Apple Motion 2 - Manual (Page 949)

Appendix B Video and File Formats 949
Video footage, which generally has more grain, noise, and variations of texture and
color than animated material, may not be compressed as much with the Animation
codec as with other methods. Because some lossless compression is better than none,
this codec is used more frequently than Uncompressed.
DVCPRO 100
A high definition video format that can be used to capture video digitally from
FireWire-enabled DVCPRO100 compatible decks. Don’t confuse this format with
DVCPRO 25 or DVCPRO 50, which are both standard definition formats. This format
supports a number of frame sizes and frame rates, including a 24p format that offers
variable speed via a variable frame rate technology. DVCPRO50 uses 4:2:2 color
sampling for high color fidelity, and has a fixed data rate of 12.5 MB/sec.
DVCPRO50
The DVCPRO50 codec is used to capture video digitally from FireWire-enabled
DVCPRO50-compatible camcorders and decks. Although it’s similar to the DV codec in
that DVCPRO50 is imported as YUV encoded video, it produces considerably higher
quality video since it uses less compression. (DVCPRO50 uses a 3.3:1 compression ratio,
versus DV’s 5:1 compression ratio.) DVCPRO50 also uses 4:2:2 color sampling for high
color fidelity, as opposed to DV’s 4:1:1 color sample rate. DVCPRO50 has a fixed data
rate of 7 MB/sec.
Apple M-JPEG
There are two Apple M-JPEG codecs, M-JPEG A and M-JPEG B. These are variable data
rate codecs similar to the ones used by video capture cards. If you need to deliver more
heavily compressed material to keep files small, consider these codecs. M-JPEG is a
lossy codec and results in artifacts in your final video. The severity of these artifacts
depends on the data rate you choose.
Several capture and playback cards on the market can play back either M-JPEG A or M-
JPEG B in real time without rerendering the material, or at most, doing minimal
rerendering. This makes file interchange very fast. Before you use either M-JPEG A or B,
consult the manufacturer of the capture card you’re using to find out which one you
should use.
Note: Apple M-JPEG movies cannot have alpha channels.
JPEG
JPEG is similar to M-JPEG, except that the compression artifacts can be less severe at
similar data rates. JPEG movies may play back in real time on your system, depending
on your system’s speed and the data rate of the movie.
Note: JPEG movies cannot have alpha channels.
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