Methods and systems for switching between multiple earbud architectures

Abstract

In this disclosure, a method (50) is proposed for switching from a first Bluetooth audio source (20) to a second Bluetooth audio source (21) in a user-friendly manner, for example, reducing latency. This method is performed by an audio rendering system (10), which includes a primary wireless speaker (11) and a secondary wireless speaker (12). The audio rendering system receives a first audio stream from the first audio source using a first audio topology, the first audio topology including a first set of wireless links. Upon receiving a request to switch to a second audio stream using the second audio topology (51), (52) a second set of wireless links is established, and reception of the second audio stream (53) begins, while (54) the audio rendering system and the first audio source are maintained connected via the first set of wireless links. The wireless speaker can be a wireless earbud, bookshelf speaker, floorstanding speaker, outdoor speaker, subwoofer, or headphone speaker.

Description

Technical Field

[0001] This disclosure relates to a method for switching between a first audio source and a second audio source using an audio rendering system comprising a main wireless speaker and at least one secondary wireless speaker when a first audio source uses a first audio topology and a second audio source uses a second audio topology different from the first audio topology. Background Technology

[0002] Most current Bluetooth audio rendering systems use a single acknowledged Bluetooth audio stream with an associated audio source. In fact, the Bluetooth protocol, and especially the Advanced Audio Distribution Profile (A2DP), which defines how audio streams are sent over a Bluetooth link, is limited to supporting only a single point-to-point communication between the audio source and the audio rendering system.

[0003] Due to this limitation of the Bluetooth protocol, even truly wireless handsets, which include systems with two separate Bluetooth rendering units in the form of separate earphones, only have a single confirmed Bluetooth audio stream with an audio source such as a smartphone.

[0004] To maintain compatibility with standards, two audio topologies have been developed to allow two Bluetooth headsets to receive audio data.

[0005] The first audio topology is referred to as the forwarding audio topology and includes a first confirmed Bluetooth audio stream with the first Bluetooth headset, and the first Bluetooth headset uses a second confirmed Bluetooth audio stream to relay audio data to the second Bluetooth headset.

[0006] The second audio topology is referred to as the eavesdropping audio topology, and it also includes a first confirmation Bluetooth audio stream with the first Bluetooth headset, and the first headset provides information to the second headset so that the second headset can sniff / eavesdrop on the audio stream transmitted on the wireless link between the audio source and the first headset. However, the second headset never directly confirms the audio source (it usually confirms the first headset, and then the first headset will confirm the audio source).

[0007] None of these audio topologies are optimal. Forwarding audio topologies require the first earpiece to retransmit the audio data, while eavesdropping audio topologies require both earpieces to receive the same stereo audio stream (playing only one of the two audio channels of the stereo audio stream at a time). They require additional bandwidth usage, which reduces stability and increases power consumption.

[0008] Furthermore, the number of audio rendering systems that receive audio streams from a single audio source is limited to these audio topologies.

[0009] Therefore, new audio topologies have been developed to improve performance relative to existing topologies and support new use cases. These new audio topologies include:

[0010] - Dual-stream audio topology, which enables both headphones to obtain a mono audio stream from the same audio source, thereby reducing power consumption;

[0011] - A broadcast audio topology that enables an unlimited number of wireless handsets to obtain the same audio stream from a single audio source.

[0012] These audio topologies are not currently included in the Bluetooth standard and are only available on audio sources that implement these new capabilities as proprietary enhancements.

[0013] Therefore, during the connection establishment process between the audio source and the wireless earpiece, the audio topology is selected by exchanging the corresponding audio topology capabilities. However, the configuration is always static, meaning it will not change until all audio sources are disconnected from the wireless earpiece. Switching between two audio sources is done by disconnecting the first audio source and connecting to the second, which degrades the user experience because it takes longer.

[0014] The new specification for Bluetooth Low Energy (BLE) Audio over Bluetooth aims to introduce these new audio topologies into the Bluetooth standard. However, the same problem will remain because existing Bluetooth audio rendering systems cannot implement it, as it requires hardware modifications.

[0015] Therefore, a solution is needed that facilitates switching from a first audio source to a second audio source in a user-friendly manner, such as reducing latency. This is especially necessary because the introduction of new audio topologies in the BLE standard will increase the number of use cases that may require switching between different audio topologies. Summary of the Invention

[0016] This disclosure aims to provide a solution that overcomes all or some of the limitations discussed above.

[0017] Specifically, this disclosure aims to propose a solution for switching from a first audio source to a second audio source in a user-friendly manner.

[0018] Furthermore, this disclosure aims to provide a solution that, at least in some embodiments, limits the power consumption of the audio rendering system while enabling efficient switching.

[0019] For this purpose, and according to a first aspect, this disclosure relates to a method for switching between a first audio source and a second audio source via an audio rendering system including a primary wireless speaker and at least one secondary wireless speaker, the audio rendering system receiving a first audio stream from the first audio source using a first audio topology, the first audio topology corresponding to a first set of wireless links established between the primary wireless speaker, the secondary wireless speaker, and the first audio source, wherein the method includes the following steps:

[0020] - Receive a request to switch to receiving a second audio stream from a second audio source by using a second audio topology, the second audio topology corresponding to a second set of wireless links between the main wireless speaker, the secondary wireless speaker and the second audio source, the second audio topology being different from the first audio topology;

[0021] -Establish a second set of wireless links for a second audio topology;

[0022] - Start receiving the second audio stream;

[0023] - While receiving the second audio stream, maintain the audio rendering system and the first audio source connected via wireless links in the first set of wireless links.

[0024] The main wireless speaker or secondary wireless speaker can be a wireless earbud, bookshelf speaker, floor speaker, outdoor speaker, subwoofer, or headphone speaker.

