WO2016079526A1

WO2016079526A1 - A distributed audio signal processing apparatus

Info

Publication number: WO2016079526A1
Application number: PCT/GB2015/053532
Authority: WO
Inventors: John Patrick Warrington; Peter Walker
Original assignee: Calrec Audio Limited
Priority date: 2014-11-22
Filing date: 2015-11-19
Publication date: 2016-05-26
Also published as: GB201420787D0; EP3221986A1; GB2533548A

Abstract

A distributed audio signal processing apparatus comprising at least two programmable signal processing blocks, each signal processing block comprising a routing matrix comprising a plurality of matrix inputs and at least one matrix output, each matrix input having a channel connected thereto; and, a plurality of audio input ports a control console connected to each of the signal processing blocks the control console comprising a plurality of controls and a user interface, the control console being adapted to communicate with each of the signal processing blocks to determine the audio input ports, channels and matrix outputs of the signal processing blocks and to display at least the audio input ports and matrix outputs in the interface; the control console being further adapted to create at least one audio route in at least one signal processing block based on selection of an audio input port and at least one matrix output in the interface, the audio route extending from the selected audio input port, through a channel and associated matrix to the at least one selected matrix output, and to further connect a control to the channel in the audio route.

Description

A distributed audio signal processing apparatus

The present invention relates to a distributed audio signal processing apparatus. More particularly, but not exclusively, the present invention relates to a distributed audio signai processing apparatus wherein at least two programmable signal processing blocks can be controlled by the same control console.

TV production outside of a TV facility is an expensive business due to the logistics of transporting and supporting specialist staff and equipment. With ever increasing competition broadcasters are seeking to make cost savings without compromising quality or technical capability. Improvements in speed and bandwidth of IP networking technology allow for reliable remote control of equipment, reducing technical staffing requirements on location but increasing the burden of complexity on engineering staff within the broadcast facility.

It can be very difficult to learn how to use a control console (also known as a mixing console). It can take several months or more for an operator to become proficient in the use of a control console. There is no standard design for control consoles with each manufacturer using a different design. This can cause a problem when a single operator within a broadcast facility is attempting to operate control consoles for both local and remote mixers simultaneously and trying to produce audio mix for consumption in the broadcast studio and a separate mix for consumption remotely. This can often be simply too difficult for an operator to achieve.

The present invention seeks to overcome the problems of the prior art.

Accordingly, the present invention provides a distributed audio signal processing apparatus comprising

at least two programmable signal processing blocks, each signai processing block comprising a routing matrix comprising a plurality of matrix inputs and at least one matrix output, each matrix input having a channel connected thereto; and, a plurality of audio input ports

a control console connected to each of the signal processing blocks the control console comprising a plurality of controls and a user interface, the control console being adapted to communicate with each of the signal processing blocks to determine the audio input ports, channels and matrix outputs of the signal processing blocks and to display at least the audio input ports and matrix outputs in the interface;

the control console being further adapted to create at least one audio route in at least one signal processing block based on selection of an audio input port and at least one matrix output in the interface, the audio route extending from the selected audio input port, through a channel and associated matrix to the at least one selected matrix output, and to further connect a control to the channel in the audio route.

This distributed audio signal processing apparatus according to the invention considerably simplifies work flow and makes such a complex system manageable. The operator is always faced with the same familiar interface and controls irrespective of the signal processing blocks which make up the distributed system.

Preferably the distributed audio signal processing apparatus comprises at least one audio route, each audio route extending within one signal processing block.

Preferably the matrices are connected together by a mixing bus. Preferably the distributed audio signal processing apparatus comprises at least one audio route, the at least one audio route extending from one signal processing block across the mixing bus to another signal processing block

Preferably the matrices perform local mixing.

Preferably the matrices are slaved together over the mixing bus such that the outputs for each matrix are the same.

Preferably each matrix performs a local mix of signals from audio input ports in the same signal processing block as the matrix which are destined for the same matrix output and provides this partial mix to the mixing bus, and if a partial mix is available on the mixing bus for that matrix output it combines it with its own local mix to produce a final mix at the local version of the matrix output.

Preferably each matrix output is connected to an output processor for processing the mixed audio output from the matrix output.

Preferably the output processor connected to the matrix output of one signal processing block is slaved with the output processor of the corresponding matrix output of the other signal block such that the two output processors process the mixed audio signals they receive identically.

Preferably the interface further displays the channels of the signal processing blocks, the created audio route including the channel selected in the interface.

