Wikify: date=March 2009 An encoder is a device, circuit, transducer, software program, algorithm or person that converts information from one format, or code to another, for the purposes of standardization, speed, secrecy, security, or saving space by shrinking size.

Examples

Software for encoding audio, video, text into standardized formats:

• A compressor encodes data (e.g., audio/video/images) into a smaller form.
• Windows Media Encoder captures, compresses, converts and can protect audio/video
• Riva FLV encoder converts AVI, DV, MPEG, MOV and WMV files to flash video files (*.FLV)
• An email encoder secures online email addresses from email harvesters
• A PHTML encoder preserves script code logic in a secure format that is transparent to visitors on a web site
• A text encoder converts text for use in a browser or web page
• A multiplexer combines multiple inputs into one output.

Job positions:

• A Data Entry Encoder may enter payment amounts from legal tender documents from financial institutions into a database.
• A Data Entry Encoder may enter data from phone surveys in a coded format into a database.
• A Manual Encoder may manually scan code tags on baggage that were missed by an automated system.

Security:

• A device or person that encodes military messages, such as the ADFGVX Cipher in WWI or the Enigma device in WWII.
• A Microchip hopping encoder integrated circuit for non-fixed-code secured entry.

Medical encoding software:

• EncoderPro searches ICD-9-CM, CPT and HCPCS Level II medical codes, to increase accuracy and allow ease of auditing for compliance

Transducers for encoding position or orientation:

• A rotary encoder converts rotary position to an analog (e.g., analog quadrature) or digital (e.g., digital quadrature, 32-bit parallel, or USB) electronic signal.
• A linear encoder similarly converts linear position to an electronic signal.

Encoder circuits are described below:

Encoder Circuit

An encoder can be a device used to change a signal (such as a bitstream) or data into a code. The code serves any of a number of purposes such as compressing information for transmission or storage, encrypting or adding redundancies to the input code, or translating from one code to another. This is usually done by means of a programmed algorithm, especially if any part is digital, while most analog encoding is done with analog circuitry.

Single bit 4 to 2 Encoder

An encoder has 2ⁿ input lines and n output lines.The output lines generate a binary code corresponding to the input value. For example a single bit 4 to 2 encoder takes in 4 bits and outputs 2 bits. It is assumed that there are only 4 types of input signals these are : 0001, 0010, 0100, 1000.

The encoder has the limitation that only one input can be active at any given time. If two inputs are simultaneously active, the output produces an undefined combination. To prevent this we make use of the priority encoder.