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AAC (Advanced Audio Coding) Also called MPEG-4 Audio. A standard way of compressing and
encoding digital audio. AAC-encoded les rival the quality of audio CDs and generally sound as
good as or better than MP3 les 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 le format developed by Apple.
Like WAV les, AIFF les 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.
Apple ProRes The Apple ProRes codecs provide an unparalleled combination of multistream,
real-time editing performance coupled with impressive image quality at reduced storage rates.
In particular, the Apple ProRes codecs have been designed to work especially well as high-
quality, high-performance editing codecs for Compressor, taking full advantage of multicore
processing and featuring fast, reduced-resolution decoding modes.
All members of the Apple ProRes codec family support any frame size (including SD, HD, 2K, and
4K) at full resolution. The data rate of Apple ProRes varies based on codec type, image content,
frame size, and frame rate.
Apple ProRes includes the following formats:
•
Apple ProRes 422: This codec oers nearly all the benets of Apple ProRes 422 (HQ), but at 66
percent of the data rate for even better multistream, real-time editing performance.
•
Apple ProRes 422 (HQ): This codec preserves visual quality at the same high level as Apple
ProRes 4444, but for 4:2:2 image sources. With widespread adoption across the video post-
production industry, Apple ProRes 422 (HQ) oers visually lossless preservation of the highest-
quality professional HD video that a single-link HD-SDI signal can carry. This codec supports
full-width, 4:2:2 video sources at 10-bit pixel depths, while remaining visually lossless through
many generations of decoding and re-encoding. The target data rate of Apple ProRes 422 (HQ)
is approximately 220 Mbps at 1920 x 1080 and 29.97 fps.
•
Apple ProRes 422 (Proxy): This codec is intended for use in oine workows that require low
data rates but full-resolution video. The target data rate is roughly 30 percent of the data rate
of Apple ProRes 422.
Glossary
67% resize factor