Abstract:
A method and system for visually signaling the selection of a specific television or video camera source during the live editing of multiple camera sources is disclosed. The system includes an adapter and a power console in combination for receiving a plurality of tally signals from a video switcher and converting each of the tally signals into an encoded sub-audible Continuous Tone Control Squelch System tone. The system also includes a tally system having a plurality of belt-pack assemblies for receiving the encoded sub-audible CTCSS tone and illuminating tally lights corresponding to the camera selected by the switcher.

Description:
This application claims the benefit of U.S. Provisional Application No. 60/285,277 filed Apr. 20, 2001. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to multiple camera video production, and more specifically to a method and system for visually signaling the selection of a specific television or video camera source during the live editing of multiple camera sources. 
     BACKGROUND OF THE INVENTION 
     Traditional multiple camera video production systems include analog cameras connected to a video switcher via multiple conductor camera cable. This traditional production system includes an additional fundamental feature, the “tally light” system. The tally light system tells both the individual camera operators and any on-camera talent being photographed which camera is “on” or “live.” 
     The signals for the tally light feature are sent from the switcher to the cameras down a separate electrical wire contained within the multiple conductor camera cables. The tally light information derived from these tally signals follows exactly the sequence of cameras selected by the person pressing the switch, which selects the “live” camera. The tally signals selectively activate lights in both the camera viewfinder for the camera operator to become aware of when their particular camera is selected and in front of the camera so that talent being photographed will know which camera has been selected and is photographing the scene at that very moment. 
     A new single screen live video editor was described in U.S. patent application Ser. No. 10/081,543, filed Feb. 20, 2002, entitled “PORTABLE SYSTEM FOR LIVE TELEVISION SIGNAL EDITING.” by Edmond Louis Dudkowski. The video editor described in this patent application is a “plug and play” system that accepts both analog and digital video input signals from a plurality of single video camera shooting equipment (“camcorders”), both “prosumer” (professional level) and consumer. The system then allows a user to use a switcher to edit these input signals, and the system then enables each input signal, as well as a preview and a program signal, to be simultaneously viewed on a single display monitor. 
     Just as switchers in traditional multiple camera video production systems, the switcher in this new system generates tally signals. However, the traditional tally light system will not work when camcorders are used as the video input source. Specifically, when camcorders are used as an input source to this new live video editor, multiple conductor cable is unnecessary because only video signals are available from the cameras. The elimination of the multiple conductor camera cable between the camera and the switcher also eliminates the tally light system. 
     What is needed is a system for visually showing camera operators when their signal is “live” and for showing on-camera talent which camera is photographing them at any given moment, without the need for multiple conductor camera cable to be returned to the camera. 
     SUMMARY OF THE INVENTION 
     The present invention is directed at addressing the above-mentioned shortcomings, disadvantages and problems of the prior art. The present invention describes a system for camera selection tallying for multiple camera video production comprising: an adaptor for receiving a plurality of tally signals generated in a switcher, each said tally signal generated in response to a given camera being selected, said adaptor further configured for converting each said received tally signal into an encoded signal having data that identifies an address that corresponds to the selected camera; a tally system for decoding each said encoded signal to retrieve the address data and for displaying at least one visual indicator associated with said address data that identifies the corresponding camera that was selected; and a power console coupled between said adaptor and said tally system for coupling each said encoded signal from said adaptor to said tally system. 
     The adapter is further configured to convert each tally signal into a corresponding sub-audible CTCSS tone and further to encode the CTCSS tone with data that identifies a CTCSS code address that corresponds to the selected camera. The power console provides a power supply source and has at least two frequency channels, wherein at least one channel has an intercom line for two-way communication between a director and a plurality of camera operators. The power console provides power to the adapter and is configured to forward the encoded sub-audible CTCSS tone through the intercom line to each of a plurality of belt-packs in the tally system, each belt-pack being connected in parallel to the power console and each having a dipswitch for setting the belt-pack to a given CTCSS code address corresponding to a given camera. Each belt-pack is further configured to receive the encoded sub-audible CTCSS tone from the intercom line, separate the encoded data from the sub-audible CTCSS tone, compare the retrieved data to the belt-pack&#39;s CTCSS code (or “dipswitch”) address, and illuminate a series of light emitting diodes (“LEDs”) connected to the belt-pack if the retrieved data matches the CTCSS code address. 