Alternatively the control console automatically determines the channel to include in the audio route. Preferably the distributed audio signal processing apparatus further comprises an audio source connected to an audio input port.

The present invention will now be described by way of example only and not in any limitative sense with reference to the accompanying drawings in which

Figure 1 shows in schematic form a known distributed audio signal processing apparatus;

Figure 2 shows a first embodiment of a distributed audio signal processing apparatus according to the invention;

Figure 3 shows a second embodiment of a distributed audio signal processing apparatus according to the invention;

Figure 4 shows the routing table for the embodiment of figure 3;

Figure S shows a further embodiment of a distributed audio signal processing apparatus according to the invention;

Figure 6 shows the routing table for the embodiment of figure S; and,

Figure 7 shows a further embodiment of a distributed audio signal processing apparatus according to the invention.

Figure 1 shows a known distributed audio signal processing apparatus 1. it is known in the art to arrange for an audio mixer 2 to be arranged at a remote location and second mixer 3 to be arranged in a broadcast studio 4. The mixer 3 in the broadcast studio 4 is controlled iocafty by a control console 5 in the broadcast studio 4. The remote mixer 2 is controlled over the internet 6 by a second control console 7 within the broadcast studio 4.

Such an arrangement is difficult for an operator to manage as may be best explained by way of an example. At a football match there will be several audio sources, typically microphones. One (or in practice several) microphones will pick up the crowd noise. A further microphone will pick up the sound of the match. A further microphone will pick up the voice of the commentator at the match. A mixer 2 remote from the studio 4 at the football ground is used to mix these sounds together for broadcast. This is controlled over the internet 6 by a control console 7 at the broadcast studio 4. There will be further commentators in the local studio. The commentator's voices are mixed by a local mixer 3 for broadcast. This is controlled by a further control console 5 at the broadcast studio.

This can be very difficult for an operator in the broadcast studio 4 to manage. The operator must control two separate control consoles 5,7 simultaneously at least one of which may be unfamiliar to the operator. Further, the two mixes are not independent of each other. For example the remote mix must be further mixed with the local commentator mix before broadcast. Similarly, the local commentator mix must be passed back to the remote location so that the commentator at the match can hear the commentators in the studio 4. A further complication is that the commentator at the match needs to be able to hear himself (and other commentators at the match) talk. The remote mixer 2 must therefore produce a further mix of the commentator's voices that the commentators can hear through their headphones. This must be done remotely (ie at the match) rather than locally at the broadcast studio 4 as a small time delay can be very off putting to a commentator when he or she hears their own voice. Managing all the correct mixes, the relation between them and where they are performed, in real time and with unfamiliar control consoles can be almost impossible to manage even for an experienced operator.

Shown in figure 2 is an embodiment of a distributed audio signal processing apparatus 10 according to the invention. The distributed audio signal processing apparatus 10 comprises first and second programmable signal processing blocks 11,12. Each signal processing block 11,12 comprises a plurality of audio Input ports 13 for receiving audio input from an audio source 14 such as a microphone or the like. Arranged within the signal processing block 11,12 is a routing matrix 15,16 which comprises a plurality of matrix inputs 17 and a plurality of matrix outputs 18. The operation of a routing matrix is well known in the art and so will only be described in outline. Audio inputs at the matrix inputs 17 are mixed together and output at a matrix output 18. The matrix 15,16 is programmable and so different mixes from different combinations of matrix inputs 17 can be made available at different matrix outputs 18. In addition to mixing the signals at the matrix inputs 17 to matrix outputs 18 the matrix 15,16 may also perform additional processing on the signals.

Connected to each matrix input 17 is a channel 19. A channel is a technical term used in the field of audio signal processing. A channel 19 is an electronic circuit used to process a received audio signal and pass it to the associated matrix input 17. A common example of a channel 19 is an amplitude controller, used to adjust the amplitude of the audio signal passed to the associated matrix input 17. In alternative embodiments the channel 19 will perform more complex processing of the received signal. The combination of routing matrix 15,16 and one or more channels 19 is typically referred to as a mixer.

The distributed audio signal processing apparatus 10 further comprises a control console 20. The control console 20 comprises a plurality of controls 21 and an interface 22. The control console 20 is connected to the two programmable signal processing blocks 11,12 by control lines 23,24. Typically the control console 20 is located in a broadcast studio along with one of the signal processing blocks 11. The control console 20 communicates with the local signal processing block 11 over a LAN. The other signal processing block 12 is typically located remotely (for example at a football match or similar). The control console 20 typically communicates with this signal processing block 12 over a WAN .

