Video signal format for post-production

Abstract

Especially for use in post-production, a “gateway” format of video signal represents material which is acquired or generated at a real-time rate, but which is in a 60 field/s format at 1.25 or 1.2 times the real-time rate. The gateway video signal provides a number of advantageous possibilities, including: frame-locked transfer of material from real-time 24 frame/s and 25 frame/s film to the gateway format; frame-accurate post-production editing not requiring a 3232 relationship and retaining the gateway format; real-time post-production editing with a synchronized 3232 relationship between different sources and the product; and frame-locked transfer of material from the gateway format to real-time 24 frame/s or 25 frame/s film and 50 field/s video.

I claim  
     
         1 . A video signal representing material which is acquired or generated at a real-time rate, wherein the video signal is in a 60 field/s format at 1.25 or 1.2 times the real-time rate.  
     
     
         2 . A signal as claimed in    claim 1   , which is a 1125 lines/frame high definition video signal.  
     
     
         3 . A signal as claimed in    claim 1   , which is at 1.25 times the real-time rate.  
     
     
         4 . A signal as claimed in    claim 1   , which is at 1.2 times the real-time rate.  
     
     
         5 . The use of a 30 frame/s telecine to produce a signal as claimed in    claim 3    from 24 frame/s film.  
     
     
         6 . The use of a 30 frame/s telecine to produce a signal as claimed in    claim 4    from 25 frame/s film.  
     
     
         7 . A method of converting a source 60 field/s video signal to a signal as claimed in    claim 3   , comprising the step of dropping every fifth field from the source signal.  
     
     
         8 . A method of converting a source 60 field/s video signal to a signal as claimed in    claim 4   , comprising the step of dropping every sixth field from the source signal.  
     
     
         9 . An apparatus for reproducing a signal as claimed in    claim 3    from a source 60 field/s video signal recording, the apparatus including means for reproducing and outputting four out of every five fields of the recorded video signal.  
     
     
         10 . An apparatus for reproducing a signal as claimed in    claim 4    from a source 60 field/s video signal recording, the apparatus including means for reproducing and outputting five out of every six fields of the recorded video signal.  
     
     
         11 . An apparatus as claimed in    claim 9   , wherein said reproducing and outputting means comprises means for reproducing the recording at 75 field/s, and means for outputting four out of every five of the reproduced fields at 60 field/s.  
     
     
         12 . An apparatus as claimed in    claim 10   , wherein said reproducing and outputting means comprises means for reproducing the recording at 72 field/s, and means for outputting five out of every six of the reproduced fields at 60 field/s.  
     
     
         13 . The use of a 30 frame/s electron beam recorder to produce a film from a signal as claimed    claim 1   .  
     
     
         14 . A method of converting a first signal as claimed in    claim 1    to a second 60 field/s video signal, comprising the step of duplicating every fourth field of the first signal to produce the second signal.  
     
     
         15 . A method as claimed in    claim 14   , further comprising the step of keeping track of the duplicated fields.  
     
     
         16 . An apparatus for reproducing a 60 field/s video signal from a recording of a signal as claimed in    claim 1   , the apparatus including means for reproducing the fields of the recorded video signal and duplicating every fourth reproduced field.  
     
     
         17 . An apparatus as claimed in    claim 16   , wherein the reproducing and duplicating means comprises means for reproducing the recorded signal at 48 field/s and means for duplicating every fourth field to provide a field rate of 60 field/s.  
     
     
         18 . An apparatus as claimed in    claim 17   , further comprising means for keeping track of the duplicated fields.  
     
     
         19 . A method of converting a first signal as claimed in    claim 1    to a second 60 field/s video signal, comprising the step of duplicating every fifth field of the first signal to produce the second signal.  
     
     
         20 . A method as claimed in    claim 19   , further comprising the step of keeping track of the duplicated fields.  
     
     
         21 . An apparatus for reproducing a 60 field/s video signal from a recording of a signal as claimed in    claim 1   , the apparatus including means for reproducing the fields of the recorded video signal and duplicating every fifth reproduced field.  
     
     
         22 . An apparatus as claimed in    claim 21   , wherein the reproducing and duplicating means comprises means for reproducing the recorded signal at 50 field/s and means for duplicating every fifth field to provide a field rate of 60 field/s.  
     
     
         23 . An apparatus as claimed in    claim 22   , further comprising means for keeping track of the duplicated fields.  
     
     
         24 . A method as claimed in    claim 19   , further comprising the step of conversion from the second signal to a 50 field/s video signal by dropping one in every six fields of the second signal.  
     