     The present invention also describes a method for camera selection tallying for multiple camera video production comprising: (a) causing a tally signal to be received into an adaptor, said tally signal generated in response to a given camera being selected; (b) causing said tally signal to be converted by said adaptor into an encoded signal having data that identifies an address that corresponds to the selected camera; (c) causing said tally signal to be coupled from said adaptor to a tally system using a power console; (d) causing said encoded signal to be decoded to retrieve the address data; and (e) causing a visual indicator associated with said address data to be displayed for identifying the corresponding camera that was selected and repeating steps (a)-(e) until said video production has ceased. 
     The primary object of the present invention is to provide a tally light system without the need for multiple conductor cable. A key advantage of the present invention is that a tally light system can be utilized with a multiple camera video production system that uses prosumer and consumer camcorders, where a tally light system would not otherwise exist. 
    
    
     BRIEF DESCRIPTIONS OF THE DRAWINGS 
     The foregoing aspects and attendant advantages of the present invention will become more readily apparent by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein: 
     FIG. 1 is a block diagram of a system for camera selection tallying for multiple camera video production according to a preferred embodiment of the present invention. 
     FIG. 2 is a block diagram illustrating the elements of Adapter  110  and Power Console  120 , of System  100  illustrated in FIG. 1, which are used to accept a tally signal and output a corresponding encoded sub-audible CTCSS tone. 
     FIG. 3 is a block diagram illustrating the elements of a Belt Pack  150 , of System  100  illustrated in FIG. 1, which is used to accept an encoded sub-audible CTCSS tone and activate one or more LEDs if the encoded data matches the CTCSS code address. 
     FIG. 4 is a flow diagram illustrating the steps for camera selection tallying for multiple camera video production performed by the preferred system illustrated in FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 is a block diagram of a system for camera selection tallying for multiple camera video production according to a preferred embodiment of the present invention. System  100  preferably includes an Adapter  110 , a Power Console  120 , and a Tally System  130 , which is comprised of a plurality of tally subsystems  140  that each include a Belt-Pack  150 , which drives one or more LEDs (or “tally lights”), and a Headset  160 . 
     Adapter  110  has a plurality of logic input leads to receive a plurality of tally signals  10  from a video switcher. Each tally signal is typically a voltage across a tally LED in the switcher, which is generated when a switcher operator selects a corresponding camera. Adapter  110  also has a micro-controller (microprocessor or converter circuit) that preferably converts each tally voltage signal into a Continuous Tone Control Squelch System (CTCSS) tone that is compatible with Power Console  120 . The System Adapter PCA model SA100 manufactured by Smartsciences is one example of an adapter that could be used in a preferred embodiment of the present invention. 
     Power Console  120  is preferably connected to Adapter  110  via a personal computer board multiple pin edge connector such as a Panduit or similar connector. Power Console  120  is a conventional private-line (P-L) voice communication system power console preferably having at least two audio frequency channels, wherein at least one channel is configured for transmitting CTCSS tones on an intercom line dedicated to two-way communications between a director and a plurality of camera operators. For example, in live television production, the director uses the P-L system to give the camera operators voice audio instructions about movements such as zooming, panning, tilting and framing. Power Console  120  further supplies a direct current (“DC”) power source to Adapter  110  and to each Belt-Pack  150 . 
     During P-L communications, the CTCSS provides a way to differentiate each camera operator since all of the camera operators use a single frequency to communicate with the director. To enable each camera operator to be identified within the System  100 , each camera operator has equipment that is assigned a different CTCSS code address which corresponds to a different sub-audible CTCSS tone. As set forth more fully below and as illustrated in FIGS. 2 &amp; 3, the present invention uses the sub-audible CTCSS tones generated by Adapter  110  and forwarded through Power Console  120  to operate the tally lights within Tally System  130 , in order to indicate which camera is live. 
