Long DVDs, What Bit Rate?

[Peter Riding]

Thought I'd post this question here rather than in specific software rooms as the wedding folks are far more likely to regularly produce long DVDs.

Most of my shows are around 45 to 60 minutes long so there is not an issue with fitting onto one DVD and using high bit rates for it.

I have several queuing up now which are around 2 hours each. I've been experimenting with Variable Bit Rate figures from bitrate calculators but the figures are coming out pretty low.

1) Should I be concerned that the VBR figures might be Max under 6,000,000 Average under 3,500,000 and minimum as low as 192,000 (Vegas Pro 11 defaults to a rather large 9,500,000 / 6,000,000 / 192,000)

2) Do you have your own preferred bit rate settings that you are happy to use to get long shows onto single discs for wedding work, that you are willing to share?

3) Do you ever use two pass variable bit rate? I understand that the file sizes can be significantly smaller than single pass but it does of course take a lot longer.

Thanks.

Pete

[Greg Clark]

Pete for me 70 minutes is my max. Anything longer the quality decreases and more customers cannot play their DVD.

[Don Bloom]

I routinely do between 90 and 120 minutes on DVD with no issues in either quality or playability. I use Vegas to render and DVDArchitect to author and burn.
For a 120 minute project I suggest the following bitrates:
MAX:8,000,000
AVERAGE: 4,826,000
MINIMUM: 2,000,000

These are assuming you are using AC3 audio.
Also VBR of course. One or two pass is your choice.

I have burned literally 1000's of DVDs using settings like this over the years, be it weddings or seminars or talking heads or web-a-mercials and I can turthfully tell you that I haven't had a single problem with a DVD. Not One! I do use TY watershield discs.

Edward Troxel has a newletter on his site (www.jetdv.com) that has a very good and accurate bitrate chart in it. I've been using it ever since he published it in June of 2003. AAMOF it's Vol 1. No. 7
2 hours with good quality isn't a problem so you should be fine with the results. Of course it might be a little less quality than a 45 minute product but frankly I don't anyone but you might see the difference.

[Dustin Moore]

A two-hour DVD on a 4.7GB blank is reasonable with two-pass if the
original footage is not overly noisy and not high-motion like sports.

The Sony Mainconcept codec is acceptable but you will get a noticeably
better result if you use the Cinemacraft basic encoder properly.

There is not a compatibility issue with lower rate media any more than
a regular constant bit rate video. Most problems come from low quality
media or using a burner in a way that produces high PI/PO error rates.

[Jeff Harper]

It is simpler for me to use printable dual-layer discs rather than to reduce quality settings.

I often lower bit rates when cutting it close, but unlike others I can absolutely see a difference in quality when trying to put more than around 1:40 on a disc. It's not much at first but the lower the bit rate, the lower the quality. It may even be imperceptible to some, but I don't like to push it.

I spend a lot on lenses, on cameras, and everything else, trying to achieve the best quality I can, and it feels wrong for me to lower quality settings at the last stage, doesn't make sense to me.

Even if it is not significantly better, I just feel better using the default bit rates.

Dual layer discs cost more, sure, and they burn at half the speed of single layer discs, but since I started using them life seems simpler, and I would never go back. I use single layers when it fits, if not I just use dual-layer and that's the end of it.

[Chad Whelan]

I will agree with Jeff that dual layers are the best option in my opinion for anything close to 2 hours. I also always use 2 pass VBR.

[Peter Riding]

Thanks for the suggestions and explanations folks :- ) I had overlooked using dual layer discs as I had though they are not widely compatible but it seems they are. So I shall go that route.

Don, I'm interested in your settings as I could not use figures as high as that. I've not been doing separate AC3 audio tracks but rather letting DVDa or Vegas Pro recompress on the basis that wedding audio is what it is and is seldom going to be pristine anyway.

However I just tested one particular show which is 1hr55mins long. I rendered audio only using both the Dolby Pro and the Dolby Studio templates at their defaults and both audio file sizes came in at 158mb. I then rendered using one of the Mainconcept templates for PAL widescreen and simly deselected the video in that tab and selected audio in its tab to get an audio only track. It came in at 185mb. So only about 30mb difference in file sizes. Yet Edward T's chart - which I had actually printed off ages ago - recommends a very substantial difference in max bit rates at 120 minutes, being 4826 for AC3 and 3451 for PCM. But thanks for taking the time to respond in detail, I do appreciate it.

Pete

[Dustin Moore]

Which media are people using for Dual Layer these days? I have more concerns
about compatibility with dual layer than with variable bit rate since years ago
there was a lot of discussions about dual layer. I'm willing to test though.

So far the best DVD-Rs that I've burned in my life have come from a Pioneer 206 blueray
burner and the usual 8x single layer Taiyo Yuden premium line. The PI/PO rates from
this combination are virtually perfect.

