Switching device and switching method thereof

Abstract

The present application discloses a switching device and a switching method thereof. The switching device includes a plurality of USB interfaces, an output interface coupled to a playing device, and a controller. Each of the USB interfaces is coupled to an audio / video source device including a description information. The controller is coupled between the plurality of USB interfaces and the output interface. The controller obtains an intersection description information according to the description information of the audio / video source devices. The controller establishes a first communication link between the intersection description information and the playing device. In another embodiment, the present application provides a switching method using the aforementioned switching device. When the switching device switches to select one of the audio / video source devices, as long as the description information of the selected audio / video source device is within the intersection description information, the playing device continues to communicate with the selected audio / video source device through the first communication link, avoiding the time consumed by reestablishing the communication link, and achieving the purpose of fast switching.

Description

TECHNICAL FIELD

[0001] The present application relates to a switching technique, and in particular, to a switching device and a switching method thereof. BACKGROUND

[0002] In recent years, multimedia video technology has developed quite rapidly, especially the promotion of USB transmission protocol, which enables the USB interface to have the ability of high-speed signal transmission, so that the USB interface can be applied to multimedia devices that require high-speed transmission as a medium for video transmission. Among them, the most common are USB video class (UVC) or USB audio class (UAC), wherein the USB video class (such as webcam, digital camera, analog video converter, TV card or still image camera) is a USB transmission protocol that can be plug-and-play without installing any driver program, and through the universal data interface of such USB video class, there are various ways to achieve digital audio data transmission. Therefore, different developers can define any control method, transmission mode, audio format and other parameters according to their own preferences and needs.

[0003] In the prior art, for example Figure 1 As shown in FIG. 1, which is a schematic diagram of a conventional audio-video switching device. The multimedia switching device 10 has a plurality of USB interfaces 11 and an output interface 13. Each USB interface 11 is electrically connected to a plurality of audio-video source devices 12 supporting UVC / UAC specification, and the output interface 13 is used to be electrically connected to a playing device 14. The multimedia switching device 10 can generate a switching signal to select one of the audio-video source devices 12 and the playing device 14 to be electrically connected, so that the selected audio-video source device 12 outputs multimedia streaming signal to the playing device 14.

[0004] In the use architecture of Figure 1 When the user uses the multimedia switching device 10 to select another audio-video source device 12 and the playing device to be electrically connected, the communication between the original audio-video source device 12 and the switching device 10 needs to be disconnected first, and then the newly selected audio-video source device 12 and the playing device 14 need to be re-enumerated, so that the newly selected audio-video source device 12 can transmit multimedia streaming information to the playing device 14 through the re-enumerated channel to achieve the purpose of switching. SUMMARY

[0005] The present application provides a switching device and a switching method for selecting a multimedia source device with UAC / UVC specification connected to the switching device, so that the selected multimedia source device outputs multimedia stream signal to a playing device connected to the switching device. The switching device forms an intersection description information from the intersection of the description information output by each multimedia source device. When the description information of the selected multimedia source device is in the intersection description information, the playing device continues to use the communication connection between the playing device and the switching device before switching, so as to save the time required for re-listing when switching the multimedia source device. In addition, since re-listing is not required, the user can reduce the procedure of resetting the playing device, thereby improving the switching speed.

[0006] In one embodiment, the present application provides a switching device, which comprises a plurality of USB interfaces, an output interface coupled to a playing device, and a controller. Each USB interface is coupled to a multimedia source device comprising description information. The controller is coupled between the plurality of USB interfaces and the output interface. The controller forms an intersection description information from the intersection of at least two of the description information. The controller establishes a first communication link with the playing device via the intersection description information.

[0007] In another embodiment, when the description information of the selected multimedia source device is in the intersection description information, the playing device continues to communicate with the selected multimedia source device via the first communication link. When the description information of the selected multimedia source device is not in the intersection description information, the playing device establishes a second communication link with the selected multimedia source device via the description information of the selected multimedia source device.

[0008] In another embodiment, the present application provides a switching method suitable for a switching device, which comprises recording, by a controller, the description information output by each multimedia source device, forming, by the controller, an intersection description information from the intersection of at least two of the description information, and establishing, by the controller, a first communication link with the playing device via the intersection description information. BRIEF DESCRIPTION OF DRAWINGS

[0009] The accompanying drawings, which are included to provide a further understanding of the present application and are incorporated in and constitute a part of this application, illustrate embodiments of the present application and together with the description serve to explain the present application. In the drawings:

[0010] Figure 1 A schematic diagram of a conventional multimedia switching device.

[0011] Figure 2 A schematic diagram of an embodiment of the switching device of the present application.

[0012] Figure 3An embodiment of the present application for establishing intersection description information.

[0013] Figure 4 An embodiment of the present application for a controller.

[0014] Figure 5 An embodiment of the present application for a switching method.

[0015] Figure 6 Another embodiment of the present application for a switching device.

[0016] Figures 7A-7B Another embodiment of the present application for a switching method. DETAILED DESCRIPTION

[0017] Various exemplary embodiments will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all, exemplary embodiments are shown. The present application may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present application to those skilled in the art. Like numbers refer to like elements throughout. The audio conversion device and its multimedia control device will be described below in various embodiments in conjunction with the drawings, however, the following embodiments are not intended to limit the present application.