     Referring again to FIG. 1, Tally System  130  consists of a plurality of tally subsystems  140  for P-L communications and for tally indication. Each subsystem  140  contains a Belt-Pack  150  that receives the sub-audible CTCSS tones from Power Console  120  coupled to a Headset  160 . System  100  contains a minimum of one tally subsystem for each camera operator. Power Console  120  is preferably connected in parallel to each Belt-Pack  150  through an industry standard three-conductor audio (microphone) cable and corresponding connectors. 
     FIG. 2 is a block diagram illustrating the elements of Adapter  110  and Power Console  120 , of System  100  illustrated in FIG. 1, which are used to accept a tally signal and output a corresponding encoded sub-audible CTCSS tone. The elements of Adapter  110  used to receive and convert the tally signals are shown in FIG. 2 within the dotted lines. These elements include Protective Circuitry  111 , a Tally LED Sense circuit  112 , a Microcontroller  113 , an Encoder  114  and a Low Pass Filter  115 . FIG. 2 also shows the elements of Power Console  120  used to route an encoded sub-audible CTCSS tone to Tally System  130 . These elements include an Intercom Channel  121 , an Intercom Channel  122  and a Power Source  123 . 
     Adapter  110  is a printed circuit assembly (“PCA”) that uses conventional Protective Circuitry  111  to shield the PCA while receiving a tally signal voltage. Tally LED Sense circuit  112  preferably comprises ten tally input leads for receiving each of a plurality of tally signals. Each tally input lead is coupled to a separate voltage output from the switcher, wherein each switcher output emits a tally signal voltage that corresponds to a particular camera being selected. More or fewer tally input leads can be used depending upon the number of cameras used to shoot an event or other production. Micro-controller  113  serves as the microprocessor and controller for Adapter  110 . Micro-controller  113  converts the tally signal into a corresponding sub-audible CTCSS tone depending upon which input lead the voltage is received from. Encoder  114  then encodes the CTCSS tone, using conventional methods known in the art, with data which identifies a CTCSS code address corresponding to the camera selected. This encoded sub-audible CTCSS tone then passes through Low Pass Filter  115  for noise removal into either Intercom Channel  121  or Intercom Channel  122  to be forwarded to Tally System  130 . 
     Intercom Channels  121  &amp;  122  are preferably line drivers and accept both verbal information that has been converted by Power Console  120  into an audio signal and the encoded sub-audible CTCSS tone. Preferably a combined encoded sub-audible CTCSS tone and audio signal is sent by either Intercom Channel  121  or  122  down the three conductor microphone cable to each Belt-Pack  150  in Tally System  130 . Power Console  120  also preferably comprises a Power Source  123  that supplies a 12 volt DC power source to Adapter  110  and a 5 volt DC power source to each Belt-Pack  150 . 
     FIG. 3 is a block diagram illustrating the elements of a Belt Pack  150 , of System  100  illustrated in FIG. 1, which is used to accept an encoded sub-audible CTCSS tone and activate one or more LEDs coupled to the Belt-Pack  150  if the encoded data matches the belt-pack&#39;s CTCSS code address. Each Belt-Pack  150  preferably includes a Buffer  151 , Talk-off Filters  152  &amp;  153 , a Decoder  154  having a Clock Oscillator  155 , an Address Dipswitch  156  and a Dual Lamp Driver  157 . 
     The combined encoded sub-audible CTCSS tone and audio signal from either Intercom Channel  121  or  122  of Power Console  120  is received into Buffer  151 , which is a conventional buffer stage. The combined signal then passes through Talk-off Filters  152  and  153  to separate the encoded sub-audible CTCSS tone from the audio signal. Decoder  154  receives the encoded sub-audible CTCSS tone and, with Clock Oscillator  155  and using conventional methods known in the art, demodulates the encoded sub-audible CTCSS tone to retrieve the encoded data. 
