Sunday 26 November 2006

Hindi movie DVD authoring

I've just finished authoring the DVD for a movie called 'Don' starring Shahrukh Khan, Priyanka Chopra, Isha Koppikar and Directed by Farhan Akhtar. The DVD is set to be released in the US in the first week of Dec, and a bit later in other parts of the world. An Indian version will release some weeks from now.

I used Apple DVD Studio Pro for the entire job and Final Cut Pro for the slight editing, sound syncing and other video processes. Its not all finished yet, but there were quite some learnings from this.

For one thing, Hindi movies are usually 170-190 mins in duration. Compared to most English movies which are between 90 and 130 mins. So the compression used is much greater. And the picture gets coarser. Further most post houses do a telecine to video for the DVD. This sometimes adds a small shake in the picture and that too adds to the quality hit since the compressor has to work harder.

And NTSC. For some reason all Hindi films have to be released in NTSC. So the PAL - NTSC or 24fps - NTSC conversion adds a further hit to the picture quality with the added interpolated frames.

For Don I made the DVD for from the original digital files that were created after DI and used to write to film for the final negative. So I had none of these problems. And the resulting picture looks definitely cleaner and sharper - no dirt, scratches and hair. And the colours are exactly what the Cinematographer and colourist set while grading the film.

The process is much slower however. Telecine could have been done in about half a day while this conversion can take many days of rendering. But the sheer quality gain makes it worth while. I believe Don is the first Hindi movie DVD to be made this way.

On DVDs. The structure of a DVD is governed by a DVD specification laid down many years ago. A lot of the visual effects that we're used to seeing on TV are simply not permissible on a DVD. Soft shadows, fast moving intros, transitions all are complex images that tend to break up into compression 'blockies' unless one is really careful.

A 'normal' DVD also called DVD-9 can hold about 8.5 Gb. This amounts to about 8200 Mb numerically. The data is spread over two layers both on the same side. So layer 0 is the bottom layer written from the inside to the outside. When the laser reaches the outermost edge it switched layers and starts reading inwards. This layer switch has to be at the same place on the DVD. Which means that layer 0 cannor be smaller than layer 1.

And there is a small pause between layers which depends on your player's ability to switch focus. Naturally the best point to place this break is at the interval. But for that the first half has to be longer than the second half. If your movie has a longer second half you have to make a break somewhere after the interval.

Add to this the fact that the company that markets the DVD add so many ads, trailers and promos that its not unusual to have to sit through 5-8 mins of promotionals before one gets to see the movie. And none of this can be 'fast-forwarded'. This could get very irritating. In Don, I've made most of this stuff skippable.

Finally, colours. As most users will see the DVD on just about any TV set - from a 5 year old CRT to a new large plasma - its really had to make a picture that will look universally good. Especially in India where the average home has a rather poorly adjusted TV set.

This is not the same challenge as telecast, Because in telecast at least the system sending out the signal is common and of good quality. Whereas in DVD, the source - a DVD player - is individual and different in every home. So its impossible to preview a DVD as it would appear in 'the average home'. For Don, I set my judgement to an 'average' DVD player, and a 'standard' broadcast monitor. And did a second check at home on a rather well calibrated 5 year old TV set.

But overall, this is not a very heartening experience. Add to this the fact that the authoring and QC process can take almost a week to 10 days and is not billed for as an additional service makes this a not very encouraging job. But some day I hope to be able to use these learnings in making DVD authoring a moe valued job function.