[0018] Referring to Figure 2 An embodiment of the present application for a switching device is shown in FIG. 1. In this embodiment, the switching device 2 includes a plurality of USB interfaces 20, an output interface 21, and a controller 22. Each USB interface 20 is connected to an audio / video source device 30a-30d, each of which transmits audio and / or video to the controller 22 of the switching device 2 by USB communication protocol. In one embodiment, each USB interface 20 is connected to a USB hub unit 23 inside the switching device 2, which is in turn connected to a USB host controller 24 and the controller 22. The USB hub unit 23 and the USB host controller 24 can be separate elements or integrated into a single element.

[0019] In this embodiment, the audio / video source devices 30a-30d are USB devices that support UVC or UAC communication protocol, such as webcams, digital cameras, analog video converters, TV cards, and still image cameras. In this embodiment, the USB interfaces 20 can be selected as type A, type B, type C, or a combination of any two or more of the above.

[0020] Each of the video / audio source devices 30a-30d includes descriptor information, the content of which can vary depending on the type of video / audio source device 30a-30d. For example, if the video / audio source device 30a-30d is a UVC webcam or other image device, the descriptor information includes resolution and / or encoding method. In another example, if the video / audio source device 30a-30d is a UAC sound capture device, the descriptor information is channel number and / or sampling rate. In this case, the video / audio source device 30a-30d can transmit to the USB hub unit 23 via the USB interface 20, and the USB host unit 24 receives the descriptor information and the video / audio information output by the video / audio source device 30a-30d.

[0021] The controller 22 is connected to the USB host unit 24, and when the controller 22 performs the enumeration procedure, it receives the descriptor information of each of the video / audio source devices 30a-30d output by the USB host unit 24 to identify the device type of each of the video / audio source devices 30a-30d. In addition, the controller 22 further performs intersection calculation based on the received descriptor information, and obtains the intersection of at least two of the descriptor information of the video / audio source devices 30a-30d to form intersection descriptor information. In one embodiment, the intersection descriptor information can be stored in a storage unit (not shown) in the switching device 2, which can be a random access memory (RAM), such as DRAM or SRAM, or a non-erasable read-only memory (ROM), etc., without being limited thereto. In one embodiment, the intersection descriptor information records which connection ports each of the video / audio source devices 30a-30d corresponds to, for example: Figure 2 The different USB interfaces 20 are shown, and thus the controller 22 can immediately know whether the descriptor information of the video / audio source device corresponding to the USB connection port to which the switching signal generated when switching in the switching device 2 corresponds has been covered by the intersection descriptor information.

[0022] Please refer to Figure 3 which is a schematic diagram of one embodiment of establishing intersection descriptor information. In Figure 3In the present embodiment, the four video / audio source devices 30a-30d are taken as an example of a camera. In the present embodiment, each of the video / audio source devices 30a-30d has resolution as the descriptive element information. For example, the video / audio source device 30a has three resolution information of 3840x 2160 60p, 3840x2160 30p and 1920x1080 60p in the descriptive element information; the video / audio source device 30b has three resolution information of 1920x1080 60p, 1920x1080 30p and 1280x720 60p in the descriptive element information; the video / audio source device 30c has three resolution information of 3840x 2160 30p, 1920x1080 60p and 1280x720 60p in the descriptive element information; and the video / audio source device 30d has three resolution information of 1280x720 60p, 4096x 2160 30p and 1920x1080 60p in the descriptive element information. After the controller 22 receives the descriptive element information of each of the video / audio source devices 30a-30d, the controller 22 further performs intersection calculation to find the resolution commonly possessed by the descriptive element information of the four video / audio source devices 30a-30d. For example, in the present embodiment, the common descriptive element information is 1920x1080 60p, and thus the controller 22 takes 1920x1080 60p as the intersection descriptive information.

[0023] Returning to FIG. 1, Figure 2 As shown in FIG. 2, the controller 22 establishes a first communication link with the playback device 31 via the intersection descriptive information. In an embodiment, the intersection descriptive information generated by the controller 22 is received by the virtual unit 25 to establish a virtual device regarding the video / audio source devices 30a-30d according to the intersection descriptive information. Then the intersection descriptive information is output to the playback device 31 so that the playback device 31 can identify the virtual device via the intersection descriptive information. In the present embodiment, the virtual device takes the intersection descriptive information as its own descriptive element information. The first communication link is the enumeration communication between the controller 22 and the playback device 31 after the controller 22 connects with the playback device 31 via the output interface 21 and the virtual unit 25. The playback device 31 also has a USB host control unit, and thus the virtual device can be enumerated as a USB device conforming to UVC or UAC by the intersection descriptive information. It is to be noted that the output interface 21 can be selected as a type A, a type B, a type C or a combination of any two or more of the aforementioned USB output interfaces.