     Decoder  154  is preferably further configured to compare the retrieved CTCSS code address data with the setting of the six-position Address Dipswitch  156 . Address Dipswitch  156  sets the CTCSS code address for Belt-Pack  150 , which is used to identify the camera associated with that belt-pack. If the retrieved CTCSS code address data matches the dipswitch address, then Decoder  154  activates the Dual Lamp Driver  157  which illuminates one or more tally lights, each tally light being an LED connected to Belt-Pack  150 . The illuminated tally lights indicate which camera was selected by the switcher and is, therefore the live camera. 
     Preferably an LED is connected via a cable to a jack at the rear of Belt-Pack  150 , and this LED is mounted on a small box which may be attached by conventional means, such as Velcro, hoop, or loop fastener, to a surface on or near the camera. Another LED is preferably mounted on a small clip which may be clipped onto a microphone boom of Headset  160  so that the camera operator may see the illuminated LED through his or her peripheral vision while watching the camera viewfinder. Additional LEDs may be used and may be located in various locations to indicate to both on-camera talent and the camera operators which camera is live. 
     Belt-Pack  150  is also configured for conventional P-L communications. Therefore, Belt-Pack  150  further preferably includes a volume control for the user to adjust headset audio levels and also includes two switches. One switch is preferably used to turn the headset microphone on to speak, or off to reduce overall ambient noise in the system. The other switch is used to switch between Intercom Channels  121  and  122  of Power Console  120 . If one channel is being used for a camera operator to communicate to the director, the other channel allows the other users on the P-L system to communicate with each other. Each Belt-Pack  150  also preferably includes: a rear panel having a connector for connecting to the intercom channels and power supply of Power Console  120 ; a headset connector; and jacks to connect the tally lights. 
     FIG. 4 is a flow diagram illustrating the steps for camera selection tallying for multiple camera video production performed by the preferred system illustrated in FIG.  1 . Once video production of an event begins, a switcher operator selects a given “live” camera from a plurality of cameras taping the event. As this occurs, the switcher simultaneously produces a voltage across an LED, the “tally signal.” At step  410 , Adapter  110  receives a tally signal into one of its logic input terminals, and at step  420 , the micro-controller of Adapter  110  converts this tally signal into one of a plurality of sub-audible CTCSS tones depending upon which camera was selected. Adapter  110  then encodes the sub-audible CTCSS tone with data that identifies a CTCSS code address corresponding to the camera selected, at step  430 . This CTCSS code address also corresponds to the dipswitch setting of a Belt-Pack  150  in a given tally subsystem  140 . The dipswitch for each Belt-Pack  150  in Tally System  130  is previously set to a different CTCSS code address corresponding to a different sub-audible CTCSS tone, to identify each individual camera operator. 
     Power Console  120  receives the encoded sub-audible CTCSS tone and couples it through an intercom line to each Belt-Pack  150 , at step  440 . Each Belt-Pack  150  receives the encoded sub-audible CTCSS tone, and the decoder of each Belt-Pack  150  separates the encoded data from the sub-audible CTCSS tone, at step  450 . The decoder then compares the data retrieved with its dipswitch address, at step  455 . At step  460 , the Belt-pack  150  having a dipswitch address that matches the retrieved address data activates its LEDs. If it is determined at step  470  that video production has ended, then Process  400  ends. Otherwise, Process  400  repeats beginning with step  410 . 
     In another embodiment of the present invention, each belt-pack receives the encoded sub-audible CTCSS tone without the use of a three connector microphone cable. In this embodiment, the power console is configured to transmit the encoded sub-audible CTCSS tone as a wireless radio frequency, and the belt-pack is configured to receive the encoded sub-audible CTCSS tone as a wireless radio frequency. This wireless embodiment of the current invention functions similarly in all other respects as the preferred embodiment described above. 
     The implementation examples of a method and system for camera selection tallying for multiple camera video production were chosen as being illustrative of the best mode of the present invention. All embodiments of the present invention described above are illustrative of the principles of the invention and are not intended to limit the invention to the particular embodiment described. Accordingly, while the preferred embodiment of the present invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.