[0025] Therefore, according to this disclosure, when switching from a first audio source to a second audio source that requires the use of a second audio topology different from that used with the first audio source, the audio rendering system (e.g., a wireless earpiece or speaker) maintains at least one of the wireless links in a first set of wireless links of the first audio topology while receiving the second audio stream from the second audio source.

[0026] The maintained at least one wireless link is a wireless link between the first audio source and one of the main wireless speaker and the secondary wireless speaker, so that the first audio source and the audio rendering system remain connected, while the audio rendering system receives and plays a second audio stream from the second audio source.

[0027] In this disclosure, a wireless link between two entities means that the respective data link layers of the entities are configured and ready to use the wireless physical layer to exchange protocol data units. The data link layer is the protocol layer directly above the physical layer, and the wireless link can use either a connected or connectionless mode to exchange protocol data units between the entities.

[0028] In this disclosure, maintaining a wireless link involves a connected mode and means that at least signaling data is cyclically exchanged on the wireless link to prevent any termination of the wireless link. Therefore, it is assumed that the first audio topology includes at least one wireless link in connected mode between the first audio source and the audio rendering system, which is maintained when switching from the first audio source to the second audio source.

[0029] Because at least one wireless link is maintained between the audio rendering system and the first audio source, the first audio source is not disconnected from the audio rendering system. Therefore, it is not necessary to stop receiving the first audio stream in advance before starting to receive the second audio stream. Thus, it is possible to switch to playing the second audio stream immediately after or even before stopping the first audio stream, resulting in an enhanced user experience.

[0030] Furthermore, since at least one wireless link is maintained between the audio rendering system and the first audio source when receiving the second audio stream, it will be possible to quickly process switchback requests (i.e., requests to switch back from the second audio source to the first audio source), thereby reducing switchback wait time and enhancing the user experience.

[0031] By cyclically exchanging signaling data on the wireless link, at least one wireless link between the first audio source and the audio rendering system can be maintained continuously, for example, as long as the audio rendering system and the first audio source are within range, and / or for a predetermined duration (e.g., until a predetermined timer expires), etc. This may also depend on, for example, the corresponding type of audio stream. For instance, if the first audio stream corresponds to a music stream and the second audio stream corresponds to a telephone call, the wireless link can be maintained for the entire duration of the telephone call because once the telephone call (the second audio stream) ends, a switchback request is likely to be received, automatically or manually triggered by the user of the audio rendering system. Conversely, if the first audio stream corresponds to a telephone call and the second audio stream corresponds to a music stream, it is possible to maintain the wireless link between the audio rendering system and the first audio source for a predetermined duration, etc.

[0032] In a particular embodiment, the method for switching may further include one or more of the following features, which may be considered individually or in any technically possible combination.

[0033] In a particular embodiment, when the second audio stream is received, only one wireless link in the first set of wireless links is maintained between the main wireless speaker and the first audio source, and any other wireless links in the first set of wireless links are not maintained and can actually be actively terminated.

[0034] In this scenario, power consumption and stability are optimized because bandwidth usage is reduced by maintaining a single wireless link.

[0035] In a particular embodiment, when the second audio stream is received, and when the audio rendering system has previously received the third audio stream from the third audio stream using a third audio topology, the third audio topology includes a third set of wireless links, wherein only one wireless link in the third set of wireless links is maintained between the secondary wireless speaker and the third audio source, and no other wireless links in the third set of wireless links are maintained.

[0036] Therefore, when an audio rendering system is connected to two audio sources (the first and the third audio sources) while receiving audio streams from another audio source (the second audio source), it may be advantageous to use different wireless speakers (between the first and the second wireless speakers) to maintain wireless links to the first and the third audio sources respectively for the purpose of load and power consumption balancing.

[0037] In a particular embodiment, when the second audio stream is received, all wireless links of the first set of wireless links of the first audio topology are maintained.

[0038] In this scenario, power consumption and stability are not optimized, but any switchback request will be processed very quickly because the entire first audio topology will be maintained while the second audio stream is received.

[0039] In a particular embodiment, the method for switching includes:

[0040] - Obtain a second audio configuration for the primary and secondary wireless speakers to be used with the second audio topology, the second audio configuration being different from the first audio configuration used with the first audio topology;

[0041] - Configure the main wireless speaker and the secondary wireless speaker with the second audio configuration before starting to receive the second audio stream.

[0042] For example, the first audio configuration and the second audio configuration include at least one of the following parameters:

[0043] -Character parameters;

[0044] -Synchronization parameters;

[0045] -Audio encoding parameters;

[0046] - Channel mapping parameters.

[0047] In a particular embodiment, the method for switching includes:

[0048] - Receive the request to switch back to receiving the first audio stream from the first audio source;

[0049] -If all wireless links in the first set of wireless links are not maintained, then establish all wireless links in the first set of wireless links for the first audio topology.

[0050] - Begin receiving the first audio stream;

[0051] - While receiving the first audio stream, maintain the audio rendering system connected to the second audio source via the wireless link in the second set of wireless links.

[0052] As discussed above, it is possible to maintain one or more wireless links in the second set of wireless links while receiving the first audio stream. It is also possible to maintain all wireless links in the second set of wireless links while receiving the first audio stream.

[0053] In a particular embodiment, after a switchback request has been received, the first audio topology is retrieved from data stored in the memory of the audio rendering system, or the first audio topology is received from the first audio source via a wireless link maintained between the audio rendering system and the first audio source.

