Ask questions to BD authoring and compression insider "2themax"

[2themax]

Originally Posted by owa

Do you know if that (buffer fill rate) is why the PS3 bitrate meter sometimes jumps above 40 (briefly) or is that just an accuracy issue.

It's a mix of both.

[Chris Beveridge]

Originally Posted by 2themax

It's a mix of both.

I've noticed this far more with my Japanese authored BD release than with my US authored ones. Bandai Visual Japan comes to mind with it. They're consistently in the thirties with AVC bitrates and have those leaps into the 40's somewhat regularly.

[owa]

Originally Posted by 2themax

It's a mix of both.

Thanks for the info.

[patrick99]

Originally Posted by 2themax

We'll definitely see someone market "Superbit" one day. Some of the current releases are "Superbits" as they are. Simpsons comes to mind first.

Having a continuous bit rate may actually lower quality. Besides bit rate, there's buffer fill rate. That can allow for a quick peak above 40Mbps. I've seen my own work hit 49-50Mbps for a very short period.

Am I being overly cynical in thinking that some studios might be deliberately restricting the bitrates on current releases with the intention of releasing "Superbit" versions in the future and wanting to ensure that there will be a noticeable PQ improvement when they do?

[CptGreedle]

Hi 2themax!
I have some questions about authoring... afraid to hear what the answer is but I need to know.

I am an animator and am planning to make a series of short animations in both 2D and 3D. I also work mainly on a mac, but i do have access to a pc.
The first thing I want to know is about BD9. Is it possible to create a BD9 disc using DVDs and DVD burning software/hardware? What software do you recommend and is there any on the mac that is sufficient or do I have to resort to the pc?
Is the bitrate of a BD9 the same as a BD25/BD50?
Is the BD-J the same as well?
How long would an average film on a BD9 be?
Do I need to pay licensing rights (or other fees) to release a limited line of BD25 films? How much? And would I have to do the same for BD9?

I am so sorry with all these question... I have been looking all over the internet for info on the BD9 but it is very limited, and it seems that although it is a valid format, it is not used. It's hard for a small-time production studio to release HD content right now isn't it?

Thanks for looking at my post.

[Icemage]

Originally Posted by 2themax

Having a continuous bit rate may actually lower quality. Besides bit rate, there's buffer fill rate. That can allow for a quick peak above 40Mbps. I've seen my own work hit 49-50Mbps for a very short period.

So it's actually possible to budget in some extra bits to cover an action scene without breaking the player hardware?

I've seen the bitrate meter on my PS3 rise above 40Mbps in a few cases (Open Season comes to mind, as does The Prestige) - even accounting for the inaccuracy of the bitrate meter, are these likely examples of what you're talking about?

[2themax]

Originally Posted by patrick99

Am I being overly cynical in thinking that some studios might be deliberately restricting the bitrates on current releases with the intention of releasing "Superbit" versions in the future and wanting to ensure that there will be a noticeable PQ improvement when they do?

Maybe a bit. Warner has the best chance to do this since the encodes have been ports from the HD-DVD versions and a Blu-ray encode will literally be a "Superbit" in comparison.

[2themax]

Originally Posted by CptGreedle

Hi 2themax!
I have some questions about authoring... afraid to hear what the answer is but I need to know.

I am an animator and am planning to make a series of short animations in both 2D and 3D. I also work mainly on a mac, but i do have access to a pc.
The first thing I want to know is about BD9. Is it possible to create a BD9 disc using DVDs and DVD burning software/hardware? What software do you recommend and is there any on the mac that is sufficient or do I have to resort to the pc?
Is the bitrate of a BD9 the same as a BD25/BD50?
Is the BD-J the same as well?
How long would an average film on a BD9 be?
Do I need to pay licensing rights (or other fees) to release a limited line of BD25 films? How much? And would I have to do the same for BD9?

I am so sorry with all these question... I have been looking all over the internet for info on the BD9 but it is very limited, and it seems that although it is a valid format, it is not used. It's hard for a small-time production studio to release HD content right now isn't it?

Thanks for looking at my post.

I hate to say it, but the answers as a whole aren't good. Mac just isn't BD ready at this point. Encore is the most advanced BD authoring program for the Mac and it just doesn't cut it. It's not much better in the PC world yet either. For anything even semi-professional, it will have to be done with either Blu-print or Scenarist.

BD-9 isn't just a small BD-25. There are further restrictions on the bit rates. I don't know off the top of my head, but I'd guess the max mux rate is under 30Mbps, versus 48Mpbs on regular BD. The authoring, HDMV or BD-J, will remain the same as far as I know. Run times are a hard guess without knowing audio or content restrictions.

The main licensing on any BD is AACS. There's fees for being a content provider, fees for making a master, and fees for every disc that is made and that's just the stuff you'd see as the publisher of the content. Replicators have their own set. The per master fee is $1500-2200 and the per disc cost is $.03-$.04 (don't quote me on that). I don't know the fee for being a content provider, but I heard it was substantial.

[fitprod]

Originally Posted by 2themax

BD-9 isn't just a small BD-25. There are further restrictions on the bit rates. I don't know off the top of my head, but I'd guess the max mux rate is under 30Mbps, versus 48Mpbs on regular BD. The authoring, HDMV or BD-J, will remain the same as far as I know. Run times are a hard guess without knowing audio or content restrictions.