When the signal processing blocks 11,12 come on line they communicate with the control console 20 so that the control console 20 can determine the audio input ports 13, the channels 19 and the matrix outputs 18 for each signal processing block 11,12. In this embodiment the audio input ports and mixer outputs 18 are shown in the interface 22.

An operator at the console 20 can select an audio input port 13 and matrix output 18 for a signal processing block 11,12 in the interface 22. In this embodiment the audio input port 13 and matrix output 18 must both belong to the same signal processing block 11,12. The control console 20 will then send instructions to the signal processing block 11,12 to create an audio route from the selected audio input port 13, through a channel 19 to a matrix input 17 and then through the matrix 15,16 to a matrix output 18. Typically the control console 20 programmatical!y connects an audio input 13 at the start of the audio route to a channel 19. It then sends instructions to the matrix 15,16 so that audio at the matrix input 17 from the channel 19 is sent the matrix output 18 at the end of the audio route. In this embodiment the control console 20 automatically selects a channel 19 to participate in the audio route. The control console 20 also programmatically connects a control 21 of the control panel 20 to the channel 19 of the audio route. In figure 2 a control 21 on the control console 20 and the channel 19 it controls are identified by the same letter.

By this method the operator can create a plurality of audio routes in each signal processing block 11,12. If two audio routes share the same matrix output 18 then they are mixed by the matrix onto that output 18.

In practice the creation of routes may follow a different pattern. The control console 20 may also display the available channels 19 on the interface 22. The operator may first start by identifying a control 21 in the interface 22 followed by the audio input port 13 and mixer output 18. The control console 20 then creates the audio route and connects the control 21 to the channel 19 employed in the audio route.

Such an apparatus considerably simplifies the job of an operator. Before the start of an event (for example a football match} the local and remote signal processing blacks 11,12 are connected to the control console 20 {in the case of the remote signal processing block 12 this is over the internet 6}. The control console 20 and the signal processing blocks 11,12 communicate as described above enabling the operator to create one or more audio routes as required. The operator can then use a familiar control surface to control the local and remote mixes during an event.

The operator may then be required to mix audio from a different event. The first remote signal processing block 12 is disconnected from the network and a new signal processing block 12 at the new venue connected. As before, the control console 20 detects that the new signal processing block 12 has been added. It then determines the input ports 13, the matrix outputs 18 and the channels 19 for the new signal processing block 12. The operator creates the required audio routes as before and then mixes the sound from the second event. If there are (for example) a different number of microphones at the new event this may translate into a different number of active controls on the control console 20. Similarly, if the new remote signal processing block 12 is more limited in functionality than the original remote signal block 12 then the range of controls 21 available on the control surface may be more limited. However overall, from the point of view of the operator very little has changed. The operator is still using the same familiar set of controls 21 on the same control console 20. This translates to a significant increase in ease of use.

Shown in figure 3 is a more realistic embodiment of a distributed audio signal processing apparatus 10 according to the invention. At the remote venue there are three audio sources - presenter 1, presenter 2 and Venue ambient'. At the local studio there are two miscellaneous audio sources, misc 1 and misc 2. They could for example be presenters local to the studio. The remote presenters desire to be able to hear each other talk and also the venue ambient noise. The remote signal processing block 12 is therefore programmed from the control console 20 in the studio with audio routes as shown producing outputs OP1 and OP2 at the venue to which the presenters can piug in their earphones.

In the studio a different mixing is required. Here a broadcast mix (main 1) is required which is a mix of presenter 1, presenter 2, venue ambient, misc local 1 and misc local 2. Comm 1 and Comm 2 are aiso required corresponding to the voices of presenter 1 and presenter 2 respectively. The local signal processing block 11 is programmed by the control console 20 to provide the appropriate audio routes as shown to achieve this. For both signal processing blocks 11,12 the audio routes only extend within that block 11,12 so all mixing in done 'locally' within one signal processing block 11,12. The audio sources presl, pres 2 and venue ambient are split and fed to both digital signal processing blocks 11,12 as shown to achieve this.

During broadcast it may be necessary to take an output from the local matrix 15 and provide it to the remote matrix 16. For example, the remote presenters may desire to be able to hear the local presenters. In this case the control console 20 programs additional audio routes for misc local 1 and misc local 2 to a new output, misc minus of the local matrix IS. Misc minus is then connected via an IP cloud (not shown) to a matrix input 17 of the remote matrix 16 from where it is provided to OP1 and OP2.