[0054] In a particular embodiment, the first audio topology is one of the following audio topologies:

[0055] -Forward audio topology;

[0056] - Eavesdropping audio topology: and

[0057] - Dual-stream audio topology;

[0058] Furthermore, the second audio topology is a different topology from the following audio topologies:

[0059] -Forward audio topology;

[0060] -Eavesdropping audio topology:

[0061] - Dual-stream audio topology; and

[0062] -Broadcast audio topology.

[0063] In a particular embodiment, the dual-stream audio topology uses two BLE-connected isochronous CIS logic transmissions between the first or second audio source and the primary wireless speaker and the secondary wireless speaker, respectively.

[0064] In a particular embodiment, the broadcast audio topology uses a BLE broadcast isochronous stream BIS logic transmission between a first audio source or a second audio source and a primary wireless speaker and a secondary wireless speaker.

[0065] In a particular embodiment, the method for switching includes, when the first audio topology is a forwarding audio topology and the second audio topology is a dual-stream audio topology, and a first set of wireless links exists in the wireless link between the secondary wireless speaker and the primary wireless speaker and in the wireless link between the first audio source and the primary wireless speaker:

[0066] -Terminate the wireless link between the secondary wireless speaker and the primary wireless speaker; and

[0067] - Change the role parameter of the main wireless speaker from master device to slave device.

[0068] According to a second aspect, this disclosure relates to a computer program product including instructions that, when executed by an audio rendering system including a main wireless speaker and at least one secondary wireless speaker, configure the audio rendering system to perform a switching method according to any embodiment of the present invention, each of the main wireless speaker and the secondary wireless speaker including processing circuitry, a wireless communication unit, and an audio rendering unit.

[0069] According to a third aspect, this disclosure relates to an audio rendering system, the audio rendering system including a main wireless speaker and at least one secondary wireless speaker, each of the main wireless speaker and the secondary wireless speaker including processing circuitry, a wireless communication unit and an audio rendering unit, wherein the audio rendering system is configured to perform a switching method according to any embodiment of the present invention.

[0070] In a particular embodiment, the audio rendering system may further include one or more of the following features, either individually or in any technically possible combination.

[0071] In a particular embodiment, the audio rendering system corresponds to a wireless earpiece.

[0072] In a particular embodiment, the wireless communication unit is a Bluetooth communication unit, preferably a BLE communication unit. Attached Figure Description

[0073] The invention will be better understood by reading the following description, which is given by way of example and is not limiting, and reference is made to the accompanying drawings, which illustrate:

[0074] Figure 1 A schematic diagram illustrating the different audio topologies between the audio rendering system and the audio source;

[0075] Figure 2 : A schematic diagram of an exemplary embodiment of the audio rendering system;

[0076] Figure 3 : A diagram illustrating the main steps of an exemplary embodiment of a method for switching between different audio sources;

[0077] Figure 4 : A diagram illustrating the main steps of another exemplary embodiment of a method for switching between different audio sources;

[0078] Figure 5 and Figure 6 A diagram illustrating the scene switching process;

[0079] Figure 7 The diagram illustrates an exemplary embodiment of switching from a forwarding audio topology to a dual-stream audio topology by an audio rendering system.

[0080] In these figures, the same reference numerals from one figure to another denote the same or similar elements. For clarity, the elements shown are not drawn to scale unless otherwise explicitly stated. Detailed Implementation

[0081] In this disclosure, the audio source can be any device capable of transmitting an audio stream via one or more wireless links. The audio source can be, for example, a smartphone, laptop computer, voice assistant, tablet computer, etc.

[0082] The audio rendering system 10 can be any device capable of receiving audio streams via a wireless link and playing the received audio stream content to make it perceptible to a user. Furthermore, the audio rendering system 10 includes a main wireless speaker 11 and at least one secondary wireless speaker 12. Each of these speakers is "wireless," in the sense that audio data to be played by each wireless speaker is received via a wireless link. Each of the main wireless speaker 11 and the secondary wireless speaker 12 can be, for example, a wireless amplifier, wireless acoustic or bone conduction headphones, a wireless subwoofer, etc.

[0083] This disclosure relates to a method 50 for switching between a first audio source 20 and a second audio source 21 via an audio rendering system 10 when the first audio source 20 and the second audio source 21 use different audio topologies. Each audio topology corresponds to a set of at least one wireless link established between a primary wireless speaker 11, a secondary wireless speaker 12, and audio sources 20 and 21.

[0084] For example, the audio rendering system 10 corresponds to a wireless earpiece, but this disclosure is not limited thereto and can be applied to any type of audio rendering system 10 including a main wireless speaker 11 and at least one secondary wireless speaker 12.

[0085] Figure 1 The illustrations represent non-limiting examples of different audio topologies that may be used in this disclosure.

[0086] Figure 1Part a) illustrates a first audio topology, referred to as the "forwarded audio topology." In the forwarded audio topology, the set of wireless links includes two wireless links. A first wireless link is established between the audio source 20 and the primary wireless speaker 11. A second wireless link is established between the primary wireless speaker 11 and the secondary wireless speaker 12 to allow the primary wireless speaker 11 to forward audio data (e.g., a specific audio channel of a stereo audio stream) to the secondary wireless speaker 12 for playback by said secondary wireless speaker 12. In the forwarded audio topology, no wireless link is established between the audio source 20 and the secondary wireless speaker 12.

[0087] Figure 1 Section b) illustrates the second audio topology, referred to as the "eavesdropping audio topology." In this eavesdropping audio topology, the set of wireless links comprises two wireless links. A first wireless link is established between the audio source 20 and the main wireless speaker 11. A second wireless link is established between the main wireless speaker 11 and the secondary wireless speaker 12 to allow the main wireless speaker 11 to provide information about the first wireless link to the secondary wireless speaker 12, enabling the secondary wireless speaker 12 to sniff / eavesdrop on the audio stream content transmitted on the first wireless link (indicated by the dashed line) without actually connecting to the audio source 20.