[Tom Hardwick]

Originally Posted by Greg Clark

Pete for me 70 minutes is my max. Anything longer the quality decreases and more customers cannot play their DVD.

This 'cannot play their DVD' doesn't make sense Greg. The greater the compression the *easier* it is for DVD players to recover the information. In other words a 2 hr film on a DVD-R is recorded at something like 4 mbps whereas a 1 hr film uses a far higher 8 mbps - and this is much tougher for any DVD player to read.

tom.

[Jeff Harper]

Ritek Ridata DRD+858-RDIWN-CB50, Dual Layer, DL, Double Layer, DVD+R, 8X, White Inkjet Hub Printable, Blank Media Discs, DRD+858-RDIWN-CB25

[Eric Olson]

Standard definition digital television typically uses an mpeg2 bitrate of 3.5mbps. Some of it looks great and some of it looks horrible. At lower bit rates the quality depends on the compressibility of the source and the efficiency of the encoder. Note that

1. Sensor noise and film grain are difficult to compress.
2. Progressive 24p footage is easier to compress than 60i.
3. The encoders that come with most NLEs are not very efficient.

If you shoot noise-free 24p and use a high efficiency encoder, then it is quite possible to master a high quality 2 hour single layer DVD.

[Chris Harding]

Hi Guys

I still use two disks if the wedding is a largish one and I have more than just the ceremony...I think a double disk set looks like better value for money than trying to cram everything onto a single disk at a lower bitrate or using a real slow burning dual layer disk!!

I wouldn't worry too much about the max bitrate (or the min) in Vegas...I keep the average for weddings on 6000 and 99.99% and within a few points of 6000..I have yet to see a clip that's higher than 6010!!! They tend to be in the 5990 to 6005 range!!

Weddings are slow moving events so I also tend to only do a single pass and certainly have never had any complaints about bit rate or quality. Would the client seriously spot the difference between a one and two pass??

If you want to get the absolute max quality and fit it on a single disk then use a bitrate calculator but I seriously think that providing dual disk sets is a better marketing ploy and costs you very little extra!!

Chris

[Tim Bakland]

Dual layer all the way! The price is hardly different (plus, how many copies are we talking for events like weddings -- it's a negligible difference). And Chris: you mention "slower burning" -- but shouldn't be be burning at slow speeds anyway?

By the way: haven't any *any* compatibility issues with dual layer DVDs in the 5 years I've used them.

[Chris Harding]

Hi Tim

The best we can get here in Dual Layer is 4X and they are unreliable unless you burn them at 1 X!!!
I only supply 3 x DVD sets but DL cost me around $3.00 each compared to single layer at 0.36c each.

I have had issues when I swopped media brands so I also stick rigidly to LG media with my LG drives and never had an issue....I changed media last November foolishly and all the wheels fell off....it wasn't the cost of replacing media but simply the time to re-burn and drive back to the client uttering huge apologies!!!

Besides as already mentioned, my brides seem to think that it's great that they get a DOUBLE DVD set.. makes it seem better value for money in their eyes???? Single and double cases cost me the same and there is still only one sleeve to print.

I probably could get DL media that's good but I really don't want to go thru the nightmare of brides being bitter and twisted when all the family are assembled in the living room and the DVD doesn't work on their Sony player!!!

With my luck Murphy's Law would definately apply and the faulty DL disk would be a bride where I would have to drive an hour there and back!!! I prefer to play it safe !!!

Chris

[Peter Riding]

Thanks for all that valuable feedback.

I had to get a project completed and out the door before my dual layer discs will arrive. I used max 6,000,000 av 4,200,000, min 2,000,000 and did 2-pass It came in at 4.16GB ( or 4,471,828,480 by the alternative criteria). So still not within the figures Don is achieving. It fits on a DVD as a straight burn but Vegas Pro rejects it as too big if I try to burn a compliant DVD within that program, even if I ignore its warnings and get as far as I can. DVD Architect Pro also required it to be shrunk but not by much. In doing this I discovered that my previous render setting of Min 192,000 (the Vegas default for Min) was too low as DVDa could not then shrink those parts any smaller.

In this particular case its quite appropriate that the bit rates are not maxed out because both the clients and the parents are of modest means and high end f*** o** players and computers maybe needed for high bit rates are not part of their world.

I don't really like the concept of two discs sets hence my post but each to their own. I already now supply an MP4 version at 1280x720 at a decent bit rate for playing on computers so the actual box already contains two discs; don't want to go to triple boxes. In this case the MP4 version is obviously very nice but the DVD version does compare well enough when alongside the MP4 on a Playstation 3 into a 50" Panny plasma and a 42" Sony LCD :- )

Pete