Apparatus for recording and reproducing digital signals stored on magnetic tape

An apparatus for reproducing image signals, which are digitally stored on a magnetic tape, in an efficient manner, comprising:

• code arranging means for adding a flag to a data signal so as to produce a coded data signal, wherein:
• said data signal includes intra-frame coded data and inter-frame coded data that has been time divisionally multiplexed together,
• said flag identifies at least one portion of said data signal that is comprised of intra-frame coded data, and
• said intra-frame coded data and inter-frame coded data are based upon said image signals;
• recording means for recording said coded data signal onto said magnetic tape;
• reproducing means for reading said magnetic tape and reproducing said coded data signal, which is stored thereon, wherein:
• a speed at which said reproducing means operates can be varied from a normal operating speed to a higher operating speed,
• said magnetic tape is moved more quickly with respect to a head of said reproducing means when said reproducing means operates at said higher operating speed as compared to when said reproducing means operates at said normal operating speed, thereby causing said head to traverse tracks on said magnetic tape more quickly when said reproducing means operates at said higher operating speed as compared to when said reproducing means operates at said normal operating speed, and
• said higher operating speed is equivalent to said normal operating speed multiplied by a speed multiplying coefficient;
• flag detecting means for detecting said flag within said coded data signal that has been reproduced by said reproducing means;
• decoding means for decoding said coded data signal that has been reproduced by said reproducing means by intra-frame decoding processing or inter-frame decoding processing, thereby producing a reproduced data signal;
• recording position presuming means for presuming, when said reproducing means operates at said higher operating speed and based on said detection made by said flag detecting means, a position where said intra-frame coded data is recorded on said magnetic tape, said presumed position indicating one of said tracks on said magnetic tape;
• reproducing control means for controlling said speed at which said reproducing means operates, said reproducing control means operating based on said presumed intra-frame coded data position and said speed multiplying coefficient, said reproducing control means allowing for said intra-frame coded data to be decoded by reproducing said intra-frame data at a normal speed;
• and
• means for outputting, at a cycle that is based on said speed multiplying coefficient, a decoded signal, which is based on said reproduced data signal.