[0088] Figure 1 Part c) illustrates a third audio topology, referred to as a "dual-stream audio topology." In this dual-stream audio topology, the set of wireless links comprises two wireless links. A first wireless link is established between audio source 20 and primary wireless speaker 11. A second wireless link is established between audio source 20 and secondary wireless speaker 12. Each of the primary wireless speaker 11 and secondary wireless speaker 12 receives its own audio data (e.g., a specific audio channel of a stereo audio stream) via a separate point-to-point wireless link to audio source 20.

[0089] Figure 1 Part d) illustrates a fourth audio topology, referred to as a "broadcast audio topology." In a broadcast audio topology, the set of wireless links comprises a single wireless link that typically uses a connectionless mode. Therefore, in a broadcast audio topology, the audio source 20 and the audio rendering system 10 do not need to be connected at the data link layer. From the perspective of the audio source 20, only a single data link layer is configured to send Protocol Data Units to both the primary wireless speaker 11 and the secondary wireless speaker 12 via different corresponding wireless paths. Each of the primary wireless speaker 11 and the secondary wireless speaker 12 receives the entire audio stream via a separate wireless path to the audio source 20. Compared to a dual-stream audio topology, the audio source 20 performs only one transmission, which can be received by multiple receivers (not just the primary wireless speaker 11 and the secondary wireless speaker 12) via a separate wireless path in a point-to-multipoint architecture.

[0090] Figure 2 The main components of an exemplary embodiment of the audio rendering system 10 are schematically shown.

[0091] like Figure 2 As shown, the audio rendering system 10 includes a main wireless speaker 11 and at least one secondary wireless speaker 12. For example, each of the main wireless speaker 11 and the secondary wireless speaker 12 can be a wireless amplifier, wireless headphones, a wireless subwoofer, etc.

[0092] Each of the main wireless speaker 11 and the secondary wireless speaker 12 also includes wireless communication units 110 and 120, processing circuits 111 and 121, and audio rendering units 112 and 122.

[0093] Each wireless communication unit 110, 120 is used to establish a wireless link with an audio source and corresponds, for example, to radio frequency circuitry including components known to a person skilled in the art (antenna, amplifier, local oscillator, mixer, analog and / or digital filters, etc.). The wireless communication units 110, 120 implement at least one wireless communication protocol. For example, the wireless communication units 110, 120 may include at least one of the following:

[0094] - Bluetooth communication unit;

[0095] -Ultra-wideband (UWB) communication unit;

[0096] -Wi-Fi communication unit;

[0097] -ZigBee communication unit, etc.

[0098] For example, each processing circuit 111, 121 includes one or more processors and storage devices (magnetic hard disk, solid-state disk, optical disk, electronic storage, etc.), wherein the computer program product is stored in the form of a set of program code instructions that are executed to implement all or part of the steps of method 50 for switching between the first audio source 20 and the second audio source 21. Alternatively, or in combination with thereof, processing circuits 111, 121 may include one or more programmable logic circuits (FPGA, PLD, etc.) and / or one or more application-specific integrated circuits (ASIC), and / or collections of discrete electronic components, etc., adapted to implement all or part of the steps of switching method 50.

[0099] Each audio rendering unit 112, 122 can be any suitable device adapted to make the audio stream audible to the user. Therefore, each audio rendering unit 112, 122 can be, for example, any kind of electroacoustic transducer.

[0100] The processing circuits 111, 121, wireless communication units 110, 120, and audio rendering units 112, 122 of the audio rendering system 10 form a collection of devices configured with software (specific computer program products) and / or hardware (processors, FPGAs, PLDs, ASICs, discrete electronic components, radio frequency circuits, electroacoustic transducers, etc.) to implement the steps of the switching method 50 discussed below.

[0101] In the following description, the wireless communication units 110 and 120 of the audio rendering system 10 are considered as Bluetooth communication units in a non-limiting manner. Therefore, the wireless link established by the audio rendering system 10 and the audio source between the main wireless speaker 11 and the secondary wireless speaker 12 is considered a Bluetooth link.

[0102] In this disclosure, an audio stream corresponds to application-level data representing an audio signal. For example, it can be a bitstream from an audio streaming application, a locally stored music file read by the application, the output of an audio server, etc. Audio stream content corresponds to useful data (corresponding to metadata) representing the audio data actually played by the audio rendering system 10. Audio stream content may include one or more audio channels (e.g., mono or stereo music).

[0103] Bluetooth audio streaming refers to the Bluetooth terminology and specifies the logical communication used for streaming application-level audio content between an audio source and an audio rendering system 10. Bluetooth audio streaming uses Bluetooth packets over a single Bluetooth logical link (multiple Bluetooth audio streams can use the same logical link).

[0104] For example, a dual-stream audio topology can use two Bluetooth audio streams, transmitted between the audio source and the primary wireless speaker 11 and the secondary wireless speaker 12 using corresponding BLE connections and isochronous stream (CIS) logic, respectively. As an example, a broadcast audio topology can use a single Bluetooth audio stream transmitted using a BLE broadcast isochronous stream (BIS) logic between the audio source and the primary wireless speaker 11 and the secondary wireless speaker 12.

[0105] Furthermore, as discussed above, when its corresponding data link layer is configured and ready to exchange protocol data units using connection mode, the audio rendering system 10 is referred to as "connected" to the audio source via a wireless link.

