indicating Encore must have re-flagged and/or re-encoded the frames/stream, as the file exported from Premiere Pro had both attributes marked as progressive.

I also tried exporting directly into Encore from Premiere Pro using the integrated "Export to Encore" Premiere Pro module. I chose one of the 29.97i MPEG Blu-ray presets. ReStream showed the same results regarding the frame and sequence as with the above method.

A third method I tried was importing the captured HDV MPEG clip directly into Encore. With this method, ReStream showed some interesting results. The .m2ts file was marked as 1920x1080, instead of the 1440x1080 the above methods produced. And, the frame type was set to progressive and upper field first (the latter attribute the same as the first two tests). The interesting thing is that ReStream shows the original clip, as captured, is marked as 1440x1080 and does not have the progressive frame type set.

I last tried exporting a 1080x1920 29.97p MPEG file from Premiere Pro. I used ReStream to remove the progressive sequence flag and set the upper field first before importing the file into Encore. I left the progressive frame attribute in place. The resulting Blu-ray .m2ts file retained these attributes, including the progressive frame type.

EDIT: I should add, I have no idea if or how a Blu-ray Disc produced using one of the last two methods would play on a Blu-ray set-top player or in a computer Blu-ray drive, as I don't own either one at this time, much less a Blu-ray burner.