Video decoder

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A video decoder is an electronic circuit, often contained within a single integrated circuit chip, that converts base-band analog video signals (e.g., NTSC, PAL) to digital components video. Video decoders commonly allow programmable control over video characteristics such as hue, contrast, and saturation. In contrast, 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 8-bit ITU-R 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[edit]

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