[0106] Furthermore, an audio stream is referred to as "active" when the audio stream content is transmitted through the air from the audio source to the audio rendering system 10, and the audio rendering system 10 processes the received wireless signal to extract the audio stream content transmitted by the audio source. When no audio stream content is transmitted through the air, or when the audio stream content is transmitted through the air but is not extracted by the audio rendering system 10 from the received wireless signal, the audio stream is referred to as "inactive".

[0107] Figure 3 The schematic diagram illustrates the main steps of an exemplary embodiment of a method 50 for switching between a first audio source 20 and a second audio source 21, the steps being performed by an audio rendering system 10.

[0108] like Figure 3 As shown, the switching method 50 includes step 51 of receiving a request to switch to receiving a second audio stream from a second audio source 21 using a second audio topology, the second audio topology including a second set of wireless links between a primary wireless speaker 11, a secondary wireless speaker 12 and the second audio source 21.

[0109] The second audio topology differs from the first audio topology and can be determined based on different parameters.

[0110] For example, in some embodiments, the second audio topology may be determined based on the audio source capabilities of the second audio source 21. In this case, when a first wireless link is established between the audio rendering system 10 and the second audio source 21, the second audio source 21 may provide a list of supported audio topologies. This list may be stored in the memory of the audio rendering system 10 for later use. When a request to switch to the second audio source 21 is received, the list may be retrieved, and the second audio topology may be selected from the supported audio topologies. According to another example, the second audio source 21 may explicitly request that a specific audio topology be used as the second audio topology.

[0111] According to yet another example, in some embodiments, the second audio topology can be determined based on audio streaming capabilities. In practice, the second audio stream may need to use a specific audio topology. In this case, when a request to switch to the second audio source 21 is received, the audio rendering system 10 can determine that the second audio stream requires a specific audio topology and therefore select that specific audio topology as the second audio topology.

[0112] Based on the above discussion, it is understood that when a first wireless link is established between the second audio source 21 and the audio rendering system 10 (e.g., by reading the audio source capability of the second audio source 21), when a new audio stream is detected to be available (e.g., in a new audio stream indication broadcast message or unicast request), etc., the second audio topology can be determined.

[0113] Furthermore, it is emphasized that the switching request can be triggered by the second audio source 21 or the first audio source 20, or by the user, or by the audio rendering system 10 automatically, based on the corresponding priority of the audio streams available from different audio sources connected to the audio rendering system 10, and so on.

[0114] Once the audio rendering system 10 has received the switching request, the switching method 50 includes step 52 of establishing all wireless links of a second set of wireless links for the second audio topology so that the second audio stream can be received using the second audio topology.

[0115] It should be noted that in some cases, switching from the first audio topology to the second audio topology may require not only establishing a new set of wireless links, but also changing the audio configurations of the primary wireless speaker 11 and the secondary wireless speaker 12. The audio configurations of the primary wireless speaker 11 and the secondary wireless speaker 12 correspond to parameter values ​​that affect the behavior of the audio rendering system 10 on the established wireless links. For example, the first audio configuration and the second audio configuration (associated with the first audio topology and the second audio topology, respectively) include at least one of the following parameters:

[0116] -Character parameters;

[0117] -Synchronization parameters;

[0118] -Audio encoding parameters;

[0119] - Channel mapping parameters, etc.

[0120] For each wireless link established by the audio rendering system 10, a role parameter indicates whether the primary wireless speaker 11 or the secondary wireless speaker 12 acts as a "master device" or a "slave device" on that wireless link. For example, in a forwarding audio topology, the primary wireless speaker 11 involved in two wireless links of a set of wireless links can act as a "master device" on both wireless links. Conversely, the secondary wireless speaker 12 can act as a "slave device" on the single wireless link it is involved in. In a dual-stream audio topology, both the primary wireless speaker 11 and the secondary wireless speaker 12 can act as "slave devices" on the wireless link with the audio source, etc.

[0121] Synchronization parameters indicate how the audio data played by the primary wireless speaker 11 and the secondary wireless speaker 12 are synchronized in time. For example, in a forwarded audio topology, the primary wireless speaker 11 can first evaluate the stream clock value, then convert it into a local clock value synchronized between the primary and secondary wireless speakers 11 and 12, and use it to timestamp the audio data forwarded to the secondary wireless speaker 12. In a dual-stream audio topology, the audio source can directly use the Bluetooth clock to timestamp the audio data, thus eliminating the need for conversion to a local clock value.

[0122] Audio encoding parameters indicate which type of audio codec is used. For example, a dual-stream audio topology can use a higher bitrate audio codec, perhaps because each of the primary wireless speaker 11 and the secondary wireless speaker 12 only receives one audio channel from the two audio channels of the stereo audio stream. Conversely, a forwarding audio topology can use a lower bitrate audio codec. The type of audio codec used may also depend on the capabilities of the audio source.

[0123] Channel mapping parameters indicate how audio channels are mapped. For example, in a forwarding audio topology, the primary wireless speaker 11 receives both audio channels of a stereo audio stream, plays only its own audio channel, and forwards the other audio channel to the secondary wireless speaker 12. In a dual-stream audio topology, each of the primary wireless speaker 11 and the secondary wireless speaker 12 receives only a mono audio stream corresponding to its own audio channel of the stereo audio stream. In a broadcast audio topology, each of the primary wireless speaker 11 and the secondary wireless speaker 12 receives a stereo audio stream but plays only its own audio channel from the stereo audio stream.

[0124] Of course, other parameters can be included in the audio configuration, either in combination with or as a substitute for the parameters mentioned above.

[0125] Therefore, switching from the first audio source 20 to the second audio source 21 may also require switching from the first audio configuration to the second audio configuration. If necessary, the switching method 50 may include additional optional steps:

[0126] - Obtain a second audio configuration for the main wireless speaker 11 and the secondary wireless speaker 12 to be used with the second audio topology;

[0127] - Before starting to receive the second audio stream, configure the main wireless speaker 11 and the secondary wireless speaker 12 with the second audio configuration.

