Mixer control apparatus and method

Abstract

 A touch screen interface of a tablet computer is used as a control device for an audio mixer. The screen layout, represented generally at 10, is representative of a football pitch 12. Around the perimeter 14 of the pitch, at various locations, are indicators 14, which comprise circles that are filled with shading to differing extents. In use, the indicators 14 represent the physical positions around a real football pitch at which microphones are located. The extent to which the circle indicators are filled with shading is indicative of a level of signal currently derived from a particular microphone.
At any particular time several microphones may provide a signal level greater than zero. The signals from all of the microphones are mixed in an audio mixer (not shown).
The level of signal to be derived from each microphone is dependent upon an operator action, which can be given by touching the screen at a particular point, such as point X indicated in the drawing. The coordinate location of position X, as touched by the operator, is used to determine, by an algorithm, the levels of all of the microphones.

Description

[0001] The present invention relates to apparatus and a method for controlling a signal mixer, and is concerned particularly, although not exclusively with apparatus and a method of controlling an audio signal mixer.

[0002] When sound is to be recorded or broadcast from a large-area event, such as from a sporting event, multiple microphones are often positioned at various locations around the venue. Signals from the microphones are relayed to an audio mixing device under the control of a skilled operator. The operator will typically observe the event either directly or via a monitor, and will adjust levels of signal from the different microphones in accordance with the action taking place.

[0003] In the example of a football match, microphones will be positioned at various locations beside the pitch, including typically at the corners, beside or behind the goals, close to the dugouts and at a higher level for crowd noise. During the course of the match the operator will monitor the action and will operate a set of faders, each controlling the level of one of the microphones, so as to obtain an optimum combination of sounds from the match, including for example the sound of the ball being struck, the sounds of the players' voices, comments from the coaching staff in the dugout and the crowd noise in the background. The optimum level settings for the individual microphones, for broadcast purposes, will change continuously during the course of the match, and a skilled operator will be constantly adjusting the faders on the mixing desk to maintain the optimum output. However, it is a difficult task to adjust a relatively large number of faders in response to a rapidly changing event. Furthermore, the contribution made by each microphone to the overall audio output is not easy to appreciate merely by looking at a row of faders.

[0004] Embodiments of the present invention aim to provide a control apparatus and method which address some of the disadvantages of the prior art.

[0005] The present invention is defined in the attached independent claims, to which reference should now be made. Further, preferred features may be found in the sub-claims appended thereto.

[0006] According to one aspect of the present invention, there is provided a control device for controlling a mixer arranged to receive a plurality of input signals from a plurality of sensors, the control device having a control interface having a plurality of positions that correspond to physical locations of at least some of the sensors, wherein the control interface is operable by a user to generate an output control signal for the mixer in response to user interaction with the interface.

[0007] The control device preferably has a display for displaying a representation of the physical locations of at least some of the sensors. The control interface may include the display.

[0008] In a preferred arrangement the control interface comprises a touch screen interface.

[0009] The control interface may be arranged to be responsive to a user action comprising physical contact such as a touch and/or stroke. Alternatively, or in addition, the control interface may be arranged in in use to be responsive to other user actions, such as proximity of the user, or movement of the user, or of part of the user, with respect to the control interface.

[0010] The mixer may comprise an audio mixer. At least some of the sensors may comprise microphones.

[0011] The control device is preferably arranged to output one or more control signals which may control one or more output signal level controllers. Preferably the control device is arranged to output one or more signals which may control the position of one or more physical signal level controller devices, such as faders.

[0012] The device is preferably arranged to provide an indication, preferably a visual indication, of one or more levels of one or more of the signal controllers.

[0013] The invention also includes a method of controlling a mixer arranged to receive a plurality of input signals from a plurality of sensors, the method comprising generating an output control signal by interacting with a control interface having a plurality of positions that correspond to physical locations of at least some of the sensors.

[0014] The method may include interacting with the control interface whilst observing the physical locations of at least some of the sensors.

[0015] In a preferred arrangement the method comprises interacting with the control device by touching a touch screen interface.

