FULL MOTION VIDEO
Most modem cameras use a CCD for capturing the image. HDTV video cameras will be all-digital, and the capture method will be significantly different based on the new NTSC HDTV Standard.
Full-Motion Video Controller Requirements
Video Capture Board Architecture: A full-motion video capture board is a circuit card in the computer that consists of the following components:
(i) Video input to accept video input signals.
(ii) S- Video input to accept RS 170 input.
(iii) Video compression-decompression processor to handle different video compression-decompression algorithms for video data.
(iv) Audio compression-decompression processor to compress and decompress audio data.
(v) Analog to digital converter.
(vi) Digital to analog converter.
(vii)Audio input for stereo audio LINE IN, CD IN. (viii) Microphone.
A video capture board can handle a variety of different audio and video input signals and convert them from analog to digital or digital to analog.
Video Channel Multiplexer: It is similar to the video grabber's video channel multiplexer.
Video Compression and Decompression: A video compression and decompression processor is used to compress and decompress video data.
The video compression and decompression processor contains multiple stages for compression and decompression. The stages include forward discrete cosine transformation and inverse discrete cosine transformation, quantization and inverse quantization, ZigZag and Zero run-length encoding and decoding, and motion estimation and compensation.
Audio Compression: MPEG-2 uses adaptive pulse code modulation (ADPCM) to sample the audio signal. The method takes a difference between the actual sample value and predicted sample value. The difference is then encoded by a 4-bit value or 8-bit value depending upon the sample rate
Analog to Digital Converter: The ADC takes inputs from the video switch and converts the amplitude of a sampled analog signal to either an 8-bit or 16-bit digital value.
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