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Table Of Contents
DVCPRO HD
A high-definition video format used to capture video digitally from FireWire-enabled
DVCPRO HD compatible decks. (Not to be confused 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. DVCPRO HD uses 4:2:2 color sampling for high color fidelity, and has a fixed
data rate of 12.5 MB/sec.
Note: DVCPRO HD movies do not support alpha channels.
DVCPRO 50
A standard-definition codec used to capture video digitally from FireWire-enabled
DVCPRO 50-compatible camcorders and decks. Although it’s similar to the DV codec
because DVCPRO 50 is imported as YUV encoded video, it produces considerably higher
quality video because it uses less compression. (DVCPRO 50 uses a 3:3:1 compression
ratio, versus DVs 5:1 compression ratio.) DVCPRO 50 also uses 4:2:2 color sampling for
high color fidelity, as opposed to DVs 4:1:1 color sample rate. DVCPRO 50 has a fixed data
rate of 7 MB/sec.
Note: DVCPRO 50 movies do not support alpha channels.
Third-Party Codecs
Numerous video-editing solutions use different codecs, some of which may be available
for installation to encourage interoperability. For more information, contact the
manufacturer of the editing system.
Note: Most third-party codecs cannot have alpha channels.
Field Order
When a video display is fed an interlaced video signal, each frame of video is split into
two fields, each of which contains a set of alternating lines of horizontal resolution running
across the screen. Standard-definition NTSC and PAL are both interlaced video formats,
while some high-definition video formats, and all video displayed on a computer screen,
are progressive-scanned video formats. With progressive scanning, these lines are drawn
one at a time, from the top of the screen to the bottom.
When you record interlaced footage with a camcorder, each video frame is split into two
fields, each containing half of the total lines of resolution in the frame. The first field is
recorded, then the second, one after the other, so both fields constitute one frame. When
you play the video back, the monitor displays each recorded frame in succession, first
drawing one field, then the other.
1425Appendix B Video and File Formats