How do the studios do their DVD's

[Calvin Bellows]

I was just wondering how the studios can fit sooo much information onto 1 DVD and still have it look good. There is a 2-3 hour movie and all the bonus material. I shoot grads that take 4-5 hours and there is no way from what I have tried that I can get more then 2.5 hours on a DVD. Thoughts?

[Don Bloom]

First they use dual layer discs. They also don't burn they press. Different process, but the biggie is the dual layer.

[Peter Manojlovic]

Don't forget, they're encoded as 24FPS, therefore more bitrate gets allocated to less frames then 29.97FPS.
Since the source footage is usually film, it's way superior to what most people in the event world are using.
The gradients and overall tone leave breathing space for better encoding.

Yes, the authoring stations that ouput the DVD masters are running $20000 and up, the truth of the matter is, they're already ahead of the rest of us because of source footage alone.

The only way you could possibly get 4-5 hrs of footage, is to use Dual layered DVD's, and compress the heck out of the video stream.
Either that, of seriously start cutting some of that footage away...4-5 hours seems long..

[Calvin Bellows]

Yea it is long but there is 400 grads They all have to walk across the stage get their diploma. After that they have there grand march where grads hand out their awards, they do their talent show, show off their gowns etc. Can't cut any of that out. Right now I do 1 DVD for the Grad and 1 for the Grandmarch. Do you think it would be cost effective to do just 1 dual layer disk? Will most DVD players read that?

[Eric Olson]

Originally Posted by Calvin Bellows

I shoot grads that take 4-5 hours and there is no way from what I have tried that I can get more then 2.5 hours on a DVD.

Generally I would use two single layer disks in place of a dual layer disk. A bitrate of about 4 kbps will fit more than 4 hours on a dual layer DVD and more than 2 hours on a single layer disk. To obtain a high quality DVD at this bitrate try the following:

1080i60
->deinterlace->1080p60
->motion compensated noise filter
->skip print->1080p30
->anti-aliasing low pass filter
->lanczos resize->480p30
->mpeg2 encoder->DVD

The above workflow can be accomplished for free using AviSynth and HC Encoder or using specialized scaling hardware and the CinemaCraft mpeg2 encoder. Note that it is important to use progressive mpeg2 encoding with soft 2:2 pulldown in the final step. Note also that the scalers and encoders built into most NLEs do not achieve as good quality especially at low bitrates.

[Peter Manojlovic]

Great job Eric...

It's nice to see you take your downscaling seriously..I just wish Adobe took it just as seriously.

Ever since i've gone to +DL disks, i've never gone back...
Single disks are preferred, but when you're pushing beyond two hours, then +DL is the way to go..
As long as you author correctly, and use IMGBurn correctly, then there shouldn't be any problems..

[D.J. Ammons]

I have only used dual layer DVD's for one project because of the length of the final project but they worked well. Just expensive compared to regular blank DVD's!

[Garrett Low]

First if you analyze a studio disc you'll notice that they are running much lower data rates. They can do this because the encoding engines they use are very sophisticated and can do multi-pass encoading (not just 2 pass like up to 8 passes). Most of the system are dedicated so they can be specifically tweaked to do only encoding. These systems are massively expensive mostly due to the cost of the encoding engine. An example is Sony's current studio Bluray encoding engine has a price tag of $40,000 (yes there are that many zeros for just the software). CinemaCraft sells the encoding engine for the Xtream Encoader which is called Cinema Craft Encoder SP3 for $1000. I've only known one person who had this program and it has controls up the wazoo so you can customize the encoding settings for each scene. It takes a lot of time and knowledge to mess with some of the settings (such as changing the quantization matrix) but if you know what you're doing and you have a lot of time to let it process, the results will be studio quality looking mpg encoding with smaller files.

[Calvin Bellows]

Thank for the info eric what would you do with 720p60 footage? I am really trying to wrap my head around everything with burning to get the best quality I can. So much to know. I appreciate everything.

[Eric Olson]

Originally Posted by Calvin Bellows

what would you do with 720p60 footage?

It appears you have two types of footage: the graduate ceremony and the talent show.

Assuming the graduate ceremony doesn't have any fast paced sports action in it, then skip printing 60p to 30p and scaling to SD should work well. If the talent show has any fast paced action or dancing then this may require a different approach. My guess is that most of the talent show is singing, fashion and acting which should still look fine at 30p. Isolate the fast moving dance scenes into separate clips and weave the 60p source to interlaced SD at a higher bitrate for those scenes.

The result is a bunch of 480p30 mpeg2 clips flagged for 2:2 pull down and a few true 480i60 mpeg2 clips. Now master these files to a DVD without reencoding. The open source program dvdauthor

dvdauthor

can do this as well as many other DVD authoring tools.

[Ervin Farkas]

Originally Posted by Eric Olson

1080i60 -> deinterlace->1080p60

How does deinterlacing produce 60P from 60i???

[Eric Olson]

Duplicate post...see below:

[Eric Olson]

Originally Posted by Ervin Farkas

How does deinterlacing produce 60P from 60i???

Unless you skip half the fields you always get 60p. Since 60p is not DVD compliant, lots of software and hardware skip half the fields by default to directly make 30p. The reason I first deinterlaced to 60p was so the noise filters had more data to work with.

[Ervin Farkas]

60i means 60 HALF frames; when combined through the process called deinterlacing, the two half fields produce ONE FRAME.

60/2=30 - 60i deinterlaced produces 30P.

[Eric Olson]

Originally Posted by Ervin Farkas

60i means 60 HALF frames

Right, in other words, 60i means 60 fields per second. Throw away half the fields and you have 60/2=30p. Keep all the fields by converting them to frames and you have 60p.