Intermediate picture field storage system for variable speed magnetic tape video data read-out

Video data intermediate storage system for variable speed equipment for reading out from a magnetic tape video data recorded with sector subdivisions in a plurality of channels, having tape speed control means providing settings for tape speeds respectively slower than, equal to, or greater than the tape speed at which video data was recored on the tape, comprising:

• four picture field memories, each including a luminance sample value memory a chrominance sample value memory, a write flag memory and an error flag memory, said write flag memory being for storage of write flag for designating that, at a corresponding address, there is at least a luminance or a chrominance sample value which was not read-out in a previous picture field read-out;
• a set of four read/write switching means respectively connected to said picture field memories for connecting each of them selectively either exclusively for video data write-in or exclusively for video data read-out, in accordance with control signals for said respective memories;
• means for generating said control signals for said memories in such a way that at any one time only one of said picture field memories is available for readout and so that the number and sequence of said memories made available for write-in is variable, in repsonse to said settings of said tape speed control means, and for allocating the number of said picture field memories available for write-in in response to a said setting of said tape speed control means;
• write-in and read-out memory addressing means for addressing in every addressing step a luminance sample value a chrominance sample value, a corresponding error flag address, and a corresponding error flag address, and
• means for synchronizing switchover of said switching means and for synchronizing read-out from that one of said picture field memories which is being used in read-out therefrom, said synchronizing means including means for generating a reference synchronizing signal containing at least pulses of a read-out vertical scan frequency.