The third edition and it’s predecessors have always been required reading for all new staff here at    24-7DVD!

This book, running at 700 pages and written by Jim Taylor, the author of the Internet DVD FAQ, covers everything from the history of the format to the in’s and outs of the technology.   Always good as a crash course or dip in reference guide, this is one book that everyone should have access to.

New and used always available on Amazon… get your hands on one!

The Digital Bits: Insider’s Guide to DVD

Written by the team behind one of the original DVD websites, this book offers an easy to follow history of the format, along with a collection of reviews of ‘must have’ titles.

Where this book is worth it’s weight in DVD gold is in it’s coverage of the creation of the Alien Quadrilogy box set.  If you’ve ever wondered what work goes into a high profile Hollywood title, this is the book to read.

Why Not?

DVD was not designed to interact with the internet.  Although DVD has been an incredibly popular format, it is easy to forget how ‘old’ it is.   Web connectivity never was part of the DVD Specification.  The blueprint to which all DVD players must follow was set in stone in 1995, and there is no real way to change that without breaking every DVD player that has come before it.

But what about products like Spruce Convergence, DVD@ccess and eDVD?

Three major industry players in DVD authoring have come up with products that attempted to offer web usability to DVD:

In August 1999 Spruce Technologies introduced a product called Spruce Convergence, an add-on for their Authoring Applications to add “full-duplex communication between DVD-based video and the Web, allowing web pages to be invoked directly by button clicks on the DVD title, as well as letting the internet browser control the DVD video.”  Spruce were later bought out by Apple, who went on to release it as DVD Studio Pro Version 2.

By 2002, Apple’s DVD Studio Pro 1.5 had a feature known as DVD@CCESS Web.  This functionality continued through later versions based on Apple’s aquisition of Spruce, but did not offer the same flexibility.   Like Spruce, this offered the ability to add a huperlink to a button on a DVD Page, but only if the disc was played back in Apple’s DVD Software.  This made the function inaccessible for PC users and therefore, arguably, the majority of corporate DVD creators.

At the same time, Hollywood also experimented with the concept of Web enabled DVDs, using InterActual’s PC Friendly Software.  A number high profile titles were produced over the years, including the early Harry Potter chapters and The Matrix.  Features included script viewers, storyboard comparisons, Image Galleries and QucktimeVR viewers.

Today, when viewing the InterActual website, it appears that no major titles have been announced since 2007.

Sonic Solutions, the company behind the Scenarist Professional DVD Authoring product, bought InterActual in 2004, and went on to release a number of versions of it’s eDVD software, which was designed to allow the easy addition of weblinks to DVD VIDEO discs.  Again, there was a requirement to install a compatible DVD software player on your PC or Mac, but at least the rationale was that more users would already have this installed as it had been used on so many high profile Hollywood titles.

Unfortunately, the InterActual player was never upgraded to support Windows Vista (and now Windows 7), and no option on the market dealt with the set-top box environment of the home.

So what are my options?

There are various other ways to direct your viewers to your web site:

1. Include your web address on the screen and it can be copied into a browser  on your laptop, PC or phone.  (It sounds old fashioned, it is old fashioned).  This is ideal if your web address is short or memorable.
2. Include a local web page on the DVD as ROM content.  This will not be accessible from a DVD player but PC users can find the file in the route of the disc and be re-directed from there.  This is not a retail solution as this method might be too complicated for ‘average’ users.
3. For some projects a two disc set featuring a CD Rom and a DVD would provide the solution.  The DVD for the high quality video files and the CDROM for any supporting documents including PDFs, links and Office documents for download.

How about Blu-ray?

Well, you can have Internet connected discs, marketed as “BD Live”, which when used in conjunction with an internet-connected “BD Live” compatible Blu-ray player will access online content…

But …This content is stored and distributed by the content owner, in the form of trailers and “BD-J” java applications.  This is NOT a web browser to link to any website you wish.  BD Live allows access to Blu-ray specific online content, and nothing more.

This means you can include your target URL to be copied down and typed into a browser, your PC must have a Blu-ray drive to acces BD-Live content or you can include a CD Rom in the package.

What a good idea!

Click here for the link

Often you will find on the packaging of blank media a duration of some sort. This is partly a throwback to the days of CD-Rs where the duration given was in fact how much Audio you could record to the disc. Audio has a fixed data rate and so there was always a direct relationship between the size of the disc (650Mb, 700Mb) and the amount of CD Audio you store (74 minutes, 80 minutes). With DVD VIDEO the data rate is variable and so when a blank DVD suggests a running time, this is usually based on a generic “quality” setting on set-top DVD Recorders – EP, SP, LP, HQ, SHQ etc. which are consumer speak for average data rates.

In actual fact, the easiest way to look at a DVD (or any kind of media) is as a ‘bit bucket’ – an object which can hold a certain amount of bits of Data. You have a certain amount of information you want to include on the disc and so you have to do a bit budget. It’s not different from doing any sort of budget.

There are probably lots of different ways to calculate a bit budget for a project, but the following was the way I was originally taught, using figures I was originally told. At some point, someone probably read them in either DVD Demystified or some other user guide…

A single-sided, single layer DVD (also known as a DVD-5) contains 36,096 Megabits of space (taking into account a little bit of headroom). Note that the value is Megabits not Megabytes. We use this measurement as we wish to calculate how many Megabits per second we have to describe our video.

