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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 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 output bus, a video decoder will also generate a clock signal and other signals such as: * Sync — indicates the beginning of a video frame * Blanking — indicates video blanking interval * Field — indicates whether the current video field is even or odd * Lock — indicates the decoder has detected and is locked (synchronized) to a valid analog input video signal ==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 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Video decoder」の詳細全文を読む スポンサード リンク
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