3 Flashcards
Explain the difference between analog and digital waveforms
Analog: Continuous and varying.
Digital: Binary
Sampling
The process of taking an accurate snapshot of an analog waveform at a particular time
Digitization
The process of converting a sample into a binary numeric value
What is a sampling rate and how is it typically measured?
The frequency in which snapshots or “samples” are taken. Measured in hertz (Hz).
The Nyquist-Shannon sampling theorem tells us that an analog signal can be accurately represented if it is digitally encoded using a sampling rate that is…
Twice greater than the highest frequency being sampled.
A traditional audio CD is sampled at how many kHz?
44.1kHz
Blu-ray recordings are typically sampled at how many kHz?
48kHz, 96kHz, or 192kHz
Bit Depth
The number of bits you have to describe a value.
Bit Rate
Measurement of the flow of information over time in a digital signal stream. Measured in bits per second (bps).
How do you calculate Bit Rate?
Sample rate x bit depth
Compression
Process that allows us to reduce the size of a data stream or file
ZIP, FLAC, MPEG-2, PNG, and JPEG2000 are examples of…
Lossless compression
MP3, JPEG, HEVC, and H.264 (aka AVC) are examples of
Lossy compression
Encoding
The process of analyzing data to reduce its size
Decoding
The process of returning compressed data to its original format.
A digital media file contains two elements:
Container: Structure of the file where data and metadata are stored
Codec: Provides method of encoding and decoding data
Bit
Binary digit. This is the smallest unit of digital information and may have the value 1 or 0.
In a digital signal, the on state is represented by ___, and the off state is represented by ___.
1 and 0
A signal that has many varying states is called a(n) ______ signal.
Analog
Lossy compression is particularly suitable for the transmission of:
A. Spreadsheets
B. Financial data
C. Text files
D. Audio, video, and images
D
What is a codec?
A device or processing system that encodes and decodes data.
Noise overcomes the signal after many generations of re-amplification of a(n) ______ signal.
Analog