I thought the max bit rate on DVD was 10Mbps.

fitprod

[2themax]

Originally Posted by Icemage

So it's actually possible to budget in some extra bits to cover an action scene without breaking the player hardware?

Yes, but not in the sense that I think you are asking. If you did it for a an entire scene, you'd run into the same problems are using a constant bit rate. Think of it more along the lines of being used if there was a shot with quick motion or an explosion.

I've seen the bitrate meter on my PS3 rise above 40Mbps in a few cases (Open Season comes to mind, as does The Prestige) - even accounting for the inaccuracy of the bitrate meter, are these likely examples of what you're talking about?

Yes. They should be very short lived though.

[2themax]

Originally Posted by fitprod

I thought the max bit rate on DVD was 10Mbps.

fitprod

That's at 1x. For reference, HD-DVD on DVD was done at 3x, 30Mbps. I am assuming the same for BD.

[Icemage]

Originally Posted by 2themax

Yes, but not in the sense that I think you are asking. If you did it for a an entire scene, you'd run into the same problems are using a constant bit rate. Think of it more along the lines of being used if there was a shot with quick motion or an explosion.

That was exactly what I was referring to - really, really brief high intensity scenes like a fast camera pan or a large explosion. If I understand this correctly, you could try to ease off on the buffer by making use of B/P frames right before the high-intensity scene, then make use of the available extra overhead and use some extra I-frames to cover the trouble spot so your quantization levels don't go out the window (so you're actually reading data out of the buffer faster than it's coming off of the Blu-ray disc, if only for a moment, and even there you wouldn't be able to sustain it for more than a small number of frames).

Is that sort of how it works? If so, it seems like this would be a pretty work-intensive process, as you'd have to micromanage the encoding process on a nearly frame-by-frame basis for this. Are there tools in place to handle this sort of thing on a more routine basis in the existing encoding suites you've worked with?

[2themax]

Originally Posted by Icemage

That was exactly what I was referring to - really, really brief high intensity scenes like a fast camera pan or a large explosion. If I understand this correctly, you could try to ease off on the buffer by making use of B/P frames right before the high-intensity scene, then make use of the available extra overhead and use some extra I-frames to cover the trouble spot so your quantization levels don't go out the window (so you're actually reading data out of the buffer faster than it's coming off of the Blu-ray disc, if only for a moment, and even there you wouldn't be able to sustain it for more than a small number of frames).

You've hit the nail on the head. I went through that process just recently with some concert footage.

Is that sort of how it works? If so, it seems like this would be a pretty work-intensive process, as you'd have to micromanage the encoding process on a nearly frame-by-frame basis for this. Are there tools in place to handle this sort of thing on a more routine basis in the existing encoding suites you've worked with?

The better encoders can manage this and it is a very intensive process. CineVision PSE does it and you can go frame-by-frame if you so desired. And even that is only a small portion of the available options to control the bit usage.

[dialog_gvf]

Is this a compression effort/time issue, or is the momentary extra bandwidth really needed?

Gary

[2themax]

Originally Posted by dialog_gvf

Is this a compression effort/time issue, or is the momentary extra bandwidth really needed?

Gary

It is definitely needed. It has zero to do with effort or time and everything to do with quality. Also, the compressionist isn't allowed to specify the rate to go above the peak rate, in this case 40Mbps. The encoder handles that.

[FourToedStatue]

Hi 2themax,

Will you know before most when Universal starts readying their titles and will you be able/allowed to even hint at it here when it happens?

Thanks!

[dialog_gvf]

Originally Posted by 2themax

It is definitely needed. It has zero to do with effort or time and everything to do with quality. Also, the compressionist isn't allowed to specify the rate to go above the peak rate, in this case 40Mbps. The encoder handles that.

Interesting. You do realize how explosive such a statement would have been a year ago?

Gary

[patrick99]

Originally Posted by 2themax

Maybe a bit. Warner has the best chance to do this since the encodes have been ports from the HD-DVD versions and a Blu-ray encode will literally be a "Superbit" in comparison.

Actually Warner wasn't among the studios I was thinking of, but now that you mention them, it is true that they were using bitrates that didn't even come close to what the HD DVD specs allowed, so perhaps they did have this in mind. . .

[CptGreedle]

Thanks for that update 2themax.
Well I guess right now I will just have to wait and see what will come out for BD-authoring in 2009.
As far as fees go, I will have to do further investigation later on the requirements and the like for a BD disc. If I can avoid using AACS, I don't mind loosing the protection. I suppose I will also have to play with BD9 rates and runtime.
But it might just end up that I will be restricted to internet downloads and SD DVDs until the prices drop more.
Thanks again for your timely and very helpful response.

[2themax]

Originally Posted by JackBauer24

Hi 2themax,

Will you know before most when Universal starts readying their titles and will you be able/allowed to even hint at it here when it happens?

Thanks!

I couldn't answer that even if I knew, but I'd assume they are working through the technical aspect of the BD spec. Universal did HD-DVD justice and used every option they could. Let's hope they do the same with Blu-ray.