# Preparing source material

Video capture and compression are time-consuming, so prepare source material carefully. Typical source materials include:

- your own video
- film- or video-based material from video tape or laser disc
- computer animations

Keep in mind that storage becomes an issue as soon as you get into the digital world. Each second of video takes about 5 minutes of processing time and requires 30 MB when digitized. Don't expect to capture first and edit later; instead, edit your beta tapes as far as possible before compressing them. Try to digitize only the material you need-but use the highest quality possible.

## Securing a master copy

Make a copy of your source material to use as a "working master," and for dubbing working copies. Store the original in a safe place. Remember that during capture each segment of the video is played multiple times, which can result in degradation of the quality.

## Shooting your own video

Plan your shoot or select your video carefully. Advice on producing materials that compress well is provided in the section "Will It Compress Well?" later in the chapter. The following tips apply to shooting your own video:

- Determine the final frame rate before shooting so you can shoot at a lower frame rate, thus decreasing the disk space you'll need.

- Reuse a single segment, if possible. For example, tile 10-second pieces of moving water for longer stretches.

- Use high-quality equipment, such as Betacam SP.

- Be prepared to deal with interlace effects in moving from analog (double-buffered) to digital video. You can deinterlace using linear interpolation with edge following, as discussed below.

## Preparing film source material

Many videos started out as film; using video derived from film requires special consideration, because the Telecine process inserts composite frames into the video. Also, eliminate as much noise as possible to minimize problems during compression.

### Understanding the Telecine process

When producing video from film source material, studios use the Telecine process to transfer the source material from celluloid to magnetic tape, and from 24 fps to 30 fps. Telecine conversion is explained in detail in Chapter 5, "Video Tools," in the section "The 3-2 Pulldown tool."

## Will it compress well?

When preparing source material, keep in mind certain factors that can affect how well or how badly the material compresses.

### Eliminating noise

Most films have noticeable film grain noise and scratches. To the compression tool this noise is significant, and is maintained or even emphasized during compression. Therefore, you should remove as much of it as possible before compression. Below are several options for reducing film grain noise:

- A post-production studio can clean up analog film.

- If your source is film, reduce grain noise using a median or recursive noise filter, which picks out sharp anomalies like spots or pops.

- On D1, D2, or D3 video, a digital filter can be used right after the Telecine process.

- Low-light shoots generate more film or video noise. Three CCD (couple-charged device) cameras generate less video noise.

### Edge crawl

Jagged edges cause edge crawl on TV monitors. Edge crawl can be caused by uneven resizing or aliasing, so always use anti-aliasing resizing.

### Other considerations

Bear in mind that:

- A source with constant backgrounds and solid colors yields the best results.
- Slow color gradients cause color banding when compressed with Cinepak.
- Slow pans/zooms are difficult to compress well.