A couple of weekends ago, I attended a horse show, mainly as a spectator and to get a feel for equestrian events. I brought my trusty XDCam EX with me and recorded about 2-1/2 hours of footage over the course of the morning and part of the afternoon.
I shot some footage in 720p 60 so that I could slow it down in post, at will, using time remapping and keyframing. This enables those neat shots where we slow the horse down just at the jump.
I learned a lot about Adobe Premiere and how it handles XDCam footage at this and another long-form event I recorded this past week: it gobbles up terabytes of temp disc space in just a month of working with XDCam footage where the shots span files and folders on disc.
Adobe has a bug which causes it to duplicate a clip that was reconstructed from spanned files. For instance, if a long shot spans six folders on disc, that shot will be assembled into a continuous shot from the six parts, in Premiere, but then the reconstituted shot will also be duplicated six times. This results in six times as many media cache files and conformed audio files as needed. That's where my terrabyte of free disc went last month.
The project was about shooting the event for 24p frame rate and achieving a nice theatrical look. I also wanted printable stills, so I used a 22.5º shutter.
My goal was to make a standard def DVD that looks great. That meant rendering only 23.976 fps into the MPEG2 file. However, since the DVD spec requires a 29.97 stream, I had to trick things to make it work. With the help of a utility called DGPulldown, I was able to alter the flags in the MPEG2 file so that it looked like a 29.97 frame rate, but also contained the right flags every 3:2 frames for inverse telecine in the DVD player.
The trick worked. I had burned two versions, one with pullup being done in the encoding, resulting in a 29.97 MPEG2 file, and this 23.976 file with tricked up flags. The difference that extra bandwidth per frame makes is nothing short of dramatic, with fast-moving footage under difficult conditions with lots of foliage in every shot. While the 29.97 MPEG looked good, on paused frames one could see macroblocks and mosquito noise in the fast action pan shots. Not so with the 23.976 footage. It made the difference between make or break.
I had also done some other things to add punch to the details on the SD picture. This involved added sharpening in the horizontal direction with just the right pixel radius to avoid ringing, yet clarify details. I did numerous test renders to establish optimal values. What a difference it makes over non-sharpened footage! I also deepened the black levels and increased the saturation, to make up for loss of these things caused by the compression process at render time.
The real test was to pit it against Hollywood's DVDs. So I went through my collection and chose one live-action movie and one CG movie. CG tends to be insanely-sharp, even on DVD, so I wanted to see how we do against an 'unfair' comparison. Looking at all three videos on a 47" screen at about 18" viewing distance, I was able to see things nobody ever notices. I saw plenty of mosquito noise on the two commercial DVDs. But worse than that, the commercial releases, even the CG movie, had grain and oversharpening artifacts (black halos) around edges. My DVD looked every bit as sharp, but lacked grain noise and halos. The overall look was significantly cleaner than the two Hollywood offerings.
Needless to say, I am very pleased with the results. The DVD looks more like 720p when watched from 7' away. The colors are punchy, the dynamic range is fantastic and there are details to a level you'd never expect on a DVD. Pause just about any frame and it's a printable still. The slo-mo shots look great. The highlights are not blown, yet there's plenty of detail in the shadows, thanks to careful knee settings I developed for the XDCam.
The benefits of 24p for DVD are quite compelling. So much so, that I spent some time trying to determine how to get 24p out of my two HDV cameras. That was not so possible, do to a lack of proper flags in the camera footage. There's a horrible cadence to fake '24p' footage from HDV that it begs the question "why bother?" So it may be that HDV is the only thing holding me back from producing all future DVD programming where I do multiple camera shoots in 24p. I have not found an acceptable pulldown solution for 24pA footage from HDV. And the nature of HDV may be the reason. It's more reason to dump the rest of our HDV tools and replace all with XDCam units.
