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Chapter 42 Audio Fundamentals 591
VIII
When the number of bits per sample is increased, each sample can more accurately
represent the audio signal.
These analog-to-digital rounding errors are known as quantization errors . Each time a
digital signal is processed, it is subject to rounding, which can compound errors over
time. To avoid rounding errors, you should always use the highest bit depth your
equipment supports. Most digital video devices use 16- or 20-bit audio, so you may be
limited to one of these bit depths. However, professional audio recording devices
usually support 24-bit audio, which is quickly becoming the industry standard.
2 bit1 bit
16 bit4 bit
Bit depth When used
32-bit floating point Internal resolution of the Final Cut Express HD audio mixer. This
allows audio calculations, such as fader levels and effects
processing, to be performed at very high resolution with a
minimum of error, which preserves the quality of your digital audio.
24-bit This is becoming the audio industry standard for most audio
recording formats. Most professional audio interfaces and
computer audio editing systems can record with 24-bit precision.
16-bit DAT recorders, Tascam DA-88 and ADAT multitracks, and audio CDs
all use16-bit samples. Many digital video formats, such as DV, use
16-bit audio.
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8-bit In the past, 8-bit audio was often used for CD-ROM and web video.
Today, 16-bit audio is usually preferred, but available bandwidth
and compatibility with your target user’s system are your chief
considerations when outputting audio for multimedia use.
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Many consumer DV camcorders allow you to record 4 audio channels using 12-bit mode, but this is
not recommended for professional work.