Apparatus for a high definition VCR which selects a video signal characteristic to be transmitted depending on characteristics of the tap and channel

A signal characteristic variation apparatus for a high definition video cassette recorder, comprising:

• scaling means for selecting an output signal from an encoder or output data from a decoder in a television receiver under control of a first switch and formatting the selected signal or data into a data stream;
• variable length coding means for coding the output signal from said encoder or motion data, control data and DCT coefficient data output from said decoder at a variable length and outputting the coded data to said scaling means;
• scale control means for outputting a scale control signal to said scaling means according to a selected one of recording modes;
• error correction coding means for adding an error correction code to an output signal from said scaling means;
• formatting means for formatting an output signal from said error correction coding means in a recording format on a tape;
• channel modulation means for modulating an output signal from said formatting means at a frequency band suitable to tape and channel characteristics;
• test signal generation means for generating a test signal in response to a switching control signal which is generated according to the selected recording mode and passing the generated test signal at a predetermined frequency band, the test signal from said test signal generation means being used to discriminate the tape and channel characteristics;
• recording amplification means for amplifying an output signal from said channel modulation means or the test signal from said test signal generation means by a predetermined level under control of a second switch;
• first and second heads for recording an output signal from said recording amplification means on the tape;
• third and fourth heads for playing back a video signal or the test signal recorded on the tape in a playback mode;
• playback amplification means for amplifying the video signal or the test signal played back by said third and fourth heads by a predetermined level;
• tape characteristic detection means for receiving an output signal from said playback amplification means under control of a third switch and discriminating the tape and channel characteristics in response to the received signal;
• equalization means for compensating for distortion of the output signal from said playback amplification means in response to a first output signal from said tape characteristic detection means;
• channel demodulation means for demodulating an output signal from said equalization means at a frequency band suitable to the tape and channel characteristics in response to a second output signal from said tape characteristic detection means;
• deformatting and error correction decoding means for deformatting an output signal from said channel demodulation means into the original state and correcting an error of the resultant data stream;
• and
• inverse scaling means for performing inverse scaling of an output signal from said deformatting and error correction decoding means to extract motion data, the DCT coefficient data and the control data therefrom and outputting the extracted data to said decoder in said television receiver.