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post #1 of 12 Old 02-01-2012, 08:38 PM - Thread Starter
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I was looking on Amazon and saw that the Bond 50 box set is available for pre-order and it's 23 discs for 22 movies. Over the weekend I bought The Da Vinci Code and the extended cut of the film and special features are all on one disc. So this got me wondering how much footage can fit on to a single BD. I understand that there are single and dual layer discs, 25/50 GB of space, respectively. And I understand that movies have different average bit rates which can create a fluctuation in how many minutes can fit on to a disc. I read on Bluray.com (I think), in their "What is Blu Ray?" FAQ that a dual layer disc can hold 9 hours of footage, in HD, on a disc. So when I saw that Bond 50 probably has the feature film and all special features on a single disc, I was wondering if they were cutting on PQ and AQ to fit everything on to a single disc. Companies like to exaggerate of inflate specs of their products, so I half expect that 9 hours of HD video on a 50 GB BD wouldn't be the best you can get. What would be a reasonable amount of film length for a movie that deserves the highest picture and audio quality, i.e. James Bond, Star Wars, Lord of the Rings, etc.? Would there still be enough space for bonus features with the main feature? Both Star Wars and LOTR have their special features on a seperate disc, with the LOTR EE versions on 2 discs. I admit I've not checked to see whether they movies are on single or dual layer discs, but I would expect dual. Perhaps I'm still too used to the way DVD capacity is chosen.

So how long of a high quality feature film should be able to fit on a single blu ray disc?

Thanks in advance to all responses.
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post #2 of 12 Old 02-02-2012, 05:33 AM
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Quote:
Originally Posted by anikun07 View Post

So how long of a high quality feature film should be able to fit on a single blu ray disc?

It depends on bitrate used, and things really depend on quality of the source, and how easy it is to compress.

3 hours at avg 37 Mbps (video+audio tracks) would be about 48.77 GB
4 hours at avg 28 Mbps (video+audio tracks) would be about 49.21 GB
5 hours at avg 22 Mbps (video+audio tracks) would be about 48.33 GB
6 hours at avg 18.5 Mbps (video+audio tracks) would be about 48.77 GB
7 hours at avg 16 Mbps (video+audio tracks) would be about 49.21 GB
8 hours at avg 14 Mbps (video+audio tracks) would be about 49.22 GB
9 hours at avg 12.5 Mbps (video+audio tracks) would be about 49.44 GB

But quality will get worse the more hours you put on (with same codec). So for quality with the current codecs, I don't think they'd put much more than 4 hours of HD on a single BD50. Even less if 3D. And the studios need bitrate for the different audio/language tracks, especially in Europe. But the studios would be able to market using multiple discs more than single discs to hold many hours of content, or would be much more likely to.
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post #3 of 12 Old 02-02-2012, 05:49 PM
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bitrate*runtime/8=movie size in bytes

The first example above:
37Mbps*10800/8=49950MByte=48.78GB

From the specs thread:
[US] 2001 The Lord of the Rings: The Fellowship of the Ring 23.32Mbps 2:58:24 39,233,193,984 movie size

23.32*10704/8=31202.16MByte quite a bit of discrepancy?

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post #4 of 12 Old 02-02-2012, 08:03 PM - Thread Starter
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Thanks, I was really wondering about this. I'm very curious to see what the specs of the movies for the Bond 50 box set will be.
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post #5 of 12 Old 02-02-2012, 09:06 PM
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Quote:
Originally Posted by Kilian.ca View Post

From the specs thread:
[US] 2001 The Lord of the Rings: The Fellowship of the Ring 23.32Mbps 2:58:24 39,233,193,984 movie size

23.32*10704/8=31202.16MByte quite a bit of discrepancy?

That's the number for the video track only. 29.32 is what you need to get the correct movie size.
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post #6 of 12 Old 02-02-2012, 11:59 PM
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Quote:
Originally Posted by anikun07 View Post

I'm very curious to see what the specs of the movies for the Bond 50 box set will be.

Most if not all of the ones that have been released should be in the specs thread. I doubt these will be re-encoded: there might be some discussions in the Bond 50 thread. The ones that aren't out yet no one knows until they're out.

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Originally Posted by msgohan View Post

That's the number for the video track only.

Ah, ok thanks. Makes more sense to me to display the video instead of movie size as this is what people want to compare. It gives a heightened sense of reality when in the above example of BD50, only 31GB is actual primary video.

