Apple Compressor (4.1.2) - Manual (Page 104)

104
AAC (Advanced Audio Coding) Also called MPEG-4 Audio. A standard way of compressing and
encoding digital audio. AAC-encoded files rival the quality of audio CDs and generally sound as
good as or better than MP3 files encoded at the same or even a higher bit rate.
AC-3 (Audio Codec 3, Advanced Codec 3, Acoustic Coder 3) A Dolby Digital compressed audio
format often used for encoding surround sound.
AIFF (Audio Interchange File Format) A cross-platform audio file format developed by Apple.
Like WAV files, AIFF files contain “chunks” of information such as the Sound Data Chunk, which
contains the actual sample data, and the Common Chunk, which contains sample rate and bit
depth information.
Anamorphic Some video camcorders and recording devices shoot at a widescreen 16:9 aspect
ratio but record the data using a 4:3 aspect ratio. Sometimes the metadata specifying 16:9
playback in the video file is missing or set incorrectly. In Compressor, you can manually adjust
the aspect ratio so that video plays correctly with a widescreen 16:9 aspect ratio. (Note that this
option applies only to standard-definition formats.)
Apple ProRes Apple ProRes codecs provide an unparalleled combination of multistream, real-
time editing performance, impressive image quality, and reduced storage rates. Apple ProRes
codecs take full advantage of multicore processing and feature fast, reduced-resolution decoding
modes. All Apple ProRes codecs support any frame size (including SD, HD, 2K, and 4K) at full
resolution. The data rates vary based on codec type, image content, frame size, and frame rate.
Apple ProRes includes the following formats:
•
Apple ProRes 4444 XQ: The highest-quality version of Apple ProRes for 4:4:4:4 image
sources (including alpha channels), with a very high data rate to preserve the detail in
high-dynamic-range imagery generated by today’s highest-quality digital image sensors.
Apple ProRes 4444 XQ preserves dynamic ranges several times greater than the dynamic
range of Rec 709 imagery—even against the rigors of extreme visual effects processing,
in which tone-scale blacks or highlights are stretched significantly. Like standard
Apple ProRes 4444, this codec supports up to 12 bits per image channel and up to 16 bits for
the alpha channel. Apple ProRes 4444 XQ features a target data rate of approximately 500
Mbps for 4:4:4 sources at 1920 x 1080 and 29.97 fps.
•
Apple ProRes 4444: An extremely high-quality version of Apple ProRes for 4:4:4:4 image sources
(including alpha channels). This codec features full-resolution, mastering-quality 4:4:4:4 RGBA
color and visual fidelity that is perceptually indistinguishable from the original material.
Apple ProRes 4444 is a high-quality solution for storing and exchanging motion graphics
and composites, with excellent multigeneration performance and a mathematically lossless
alpha channel up to 16 bits. This codec features a remarkably low data rate compared to
uncompressed 4:4:4 HD, with a target data rate of approximately 330 Mbps for 4:4:4 sources
at 1920 x 1080 and 29.97 fps. It also offers direct encoding of, and decoding to, both RGB and
Y'C
B
C
R
pixel formats.
Glossary
67% resize factor