[0128] Once the second audio topology is operational, the switching method 50 includes step 53 of starting to receive the second audio stream so that the second audio stream can be played by the audio rendering system 10.

[0129] When the audio rendering system 10 receives a second audio stream from the second audio source 21, the switching method 50 includes step 54 of maintaining at least one wireless link in a first set of wireless links, such that the audio rendering system 10 and the first audio source 20 remain connected.

[0130] In some embodiments, only a single wireless link may be maintained between the first audio source and one of the primary wireless speaker 11 and the secondary wireless speaker 12. In other embodiments, more than one wireless link may be maintained, including maintaining all wireless links in the first set, allowing the first audio topology to coexist with the second audio topology. Furthermore, the number of maintained wireless links may change over time. For example, all wireless links in the first set may be maintained initially for a predetermined duration, and then some of the wireless links may be terminated until only one wireless link in the first set is maintained between the first audio source 20 and the audio rendering system 10, and so on.

[0131] Because the first audio topology is at least partially maintained, the first audio stream can remain active for a longer period than existing solutions, thus enhancing the user experience. Furthermore, any switchback request to receive the audio stream from the first audio source will be received and processed much faster than existing solutions.

[0132] Figure 4 The main steps of an exemplary embodiment of the switching method 50 are schematically illustrated. For example... Figure 4 As shown, the switching method 50 includes Figure 3 All the steps shown.

[0133] At some point after receiving the second audio stream from the second audio source 21 has begun, the switching method 50 includes step 55, whereby the audio rendering system 10 receives a request to switch back to receiving the first audio stream from the first audio source 20. As discussed above with respect to the switching request (step 51), the switchback request can be triggered by either the second audio source 21 or the first audio source 20, or manually by the user, for example, automatically triggered by the audio rendering system 10 based on the corresponding priority of the audio streams available from different audio sources connected to the audio rendering system 10, and so on.

[0134] As discussed above, at least one wireless link of the first set of wireless links of the first audio topology is maintained. If all wireless links of the first set of wireless links have been maintained, it is not necessary to re-establish the wireless links of the first audio topology. If not all wireless links of the first set of wireless links have been maintained, the switching method 50 includes step 56 of establishing all wireless links of the first set of wireless links of the first audio topology, during which unmaintained wireless links of the first set of wireless links are re-established.

[0135] It should be noted that the first audio topology, defined by the first set of wireless links, can be stored in the memory of the audio rendering system 10. Therefore, when a switchback request is received, the first audio topology is quickly determined by retrieving it from said memory. Alternatively, the first audio topology can also be received from the first audio source 20 via the wireless link maintained between the audio rendering system 10 and the first audio source 20. In fact, this information can also be quickly retrieved since a wireless link with the first audio source 20 has already been maintained.

[0136] As previously mentioned, in order for the first audio topology to be operational, it may also be necessary to change the audio configurations of the main speaker 11 and the secondary wireless speaker 12. Preferably, the first audio configuration used with the first audio source 20 before switching to the second audio source 21 is stored in the memory of the audio rendering system 10. In this case, the first audio configuration can be retrieved from the memory for faster configuration of the main speaker 11 and the secondary wireless speaker 12. Alternatively, the first audio configuration may also be received from the first audio source 20 via a wireless link maintained between the audio rendering system 10 and the first audio source 20.

[0137] Once the first audio topology is operational, the switching method 50 includes step 57 of starting to receive the first audio stream from the first audio source 20, i.e., the first audio stream (re-) becomes active.

[0138] Preferably, the switching method 50 includes an optional step 58 of maintaining the audio rendering system 10 connected to the second audio source 21 via at least one wireless link in the second set of wireless links while receiving the first audio stream. All previously described aspects related to maintaining at least one wireless link in the first set of wireless links also apply here. In particular, all wireless links in the second set of wireless links of the second audio topology may be maintained to enable a faster switchback to the second audio source 21 upon request.

[0139] This disclosure relates to any switching from a first audio topology to a second audio topology different from the first audio topology. However, the following use cases are of particular interest:

[0140] - The first audio topology is a forwarding audio topology, and the second audio topology is a dual-stream audio topology or a broadcast audio topology;

[0141] - The first audio topology is an eavesdropping audio topology, and the second audio topology is a dual-stream audio topology or a broadcast audio topology.

[0142] Figure 5 This schematically illustrates the switching from a forwarding audio topology to a dual-stream audio topology.

[0143] exist Figure 5In part a), the audio rendering system 10 (wireless handset) receives a first audio stream from a first audio source 20 (laptop computer) using a forwarding audio topology. Using the forwarding audio topology, the first audio source 20 is connected to a main wireless speaker 11 via a first wireless link, and the main wireless speaker 11 is connected to a secondary wireless speaker 12 via a second wireless link.

[0144] exist Figure 5 In part b), the audio rendering system 10 switches to receiving a second audio stream from a second audio source 21 (smartphone) using a dual-stream audio topology. With the dual-stream audio topology, the first audio source 20 is connected to the main wireless speaker 11 via a first wireless link and to the secondary wireless speaker 12 via a second wireless link. Figure 5 As shown in part b), when the audio rendering system 10 receives the second audio stream, it maintains the wireless link (represented by dashed lines) for forwarding the audio topology.

[0145] Figure 6 This schematically illustrates the switching from a two-stream audio topology to a broadcast audio topology.