[0016] Alternatively or in addition the method may comprise interacting with the control device by other user action, such as, but not limited to, varying the proximity or movement of the user, or of part of the user, with respect to the control interface.

[0017] The method preferably comprises a method of controlling an audio mixer, and at least some of the sensors may comprise microphones.

[0018] The method may comprise interacting with the control device to output one or more control signals for controlling one or more signal controllers, such as controlling the position of one or more physical signal level devices, which may include faders.

[0019] The invention also provides a computer program product comprising computer program code which, when said computer program code is run on a computer, is arranged in use to perform a method of controlling a mixer arranged to receive a plurality of input signals from a plurality of sensors, the method comprising generating an output control signal by interacting with a control interface having a plurality of positions that correspond to physical locations of at least some of the sensors.

[0020] One or more sensors may have their level fixed at least temporarily. This allows a user to maintain the level of one or more sensors whilst others are varied.

[0021] One or more sensors may have an offset value, or a predetermined maximum or minimum value, associated with it.

[0022] A transition between sensors may be arranged to be predetermined. The transition may be according to pre-stored settings. This may allow a user to ensure a smooth transition between sensors. A fading-out of a signal from one sensor may be arranged to take place over a fixed duration, which duration is preferably definable by a user. A fading-in of a signal from another sensor may be arranged to take place over a fixed duration, which duration is preferably definable by a user.

[0023] The invention may include any combination of the features or limitations referred to herein, except such a combination of features as are mutually exclusive, or mutually inconsistent.

[0024] A preferred embodiment of the present invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings, in which:

Figure 1 shows schematically a user interface of a control device according to an embodiment of the present invention;

Figure 2 is a schematic diagram of a control system according to another embodiment of the invention; and

Figure 3 shows an alternative user interface of the control device for use in the system of Figure 2.

[0025] Embodiments of the present invention provide apparatus and a method for controlling the signals levels of input signals into a mixing device from a plurality of sources, such as a plurality of microphones. The apparatus outputs control signals that can be used to drive - ie preferably physically move - faders on the mixing device. In the example given below the control device is realised in application software loaded onto a tablet computer having a touch screen interface. However, the interface could equally utilise gesture recognition or other non-tactile interaction.

[0026] Figure 1 shows schematically a touch screen interface of a tablet computer as a control device according to an embodiment of the invention. The screen layout, represented generally at 10, is in this example representative of a football pitch 12. Around the perimeter 14 of the pitch, at various locations, are indicators 14, which comprise circles that are filled with shading to differing extents. In use, the indicators 14 represent the physical positions around a real football pitch at which microphones are located. The extent to which the circle indicators are filled with shading is indicative of a level of signal currently derived from a particular microphone.

[0027] As can be seen from the example of Figure 1, at any particular time several microphones may provide a signal level greater than zero. The signals from all of the microphones are mixed in an audio mixer (not shown).

[0028] The level of signal to be derived from each microphone is dependent upon an operator action, which can be given in this example by touching the screen at a particular point, such as point X indicated in the drawing. The coordinate location of position X, as touched by the operator, is used to determine, by an algorithm, the levels of all of the microphones. If the operator's finger is dragged along to position Y, in a locus indicated by the broken line, the levels of the microphones are adjusted, according to the algorithm.

[0029] The algorithm optimises the sound output from the combined set of microphones according to the position chosen by the operator as a point of interest (POI) on the screen. The operator indicates a POI based upon monitoring the action of a match taking place on the real football pitch.

[0030] The operator may, for example, observe that the ball has moved from a physical location approximately represented as position X on the screen, to a physical location approximately represented as position Y on the screen and accordingly drags a finger from X to Y. The algorithm reacts by altering the relative signal levels from several microphones. In the example given, position Y is closer to one of the goal areas 16 than is position X. As a result, the levels of microphones closer to area 16 are selected to be raised, and others reduced.

[0031] The control device, which in this case is a tablet computer having the screen 10, outputs control signals to an audio mixer (not shown) where the signals are interpreted and used to drive faders which themselves control the signals from the separate microphones in order that the mixer should be able to output an optimised mixed signal reflecting the action on the football pitch, for example for recording or broadcast.