A single-sided, dual layered DVD (DVD-9) contains 65,280 Megabits of space.

The first thing we need to do is add up the durations of all our footage (If you’ve only got a couple of moving menus, we ignore these as we’ll be rounding down figures for safety). Next, we need to convert this duration into seconds.

Let’s say we have 2 hours of footage to go on a DVD-5.

1. 120 minutes x 60 seconds = 7200 seconds of content.

Our audio is at a constant rate, so for example if we have 1 Dolby Digital audio track at 224Kbps:

2. 0.224 Megabits per second multiplied by 7200 seconds = 1612.8 Megabits just for the Audio.
3. 36096 Megabits minus 1612.8 Megabits = 34483.2 Megabits left over for our Video.
4. 34483.2 Megabits divided by 7200 seconds = 4.7893 Megabits per second.

So our average bit rate for our Video should be 4.7Mbps. If we were doing a CBR (Constant Bit Rate) encode that would be it, but you should get far better quality if you do a VBR (Variable Bit Rate) encode, which means that as long as the average across the length of the footage is 4.7Mbps, the encoder can go higher when it needs to compress really tricky video, it then needs to go lower at the easy bits to make savings in the budget.

For a VBR encode, you need to be able to tell your encoder what it’s peak or maximum bit rate is. The DVD VIDEO specification says that your combined Video and Audio cannot go any higher than 9.8Mbps, in which case your maximum Video bit rate would be 9.8Mbps minus your audio (0.224 Mbps) giving you 9.576Mbps for this example. Personally, I would never go above 9Mbps, and on a lot of titles will set my maximum to 8.5Mbps. The fact of the matter is you don’t know what kind of player you will be playing your disc back on, and some cheaper / older players might struggle if you max out your video encoding. Far better to have a safety margin than an issue with a title, because quoting the specification will fall on deaf ears at that point…

Remember that the data rate of your audio will vary depending on how many audio tracks you include, and what type of audio they produce. A number of encoders produce PCM audio by default which in an uncompressed state can take the best part of 1.7Mbps of space. Had we used PCM audio on the above job we would have given you an average video bit rate of 3.3Mbps.

So, the question is, how much of a fan are you? Take this test to find out….

1. You’d rather not lend DVDs to friends or colleague/ Even when you do, you never lend it in it’s original packaging.

2. You check out photos of people’s DVD collections online.

3. You’ve catalogued your DVD collection.

4. You’ve swapped out all of your Warner Bros titles into normal DVD cases because of your rational hatred for “snappers”.

5. No ordinary DVD will do, it has to be an Amaray branded DVD case – ying / yang release hub all the way!

6. When you pick up a DVD in the shops, you check to see if the first run had a coloured DVD case.

7. In a land of multi-region DVD Players, you check out DVDCompare.net before making a purchase.

8. If all versions are the same, you look out the one with the best packaging. Is there a steelbook version available somewhere?

9. You own one or more of the 20th Century Fox ‘head’ collections

10. If you do not like the official DVD cover artwork, you will look out alternatives – has bunnydojo done a version?

But what exactly does this data rate equate to in terms of picture quality?

The first thing to remember is that no matter what bit rate you give your footage, it will never look better than the source – the saying goes “garbage in, garbage out”, although sometimes more colourful terms are used. If you have shot your footage on a low quality camcorder, or worse VHS, then it doesn’t matter if you give it 9Mbps on a dual layered disc, it’s never going to look as something shot on a professional tape format or, better still, film. Ultimately, the best you can hope to achieve is an encode that is “transparent to master”.

The main strength in MPEG-2 compression for DVD comes from it’s use of Interpicture Compression, that is the differences between each picture. Because of the way MPEG-2 compression works, only every 12th or 15th picture is stored as an entire image. For the remaining pictures, only the differences between each image are stored.

In MPEG terms, you have what is known as a GOP or Group of Pictures:

I B B P B B P B B P B B P B B

The ‘I’ Frame is your only ‘whole’ picture of information, and provides your random access points (chapters etc). The remaining frames only contain information about the pixels that have changed.

The ‘P’ Frame is a ‘predicted’ picture, based on information from previous I and P frames.

The ‘B’ Frame is a ‘bi-directionally predicted’ picture, based on past and future frames.

Without going into too much detail, the ease of encoding your footage is down to the content – if there is a lot of fast or erratic motion – fire, water, smoke, hand held footage etc – then it is harder to compress as the changes between each picture are so much bigger and less predictable. If your footage is ’slower’ and ‘more sedate’ such as talking heads and landscapes then the changes between each frame are far less, and more predictable and so are easier to compress.

Taking this into account, if you have a low bit rate, then you are more likely to see ‘compression artifacts’ is hard to compress footage.

So, when you look at your footage and you look at your bit rate, think to yourself:

• Talking heads, not much motion at 4-5+ Mbps – I should be ok.
• Lots of fast moving action at 4-5 Mbps – That could look compresed.
• Lost of fast moving action at 6-7+Mbps – I should be ok.
• Anything less than 4Mbps – I might be trying to get too much on my DVD…