The routing table corresponding to figure 3 is shown in figure 4. A consequence of splitting the audio sources 14 is that more than one audio input port 13 can correspond to the same audio source 14 (for example channels 1 and 6 both receive audio from the same audio source, presl).

Shown in figure 5 is an alternative embodiment of a distributed audio signal processing apparatus 10 according to the invention. This embodiment is similar to that of figures 2 and 3 except that the matrix IS of one signal processing block 11 is connected to the matrix 16 of the other signal processing block 12 by a mixing bus 25. The mixing bus 25 has an important function. A matrix output 18 from one matrix 15 (which may correspond to only one matrix input 17, for example presl}} can be passed to a matrix 16 in another signal processing block 12. This allows audio routes to start in one signal processing block 11 and end in a different signal processing block 12.

As with figure 3 the remote signal processing block 12 is programmed with audio routes which produce a mix of presl, pres2 and venue ambient at OP1 and OP2 for consumption by the presenters. In contrast to the embodiment of figure 3 however further audio routes are programmed which extend from presl, pres2 and venue ambient to main 1 of the signal processing block 11 local to the studio. The consequence of this is that the remote matrix 16 produces the mix for output at OP1 and QP2 but also sends this mix over the mixing bus 25 to the signal processing block 11 local to the studio. The local signal processing block 11 has also been programmed with audio routes which terminate at main 1 (corresponding to misc local 1 and tnisc local 2). The matrix 15 of the local signal processing block 11 therefore mixes the mixed signal it has received over the mixing bus 25 with these additional audio routes and provides the final mix at main 1.

Figure 6 shows the routing table for the embodiment of figure 5. The important distinction between this and figure 4 is that audio routes can begin in one signal processing block 11,12 but end in another 11,12. The consequence of this is that there is now only one control 21 per audio input port 13. This is conceptually much simpler for an operator to manage. An operator need only decide where he would like audio from an audio input port 13corresponding to a particular audio source 14 to end. In the embodiment of figure 5 for example the operator desires the voice from presl to appear both at main 1 and OP1 and so simply includes these outputs in the routing table. The control console 20 programs the signal processing blocks 11.12 with the appropriate audio route. If during broadcast it is desired that the presenter at OP1 can hear the audio source misc local 1 the operator simply adds this to the routing table. The control console 20 programs the local and remote signal processing blocks 11,22 with a new audio route corresponding to this. At a microscopic level this can be achieved in a number of ways. In one (non-limiting example) the control console 20 programs the local matrix IS so that it mixes misc local 1 onto main 1 as before but also places a copy of misc local 1 onto the mixing bus 25 with a target address of OP1. The remote matrix 16 picks up this signal off the mixing bus 25, realises it is going to the same target destination as pres 1, pres 2 and venue ambient and mixes them ail together before providing the final mix at OP1. In an alternative non-limiting example, the mixing bus 25 comprises a plurality of individual paths, in order to create a new audio route the control console 20 programs the local matrix 15 to provide a copy of pres 1 on a path of the mixing bus 25. It also programs the remote matrix 16 to receive the copy of pres 1 from the path of the mixing bus 25 and pass it to OP1 along with matrix inputs 17 for that matrix 16 destined for OP1.