[0032] In fact the algorithm is able to handle several POIs at the same time, which may be indicated by the operator by touching several positions within the screen simultaneously or else by creating a succession of "live" POIs. This may be required, for example, when a goal has been scored and the operator wishes to pick up both the crowd celebrations and also any dialogue from the coaches.

[0033] Because the indicators 14 show not just that a particular microphone is active, but also the level at which it is active, the operator is afforded a graphic representation of the contributions to the output signal made by each of the microphones, which would be less easy to comprehend merely by looking at a row of faders. The indicators 14 should also indicate the direction of each microphone, since the responses of certain types of microphone are highly directional.

[0034] Also, the apparatus can have pre-stored optimum settings for different venues or venue types, and also for different events or event types, as well as pre-set optimised levels for different types of incident within an event, such as a kick-off, a corner kick or a goal in the example of a football match.

[0035] Furthermore, for each microphone, the user can choose to prevent the system from sending level values to the corresponding fader. This is so the user can choose to leave certain microphones open (if there is action they want to capture at a static location while mixing elsewhere) or closed (if there is swearing or a faulty microphone that they never want to be part of the mix).

[0036] Also, each microphone can have an offset associated with it, such that when its corresponding fader level is set, it can be higher or lower than other faders for equivalent weight in the calculation. The offset can be permanent until removed by the user, or automatically removed when a new POI is located.

[0037] The apparatus may also have pre-stored settings that govern the transitions between sensors, so that when the operator selects a new POI the sensors fade smoothly from one to the other. A cross-fade setting can also be employed.

[0038] This can be useful, since applying new fader levels at the instant a new POI is registered may be problematic. If the new POI is at a significantly different location to the previously active POI, an abrupt change in levels can create a significant and abrupt change in the audio. An example is an exiting POI that has been left (user touch removed) from the left goal. A new POI is created by tapping near the right goal. The system reacts quickly and results in an abrupt change in audio content. The crowd noise and ambience changes completely which is unacceptable for broadcast quality output. To manually smooth the transition, the user could drag the POI from one goal to the other, but this would have the effect of raising and lowering every microphone the POI passes, also creating unwanted changes in the audio.

[0039] Accordingly, when the user inputs a new POI, the resultant levels applied to each fader may not be applied instantly. There may be a user definable fade duration. The levels applied by the new touch will fade in over this duration, creating a smooth sounding transition which more closely emulates a manual fader mix. The user can input a POI at one goal, then input a new POI at the other goal. The old POI fades out and the new POI fades in, with a pleasing and smooth transition and without involving any other microphones in between. The fade in duration applies to new static POIs, or to new POIs that the user moves around the pitch - i.e. moves do not cause an abrupt change in the audio either. Each active POI has its own fades applied, so it is possible to be moving one POI, while adding another, each fading in and out smoothly as they become active or inactive. The last POI is never removed to prevent audio dropping out completely but is considered inactive - a new POI will remove it.

[0040] Optionally the operator may expand the POI, for example using a finger spreading action, so that the selected POI may affect more sensors, or different sensors, or may change the levels of active sensors. The operator may select one or more sub-fields within the field of the event. This may be achieved using one or more physical gestures, such as finger spreading or stroking the interface. Once selected, the sub-fields may be allocated control criteria which affect the operation of the sensors within, or in proximity to, a particular field.

[0041] A master fader device, represented as an interactive sliding or rotary control on the display, may be used to control the overall levels from the sensors.

[0042] An automated tracking apparatus may be used, which monitors an object or person within an event space, and automatically tracks the object's position. The automated tracking apparatus may automatically determine one or more POIs based upon the detected position of a tracked object, or objects, and the algorithm will adjust the signal levels of several microphones accordingly. The operator may override the automated tracking at any time, for example by touching the screen 10, or else by touching one or more of the faders on the mixer.