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post #7 of 12 Old 02-03-2012, 05:56 AM
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Sorry to throw a monkey wrench in the simple math being used here, but Blu-ray compression uses variable bit rate (VBR) encoding. Although you can guess, you never know the actual average bit rate or the total number of bits until it's done. By the same token, an average bit rate for one film has no bearing on that of another.

Instead of reciting meaningless scalar numbers, how about giving due credit to the hard working mastering artist-engineers who make the best use of what they have to work with?

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post #8 of 12 Old 02-03-2012, 07:02 AM
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Quote:
Originally Posted by Speed Daemon View Post

Sorry to throw a monkey wrench in the simple math being used here, but Blu-ray compression uses variable bit rate (VBR) encoding. Although you can guess, you never know the actual average bit rate or the total number of bits until it's done.

Yes I know Blu-ray can use variable bitrate (or constant bitrate - there's no rule saying they can't use CBR). So? I gave average figures and approx file sizes based on those and the duration. Average figures don't mean constant, or fixed bitrate, they mean average (average for the whole duration), so are correct for titles that use variable bitrate too (which I'd expect are the majority).
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Instead of reciting meaningless scalar numbers, how about giving due credit to the hard working mastering artist-engineers who make the best use of what they have to work with?

If you want to use better maths or give a better answer to the OP's question go ahead. Yes, what the person doing the encoding does will have an affect on the quality that can be achieved for a particular source, but so does available disc space (or actual disc space used), and bitrate. Disc space and bitrate, etc. have a bearing on the amount (duration) of 'quality' HD content that can be stored (as welll as what the encoder does, also also taking into account all the other things I mentioned like quality of source, etc.).

The OP asks a valid question about amount of 'quality' HD that can be stored on a 50GB discs, etc. Saying "give credit to the hard-working artists-engineers" doesn't answer that question. If studios could easily create many hours (eg. >=9) of 'full quality' HD on a single BD50 using current Blu-ray codecs there'd be no real need (picture quality wise.) for multiple discs for a particular title. But bitrate/disc space does limit/affect quality that the studios can produce.
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post #9 of 12 Old 02-03-2012, 02:44 PM - Thread Starter
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Thanks for the replies, everyone. Yeah, my main question, that I understand now, was how long could a movie be before the special features would cause a decrease in available disc space for the main feature. I understand that there are many variables, but for movies that we would expect at or near reference quality, would a movie have plenty of room left for special features. Certain movies have several hours of video not using the main film, I.e. commentary.

So a 2 hr. movie with 10 hours of interviews and documentaries would other have to reduced average bit rate of the movie or the special features. Although I have noticed that most features are only 480 i or p and 2.0 ch audio. So that does allow for an increase in special features run time.
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post #10 of 12 Old 02-05-2012, 04:05 AM
 
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Quote:
Originally Posted by anikun07 View Post

Thanks for the replies, everyone. Yeah, my main question, that I understand now, was how long could a movie be before the special features would cause a decrease in available disc space for the main feature. I understand that there are many variables, but for movies that we would expect at or near reference quality, would a movie have plenty of room left for special features. Certain movies have several hours of video not using the main film, I.e. commentary.

So a 2 hr. movie with 10 hours of interviews and documentaries would other have to reduced average bit rate of the movie or the special features. Although I have noticed that most features are only 480 i or p and 2.0 ch audio. So that does allow for an increase in special features run time.

Anything over three hours should be on two discs extras or not.
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post #11 of 12 Old 06-24-2012, 08:48 AM
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Whatever happend to the proposed increased storage size on a dual layer disc to about 66GB? I remember reading about that a number of years ago. There was also talk of an increase to about 54GB, which could be achieved a little more easily.
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post #12 of 12 Old 06-24-2012, 10:12 AM
 
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Originally Posted by RWetmore View Post

Whatever happend to the proposed increased storage size on a dual layer disc to about 66GB? I remember reading about that a number of years ago. There was also talk of an increase to about 54GB, which could be achieved a little more easily.

Nothing. Sony and Panasonic went public in January 2010 with their Maximum Likelihood Sequence Estimation evaluation index

http://www.engadget.com/2010/01/02/new-standard-could-pave-way-for-higher-capacity-blu-ray-discs/

Based on what Andy Parsons of the BDA just said a week ago, it appears that 50GB is "good enough"
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Parsons: We are already at the maximum resolution available for the HDTV systems currently in use around the world (1080p), so the only way to become “more high def” would be to incorporate 4K resolution into the format. At present, the BDA is not working on a 4K version of Blu-ray, but if and when the time comes to do that, we believe the 50GB capacity should allow us to accommodate the much higher data rates that 4K sources require.
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