Abstract: A method of generating an output video signal includes processing two or more input digital video signals so as to manipulate images that they represent and combining the processed signals to form the output video signal, which represents a composite image in which the manipulated images appear to fly through one another. In a first pass, a digital video effect generator (1) is supplied (4) with one of input video signals and is responsive to data (5) representing at least the manipulation to which the image represented by that one input signal is to be subjected to process that one input signal to subject the image represented thereby to the manipulation intended for that image. The processed signal resulting from the first pass is recorded (VTR1).

Abstract: In a method of converting a 60 field/s 2:1 interlaced video signal to 24 frame/s film, for each sequence of five input fields: the fields of at least one pair of the input fields are each progressive scan converted to form a pair of frames, and a weighted addition of the frames is made on a pixel-by-pixel basis to form an output video frame with a shifted temporal centroid, so that the temporal centroids of the output video frames are equally spaced. The output video frames are then recorded on film. In another method, the progressive scan conversion and weighted addition is performed by a single filter.

Abstract: A digital video signal is real-time converted from a high definition format, such as 1125 lines, 60 field/s, 2:1 interlace, with a 16:9 aspect ratio and 1920.times.1035 active pixels to a conventional definition format, such as 525 lines, 60 field/s, 2:1 interlace, with a 4:3 aspect ratio and 720.times.486 active pixels.The image is compressed so that the active area extends across only part of an intermediate field/frame.The pixels are written of the high definition fields to alternate field stores at the high definition format pixel rate.The output frames are formed in the conventional definition format by reading, at the conventional definition pixel rate, pixels of at least part of the active portion from the field store which is not being written.

Abstract: Video tape recorder speed control apparatus for controlling a video tape recorder (1) to cause it to reproduce a recorded video signal at a predetermined speed, such as a fraction 1/n of the normal speed, the apparatus comprising the video tape recorder (1), first and second counters (25,26), the first and second counters (25, 26) being incremented by a signal locked in frequency to the field repetition frequency of the video signal at the normal playback speed thereof, the first counter (25) resetting periodically at intervals determined by the predetermined speed, the second counter (26) being reset with a signal locked in frequency to the field repetition frequency of the video signal being reproduced by the video tape recorder (1), a comparator (27) for periodically comparing the counts of the first and second counters (25, 26) thereby to derive a phase error signal, and a control signal generator (28, 29, 30) to derive in dependence on the phase error signal a signal to control the reproduction speed of

Abstract: A data decoder is described for decoding interleaved first type code words [RUNLENGTH, SIZE] and second type code words [AMPLITUDE], each first type code word serving to define a runlength of constant values preceding a variable value defined by a following second type code word. The first type code words and the second type code words are fed to respective first and second pipeline delay units 22 and 24. The output from the first pipeline delay unit 22 is fed to a state machine 26 which reads the RUNLENGTH value and generates an INSERT ZEROS signal for a period proportional to the RUNLENGTH value followed by a signal triggering reading of the second pipeline delay unit 24. The INSERT ZEROS signal and the output of the second pipeline delay unit 24 are fed to a multiplexer 28 which selects between them to generate the appropriate OUTPUT signal. A swing buffer 10 is disposed upstream of the first and second pipeline delay units 22 and 24.

Abstract: A data compression system in which decorrelated data is fed to an entropy encoder (20) in batches having an internal monotonic decrease in average information content from start to end. This results in longer zero runs and more rapid attainment of end of block codes. A data sequencing circuit (18) comprising nested inter-sub band (60) and intra-sub band (72) counters for use with sub band filtered video data is also described.