[0043] Figure 2 shows schematically such an alternative embodiment. The screen layout is denoted as 20 and the automated tracking device is represented by 22. A mixing algorithm is depicted at 24 and an audio mixer console is shown at 26. The algorithm 24 and screen layout 20 are preferably stored on a computer, such as a tablet computer (not shown), having a touch screen interface.

[0044] In use, the tracking system provides positional information about one or more objects to the algorithm 24. The algorithm 24 extracts positional and/or other information about the objects, and converts this into one or more POIs.

[0045] It then sends an interface signal so that the screen 20 is able automatically to indicate the position(s) of the object(s), and also indicate the determined levels for each of the level indicators 14.

[0046] At the same time the algorithm sends control signals to the audio console 26 to control the levels of the real microphones, which may be by controlling the physical positions of multiple faders (not shown) on the console, and to adjust other controls as necessary to affect the audio output of the console in real time.

[0047] At any time a user, represented at 28, is able manually to override both the console 26, by physically adjusting the positions of the faders, and also the interface, by touching the screen 20.

[0048] Figure 3 shows an alternative layout, for example for display on a touch screen interface. The screen, generally represented at 30, depicts a golf course in this example. Each hole of the course is represented by a slider track 32 as a control for a plurality of microphones located along a hole of a real golf course. The operator specifies how many microphones are available at each hole, and how far along the hole each microphone is located.

[0049] Once play is underway along a particular hole the operator moves a slidable control 34 to determine where on that particular hole he wishes to listen, with one end 32a of the track representing the tee, a middle portion 32b representing the fairway, and an opposite end 32c representing the green. Output levels for the microphones at each location along the hole are optimised by the algorithm 24 according to the position of the control 34 along the slider track 32. Individual microphone levels can be depicted on the screen 30 to provide the operator with more detailed visual feedback about the audio context if desired.

[0050] Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance, it should be understood that the applicant claims protection in respect of any patentable feature or combination of features referred to herein, and/or shown in the drawings, whether or not particular emphasis has been placed thereon.

Claims

1. A control device for controlling a mixer arranged to receive a plurality of input signals from a plurality of sensors, the control device having a control interface having a plurality of positions that correspond to physical locations of at least some of the sensors, wherein the control interface is operable by a user to generate an output control signal for the mixer in response to user interaction with the interface.

2. A control device according to Claim 1, wherein the control device is arranged to output one or more control signals which may control one or more output signal level controllers.

3. A control device according to Claim 1, wherein the control interface comprises a touch screen interface.

4. A control device according to any of the preceding claims, wherein the mixer comprises an audio mixer, and at least some of the sensors comprise microphones.

5. A control device according to Claim 4, wherein each microphone can have an offset associated with it, such that when its corresponding level is set, it can be higher or lower than other levels.

6. A control device according to any of Claims 1-4, wherein the device contains pre-stored settings that govern transitions between sensors.

7. A control device according to any of the preceding claims, wherein the device is arranged to provide an indication, preferably a visual indication, of one or more levels of one or more of the signal controllers.

8. A method of controlling a mixer arranged to receive a plurality of input signals from a plurality of sensors, the method comprising generating an output control signal by interacting with a control interface having a plurality of positions that correspond to physical locations of at least some of the sensors.

9. A method according to Claim 8, wherein the method comprises interacting with the control interface to output one or more control signals for controlling one or more signal controllers, such as controlling the position of one or more physical signal level devices, which may include faders.

10. A method according to Claim 8 or 9, wherein the method includes interacting with a touch screen as the control interface, whilst observing the physical locations of at least some of the sensors.

11. A method according to any of Claims 8 to 10, wherein the method comprises a method of controlling an audio mixer, and at least some of the sensors may comprise microphones.

12. A method according to Claim 11, comprising predetermining settings that govern transitions between sensors.

13. A computer program product comprising computer program code which, when said computer program code is run on a computer, is arranged in use to perform a method of controlling a mixer arranged to receive a plurality of input signals from a plurality of sensors, the method comprising generating an output control signal by interacting with a control interface having a plurality of positions that correspond to physical locations of at least some of the sensors.

14. A computer program product according to Claim 13, arranged to perform a method according to any of Claims 8-12.

Drawing