Chapter 6 Working with AVCHD 113
Frame Dimensions, Number of Lines, and Resolution
AVCHD supports three HD video resolutions:
Â1920 x 1080: This format is sometimes called Full HD because it contains the full 1920
horizontal pixels of the 1080-line HD format.
Â1440 x 1080: This is a horizontally subsampled image with 1080 lines.
Â1280 x 720: This is a full-resolution 720p format.
SD NTSC- and PAL-compatible formats are also defined in the AVCHD specification:
Â720 x 480 at 60i
Â720 x 576 at 50i
Important: The SD AVCHD formats are not supported by Final Cut Pro.
Frame Rate
The specified AVCHD frame rates are:
ÂNTSC-compatible frame rate: 29.97 fps (1080i60, 720p60)
ÂPAL-compatible frame rate: 25 fps (1080i50, 720p50)
ÂFilm-compatible frame rate: 23.98 fps (1080p24, 720p24)
Scanning Method
AVCHD can record either interlaced or progressive scan images:
Â1080 lines: Interlaced (1080i) or progressive (1080p)
Â720 lines: Progressive
Color Recording Method
The AVCHD color sample ratio is 4:2:0, with 8 bits per sample.
Data Rate
The amount of storage space required by AVCHD footage depends on the quality
setting chosen on the camcorder. Most camcorders support several quality levels,
although these quality levels have different names and bit rates on different
camcorders. When variable bit rate (VBR) encoding is used, complex and rapidly
changing video requires more data, shortening recording time. Therefore, stated
variable bit rates are an average.