[0146] exist Figure 6 In part a), the audio rendering system 10 (wireless earpiece) receives a first audio stream from a first audio source 20 (smartphone) using a dual-stream audio topology. Using the dual-stream audio topology, the first audio source 20 is connected to a primary wireless speaker 11 via a first wireless link and to a secondary wireless speaker 12 via a second wireless link.

[0147] exist Figure 6 In part b), the audio rendering system 10 switches to receiving a second audio stream from a second audio source 21 (alarm, such as a fire alarm) using a broadcast audio topology. Figure 6 As shown in part b), when the audio rendering system 10 receives the second audio stream, it maintains the wireless link of the dual-stream audio topology (represented by dashed lines).

[0148] Figure 7 The exemplary embodiment illustrates how the switching method 50 can be implemented when switching from a forwarding audio topology (laptop) with a first audio source to a dual-stream audio topology (smartphone) with a second audio source 21.

[0149] Initially, the first audio stream from the first audio source 20 is active, causing the first audio stream content to be transmitted by the first audio source 20 and received by the audio rendering system 10 (wireless earpiece) (refer to S70). Then, the second audio source 21 establishes a wireless link with the main wireless speaker 11 (refer to S71) and receives a switching request instructing the audio rendering system 10 to switch to the second audio source 21 (refer to S72). In the example shown, based on the received switching request, the audio rendering system 10 requests the first audio source 20 to stop transmitting the first audio stream (refer to S73), causing the first audio stream to become inactive. Then, the audio rendering system 10 determines the second audio topology (refer to S74), for example, based on the audio source capabilities of the second audio source 21 previously stored by the audio rendering system 10 and / or received from the second audio source 21, or based on the audio stream capabilities of the second audio stream, etc. Then, the audio rendering system 10 terminates the wireless link for forwarding the audio topology between the secondary wireless speaker 12 and the main wireless speaker 11 (refer to S75). Furthermore, the audio rendering system 10 and the first audio source 20 change the role of the main wireless speaker 11 on the wireless link of the forwarding audio topology between the first audio source 20 and the main wireless speaker 11. The role of the main wireless speaker 11 changes from "master device" to "slave device," and the wireless link of the forwarding audio topology between the first audio source 20 and the main wireless speaker 11 is maintained (see S76). Then, the audio rendering system 10 establishes a set of wireless links for the dual-stream audio topology with the second audio source 21. Since the main wireless speaker 11 is already connected to the second audio source 21 via a wireless link, only the wireless link between the second audio source 21 and the secondary wireless speaker 12 is established (see S77). Then, the audio rendering system 10 configures the main wireless speaker 11 and the secondary wireless speaker 12 with the audio configuration to be used with the dual-stream audio topology (see S78). Finally, the second audio stream is enabled, such that the content of the second audio stream is transmitted by the second audio source 21 and processed by the audio rendering system 10 (see S79), while the first audio source 20 and the main wireless speaker 11 remain connected via the wireless link of the forwarding audio topology.

[0150] It should be noted that Figure 7 The order of operations shown is exemplary, and other orders are also possible. For example, in Figure 7 In this context, upon receiving a switching request, the first audio stream is immediately deactivated. However, the first audio stream can also be deactivated later, and even after the second audio stream is enabled (especially if the first audio topology is fully maintained and coexists with the second audio topology).

[0151] It should be noted that in some embodiments, there can be at most one active audio stream. In this case, using a "disconnect-then-connect" approach, the first audio stream needs to be deactivated before the second audio stream is enabled. Therefore, the audio rendering system 10 stops receiving the first audio stream before it begins receiving the second audio stream. This approach is advantageous because it reduces power consumption and processing power of the audio rendering system 10.

[0152] It should be noted that, in this disclosure, stopping the reception of audio streams means that the audio rendering system stops extracting audio stream content from the wireless signals received from the audio source. This may mean exchanging signaling between the audio source and the audio rendering system 10 using a connected wireless link to ensure that the audio source stops transmitting audio stream content to the audio rendering system 10. For example, the audio rendering system 10 can stop receiving audio stream content by sending an Audio / Video Distribution Transport Protocol (AVDTP) pause request to the audio source, and in response, the audio source pauses the Bluetooth audio stream, thus stopping the transmission of (application-level) audio stream content. When considering a broadcast audio topology, the audio source does not stop transmitting audio stream content, but the audio rendering system 10 only needs to stop processing wireless signals to extract the audio stream content broadcast by the audio source.

[0153] Furthermore, initiating audio stream reception signifies that the audio rendering system begins extracting audio stream content from the wireless signals received from the audio source. This could, of course, mean exchanging signaling between the audio source and audio rendering system 10 using a connected wireless link to ensure the audio source begins transmitting audio stream content to audio rendering system 10. For example, audio rendering system 10 can begin receiving audio stream content by sending an AVDTP start request to the audio source (in response, the audio source starts the Bluetooth audio stream and begins transmitting application-level audio stream content) and by starting to extract audio stream content from the received wireless signals. When considering a broadcast audio topology, the audio source's transmission of audio stream content is already underway, so audio rendering system 10 only needs to begin processing the wireless signals to extract the audio stream content broadcast by the audio source.

[0154] In other embodiments, it is possible for at least two (or more) audio streams to be active simultaneously, at least temporarily. In this case, only one audio stream may be played at a time. Therefore, the audio rendering system 10 stops playing the first audio stream before the audio rendering units 112, 122 begin playing the second audio stream. The first audio stream content still received and extracted by the audio rendering system 10 is discarded, for example, and is not played by the audio rendering units 112, 122. However, in other embodiments, it is also possible for the first and second audio streams to be played simultaneously, at least temporarily, for example, by using the second audio stream content to bypass the first audio stream content.

[0155] It should be emphasized that the present invention is not limited to the exemplary embodiments described above. Variations of the exemplary embodiments described above are also within the scope of the present invention.

