Video decoder

A video decoder is an electronic circuit, often contained within a single integrated circuit chip, that converts base-band analog video signals to digital components video. Video decoders commonly allow programmable control over video characteristics such as hue, contrast, and saturation. A video encoder performs the inverse function of a video decoder; it converts raw (uncompressed) digital video to analog video.

The input signal to a video decoder is analog video that conforms to a standard format such as NTSC or PAL. The output digital video may be formatted in various ways, such as 8-bit or 16-bit 4:2:2, 12-bit 4:1:1, or BT.656. Usually, in addition to the digital video outputs, a video decoder will also generate and output synchronization, blanking, field, lock, and clock signals.

Functional blocks

The main functional blocks of a video decoder typically include these:

• Analog processors
• Y/C (luminance/chrominance) separation
• Chrominance processor
• Luminance processor
• Clock/timing processor
• A/D converters for Y/C
• Output formatter
• Host communication interface