When an audio route spans multiple signal processing blocks 11,12 there is a choice to be made as to where mixing is to be performed. It is preferred that each matrix 15,16 performs local mixing. When a matrix 15,16 requires for one of its matrix outputs 18 matrix inputs 17 from audio input ports 13 in the same signal processing block 11,12 the matrix 15,16 performs the mixing itself rather than passing the matrix inputs 17 corresponding to these audio input ports 13 over the mixing bus 25 to be mixed elsewhere. If there is a signal on the mixing bus 25 also bound for the same matrix output 18 this is also included in the mix by the matrix 15,16. The matrix 15,16 may also provide the mix to the mixing bus 25 if it is required for consumption by a matrix 15,16 elsewhere. This rule of 'soon as possible' mixing has an important technical advantage. With reference to figure 5, presenter 1 would like to hear his own voice and that of presenter 2 (from audio sources pres 1 and pres 2). Because mixing is done at the remote venue by the remote matrix 16 the required mix OP1 is available instantly without any audio lag. In contrast if presl and pres 2 were passed over the bus 15 back to the studio, mixed at the studio and then passed back over the mixing bus 25 to the remote matrix 16 there would be a slight audio delay between the presenter speaking and hearing his own voice in his headset. This can be very off putting for a presenter. Local mixing eliminates this audio delay. A further embodiment of the invention 10 is shown in figure 7. In this embodiment each audio input port 13 is connected to one channel 19 only. Further, the remote and local matrices 16,15 are slaved together. 8y slaving the matrices 15,16 together each matrix output 18 of one matrix 15,16 is mirrored in a corresponding matrix output 18 of the other matrix 15,16 ie the outputs 18 of the two matrices 15,16 are the same. Mixing is still done locally. For example if one required a mix from the two remote presenters this mix is generated in the remote matrix 16. It is provided to an output 18 of the remote matrix 16. The mix is also passed over the mixing bus 25 to the local matrix 15 which outputs it at the corresponding slaved matrix output 18. The operator may require a mix which is a combination of the speech of the local presenters and the remote presenters, in this instance the remote matrix 16 generates a partial mix which is a mix of the speech of the remote presenters and provides this to the mixing bus 25. The local matrix 15 generates a partial mix which is a mix of the speech of the local presenters and again provides it to the mixing bus 25. Each matrix 15,16 then combines its own partial mix with the partial mix received over the bus 25 to produce a final mix which is output to one of its matrix outputs 18. In this way the outputs of the two matrices 15,16 are identical.

For the operator this arrangement has a considerable conceptual advantage. The operator need only consider a single set of audio input ports 13 and matrix outputs 18. The operator can be confident that each required mix is available at a matrix output 18 of every matrix 15,16. Further, since mixing is done locally, for mixes which are sourced from audio input ports 13 of one signal processing block 11,2 the output mix at that block 11,12 will have no network delay. This will happen automatically without the operator having to specifically program audio routes for this to be the case.

Figure 7 also shows output processors 26 connected to the matrix outputs 18. These output processors 26 further process the audio mix from the matrix outputs 18. Preferably these output processors 26 are slaved together such that each output processor 26 which is connected to a mirrored matrix output 18 behaves identically to each other output processor 26 connected to the same mirrored matrix output 18 of other matrices 15,16. The invention has been described with reference to one local distributed signal processing block 11 and one local remote processing block 12. In further alternative embodiments of the invention there may be more distributed signal processing blocks.

Claims

1. A distributed audio signal processing apparatus comprising

at least two programmable signal processing blocks, each signal processing block comprising a routing matrix comprising a plurality of matrix inputs and at least one matrix output, each matrix input having a channel connected thereto; and, a plurality of audio input ports

2. A distributed audio signal processing apparatus as claimed in claim 1 comprising at least one audio route, each audio route extending within one signal processing block.

3. A distributed audio processing apparatus as claimed in claim 1, wherein the matrices are connected together by a mixing bus.

4. A distributed audio signal processing apparatus as claimed in claim 3 comprising at least one audio route, the at least one audio route extending from one signal processing block across the mixing bus to another signal processing block

5. A distributed audio signal processing apparatus as claimed in either of claims 3 or 4 wherein the matrices perform local mixing.

6. A distributed audio processing apparatus as claimed in any one of claims 2 to 5, wherein the matrices are slaved together over the mixing bus such that the outputs for each matrix are the same.

7. A distributed audio signal processing apparatus as claimed in claim 6 wherein each matrix performs a local mix of signals from audio input ports in the same signal processing block as the matrix which are destined for the same matrix output and provides this partial mix to the mixing bus, and if a partial mix is available on the mixing bus for that matrix output it combines it with its own local mix to produce a final mix at the local version of the matrix output.

8. A distributed audio signal processing apparatus as claimed in any one of claims 1 to 7, wherein each matrix output is connected to an output processor for processing the mixed audio output from the matrix output.

9. A distributed audio processing apparatus as claimed in claim 8 wherein the output processor connected to the matrix output of one signal processing block is slaved with the output processor of the corresponding matrix output of the other signal block such that the two output processors process the mixed audio signals they receive identically.

10. A distributed audio signal processing apparatus as claimed in any one of claims 1 to 9, wherein the interface further displays the channels of the signal processing blocks, the created audio route including the channel selected in the interface.

11. A distributed audio signal processing apparatus as claimed in any one of claims 1 to 9, wherein the control console automatically determines the channel to include in the audio route.

12. A distributed audio signal processing apparatus as claimed in any one of claims 1 to 9, further comprising an audio source connected to an audio input port.

13. A distributed audio signal processing apparatus substantially as hereinbefore described.