[0156] For example, an exemplary embodiment has been described by focusing on the fact that the wireless link is a Bluetooth link. However, in other embodiments, other wireless communication protocols may also be used. In some embodiments, the audio rendering system 10 may even support multiple wireless communication protocols and may use different wireless communication protocols to wirelessly connect to different devices.

Claims

1. A method (50) for switching between a first audio source (20) and a second audio source (21) via an audio rendering system (10), the audio rendering system (10) comprising a primary wireless speaker (11) and at least one secondary wireless speaker (12), the audio rendering system (10) receiving a first audio stream from the first audio source (20) using a first audio topology, the first audio topology corresponding to a first set of wireless links established between the primary wireless speaker (11), the secondary wireless speaker (12), and the first audio source (20), wherein, The method (50) includes: The system receives a request to switch to receiving a second audio stream from the second audio source (21) using a second audio topology, the second audio topology corresponding to a second set of wireless links between the main wireless speaker (11), the secondary wireless speaker (12) and the second audio source (21), the second audio topology being different from the first audio topology; Establish a second set of wireless links for the second audio topology; Start receiving the second audio stream; Maintain the connection between the audio rendering system (10) and the first audio source (20) via a wireless link in the first set of wireless links, while receiving the second audio stream.

2. The method (50) according to claim 1, wherein, When the second audio stream is received, only one wireless link in the first set of wireless links is maintained between the main wireless speaker (11) and the first audio source (20), and no other wireless link in the first set of wireless links is maintained.

3. The method (50) according to claim 2, wherein, When the second audio stream is received, and when the audio rendering system (10) has previously received the third audio stream from the third audio source using the third audio topology, the third audio topology corresponds to the third set of wireless links, maintaining only one wireless link in the third set of wireless links between the secondary wireless speaker (12) and the third audio source, and not maintaining any other wireless links in the third set of wireless links.

4. The method (50) according to claim 1, wherein, When the second audio stream is received, all wireless links in the first set of wireless links of the first audio topology are maintained.

5. The method (50) according to any one of claims 1 to 4, comprising: - Obtain a second audio configuration for the primary wireless speaker (11) and the secondary wireless speaker (12) to be used with the second audio topology, the second audio configuration being different from the first audio configuration used with the first audio topology; - Before receiving the second audio stream, the main wireless speaker (11) and the secondary wireless speaker (12) are configured with the second audio configuration.

6. The method (50) according to claim 5, wherein, The first audio configuration and the second audio configuration include at least one of the following parameters: - Character parameters; - Synchronization parameters; - Audio encoding parameters; - Channel mapping parameters.

7. The method (50) according to any one of claims 1 to 4, comprising: Receive a request to switch back to receiving the first audio stream from the first audio source (20); If not all wireless links in the first set of wireless links have been maintained: all wireless links in the first set of wireless links that established the first audio topology; Start receiving the first audio stream; Maintain the connection between the audio rendering system (10) and the second audio source (21) via a wireless link in the second set of wireless links, while receiving the first audio stream.

8. The method (50) according to claim 7, wherein, After receiving a switchback request, the first audio topology is retrieved from data stored in the memory of the audio rendering system (10), or the first audio topology is received from the first audio source (20) via the wireless link maintained between the audio rendering system (10) and the first audio source (20).

9. The method (50) according to any one of claims 1 to 4, wherein, The first audio topology is one of the following audio topologies: -Forward audio topology; - Eavesdropping audio topology; and - Dual-stream audio topology; Furthermore, the second audio topology is a different topology from the following audio topologies: -Forward audio topology; - Eavesdropping audio topology; - Dual-stream audio topology; and -Broadcast audio topology.

10. The method (50) according to claim 9, wherein: - The dual-stream audio topology uses isochronous stream logic with two Bluetooth Low Energy connections for transmission between the first audio source (20) or the second audio source (21) and the main wireless speaker and the secondary wireless speaker, respectively; and / or The broadcast audio topology uses a Bluetooth Low Energy Broadcast isochronous stream logic to transmit between the first audio source (20) or the second audio source (21) and the main wireless speaker (11) and the secondary wireless speaker (12).

11. The method (50) according to any one of claims 1 to 4, comprising: when the first audio topology is a forwarding audio topology and the second audio topology is a dual-stream audio topology, and the first set of wireless links exists in the wireless link between the secondary wireless speaker (12) and the primary wireless speaker (11) and in the wireless link between the first audio source (20) and the primary wireless speaker (11): -Terminate the wireless link between the secondary wireless speaker (12) and the primary wireless speaker (11); and - Change the role parameter of the main wireless speaker (11) from master device to slave device.

12. A computer program product comprising instructions which, when executed by an audio rendering system (10) comprising a primary wireless speaker (11) and at least one secondary wireless speaker (12), configure the audio rendering system (10) to perform the method according to any one of claims 1 to 11, each of the primary wireless speaker (11) and the secondary wireless speaker (12) comprising processing circuitry (111, 121), a wireless communication unit (110, 120), and an audio rendering unit (112, 122).

13. An audio rendering system (10) comprising a primary wireless speaker (11) and at least one secondary wireless speaker (12), each of the primary wireless speaker (11) and the secondary wireless speaker (12) comprising processing circuitry (111, 121), a wireless communication unit (110, 120) and an audio rendering unit (112, 122), wherein the audio rendering system (10) is configured to perform the method according to any one of claims 1 to 11.

14. The audio rendering system (10) according to claim 13, wherein, The audio rendering system (10) corresponds to a wireless earpiece.

15. The audio rendering system (10) according to claim 13 or 14, wherein, The wireless communication units (110, 120) are Bluetooth communication units.

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