     
         25 . A method as claimed in    claim 20   , further comprising the step of conversion from the second signal to a 50 field/s video signal by dropping one in every six fields of the second signal, wherein the dropped fields are the fields which were duplicated when producing the second signal from the first signal.  
     
     
         26 . An apparatus as claimed in    claim 21   , further comprising means for dropping one in every six fields of the 60 field/s signal.  
     
     
         27 . An apparatus as claimed in    claim 26   , wherein the field dropping means is provided by a 1125 lines, 60 field/s to 1250 lines, 50 field/s standards converter, or a 1125 lines, 60 field/s to 625 lines, 50 field/s standards converter.  
     
     
         28 . An apparatus as claimed in    claim 26   , further comprising means for keeping track of the duplicated fields, wherein the field dropping means is responsive to the duplicated field tracking means to drop to the duplicated fields.  
     
     
         29 . A method of post-production of one or more signals as claimed in    claim 1   , wherein post-production editing is carried out directly on the signals, but wherein, for previewing, the edited signal is converted to a second 60 field/s video signal by a method comprising the step of duplicating every fourth field of the edited signal to produce the second signal.  
     
     
         30 . A method of post-production of one or more signals as claimed in    claim 1   , wherein post-production editing is carried out directly on the signals, but wherein, for previewing, the edited signal is converted to a second 60 field/s video signal by a method comprising the step of duplicating every fifth field of the edited signal to produce the second signal.  
     
     
         31 . A method of post-production of one or more signals as claimed in    claim 1   , wherein post-production editing is carried out directly on the signals, but wherein, for previewing, the edited signal is converted by an apparatus for reproducing a 60 field/s video signal from a recording of the edited signal, which apparatus includes means for reproducing the fields of the recorded video signal by duplicating every fourth reproduced field.  
     
     
         32 . A method of post-production of one or more signals as claimed in    claim 1   , wherein post-production editing is carried out directly on the signals, but wherein, for previewing, the edited signal is converted by an apparatus for reproducing a 60 field/s video signal from a recording of the edited signal, which apparatus includes means for reproducing the fields of the recorded video signal by duplicating every fifth reproduced field.  
     
     
         33 . A method of post-production of one or more signals as claimed in    claim 1   , comprising the steps of: 
 converting the or each signal to a second 60 field/s video signal by a conversion method comprising the step of duplicating every fourth field of the unconverted signal; and    editing the converted signals.    
     
     
         34 . A method of post-production of one or more signals as claimed in    claim 1   , comprising the steps of: 
 converting the or each signal to a second 60 field/s video signal by a conversion method comprising duplicating every fourth field of the unconverted signal and keeping track of the duplicated fields; and    editing the converted signals;    wherein, when two or more of the converted signals are to be combined, the duplicated fields are synchronised.    
     
     
         35 . A method of post-production of one or more signals as claimed in    claim 1   , comprising the steps of: 
 converting the or each signal using apparatus for reproducing a 60 field/s video signal from a recording of the unconverted signal, which apparatus includes means for reproducing the fields of the recorded video signal and duplicating every fourth reproduced field; and    editing the converted signals.    
     
     
         36 . A method of post-production of one or more signals as claimed in    claim 1   , comprising the steps of: 
 converting the or each signal using apparatus for reproducing a 60 field/s video signal from a recording of the unconverted signal, which apparatus includes means for reproducing the fields of the recorded video signal at 48 field/s, means for duplicating every fourth field to provide a field rate of 60 field/s, and means for keeping track of the duplicated fields; and    editing the converted signals;    wherein, when two or more of the converted signals are to be combined, the duplicated fields are synchronised.    
     
     
         37 . A recording of a signal as claimed in    claim 1   .  
     
     
         38 . An apparatus for reproducing a video signal recorded on a medium in a 60 field/s format, comprising: 
 means for controlling a play speed of the recording medium;    means for reproducing fields of the video signal recorded on the medium; and    means for buffering and outputting, at 60 field/s, fields of the reproduced signal;    wherein the speed controlling means and field buffering means are operable in at least one of the following modes, including at least one of modes (A), (B), (D) and (E):    (A) the play speed is 75 field/s and four out of every five reproduced fields are output;    (B) the play speed is 72 field/s and five out of every six reproduced fields are output;    (C) the play speed is 60 field/s and all of the reproduced fields are output;    (D) the play speed is 50 field/s and all of the reproduced fields are output together with one out of every five reproduced fields which is duplicated; and    (E) the play speed is 48 field/s and all of the reproduced fields are output together with one out of every four reproduced fields which is duplicated.