[0024] In this embodiment, the virtual unit 25 and the controller 22 are two separate elements, but in another embodiment, the virtual unit 25 can be integrated into the controller 22. The virtual unit 25 can be a physical circuit element or in the form of firmware. In one embodiment, the playback device 31 is not limited to a display, a computer, a cloud server, etc., as long as it can convert the multimedia signals generated by the audio / video source devices 30a-30d into sound and images.

[0025] Figure 4 Figure 1 shows a schematic diagram of an embodiment of the controller of the present application. Please refer to Figure 4 In this embodiment, the controller 22 further has a multiplexer 220, an enumeration unit 221, and a switching unit 222. The multiplexer 220 and the enumeration unit 221 are connected to the USB host unit 24. The switching unit 222 is coupled to the multiplexer 220. The multiplexer 220 receives the multimedia signals from the audio / video source devices 30a-30d and selects one of the audio / video source devices 30a-30d according to the switching signal generated by the user operating the switching device 2, so that the multimedia signals of the selected audio / video source device 30a-30d can be output to the playback device 31. It is to be noted that in one embodiment, the multiplexer 220 can simultaneously receive the audio / video information output from the audio / video source devices 30a-30d. In another embodiment, the multiplexer 220 can only receive the audio / video information output from the selected audio / video source device 30a-30d. Regardless of which way is used, it can be determined according to the user's needs and is not limited to a specific way. The enumeration unit 221 receives the description element information of each audio / video source device 30a-30d via the USB host unit 24, finds the common intersection of the description element information of each audio / video source device 30a-30d through an algorithm, and forms the intersection description information to be transmitted to the virtual unit 25. In this embodiment, when the user operates the switching device 2 to switch and select the audio / video source device 30a-30d, the switching unit 222 generates a switching signal to the multiplexer 220 according to the user's selection. The multiplexer 220 couples the playback device 31 to the corresponding one of the audio / video source devices 30a-30d according to the switching signal. When the controller 22 determines that the description element information of the selected audio / video source device 30a-30d is included in the intersection description information according to the switching signal, the playback device 31 continues to communicate with the selected audio / video source device 30a-30d via the first communication link. Otherwise, when the controller 22 determines that the description element information of the selected audio / video source device 30a-30d is not included in the intersection description information, the controller 22 establishes a second communication link between the playback device 31 and the selected audio / video source device 30a-30d according to the description element information of the selected audio / video source device 30a-30d, which will be described in detail later.

[0026] Figure 2 shows a schematic diagram of an embodiment of the audio / video source device of the present application. Please refer toFigure 2 , Figure 4 and Figure 5 ,in, Figure 5 This is a schematic flowchart of an embodiment of the switching method of this application. Switching method 4 includes step 40: providing a switching device 2 (such as...) Figure 2 (As shown). Next, a plurality of audio / video source devices 30a-30d supporting UAC, UVC, or a combination of both are connected to a plurality of USB interfaces 20 on the switching device 2 (step 41). Here, after the switching device 2 detects the plurality of audio / video source devices 30a-30d, the controller 22 of the switching device 2 records a descriptive metadata output from each audio / video source device 30a-30d (step 42). Then, the controller 22 intersects the descriptive metadata to form intersection descriptive information (step 43). Afterward, the controller 22 establishes a first communication connection with the playback device 31 by simulating a virtual device through the intersection descriptive information (step 44). In one embodiment of this step, the virtual unit 25 in the controller 22 receives the intersection descriptive information generated by the enumeration unit 221, and establishes a first communication connection with the playback device 31 for the virtual device of the audio / video source devices 30a-30d (such as UVC or UAC) based on the intersection descriptive information. Next, the playback device 31 can receive multimedia signals from the selected audio / video source devices 30a-30d for playback (step 45). In one embodiment, the audio / video source devices 30a-30d can receive multimedia signals according to preset values ​​at startup or user settings. During playback, when there is a switching action to select other audio / video source devices 30a-30d, the multiplexer 220 of the controller 22 selects one of the audio / video source devices 30a-30d to couple to the playback device 31 according to the switching signal generated by the switching unit 222, and enables the selected audio / video source device 30a-30d to communicate with the playback device 31 according to the first communication connection (step 46).

[0027] It should be noted that in step 46, since the description metadata of the selected audio / video source devices 30a-30d is included in the intersection description information, the playback device 31 does not need to re-enumerate the newly selected audio / video source devices 30a-30d. Instead, it maintains the virtual device simulated in step 44 corresponding to the first communication connection with the playback device 31 for transmission. In this way, the time spent by the playback device 31 in re-enumerating when switching to other audio / video source devices 30a-30d can be saved, and the user can be less likely to reset the playback device 31, thereby speeding up the switching process.

[0028] It should be noted that the parameters of the multimedia signal output by the selected audio-visual source devices 30a-30d will be determined based on the content of the intersection description information. Figure 3Taking the UVC device as an example, the descriptive metadata of each audio-visual source device contains multiple resolutions. Therefore, the intersection descriptive metadata is 1920x108060p resolution, which is used as the output resolution information of the selected audio-visual source devices 30a-30d.

[0029] In another embodiment, please refer to Figure 6 and Figures 7A-7B As shown, where, Figure 6 This is a schematic diagram of another embodiment of the switching device of this application; Figures 7A-7B This is a schematic diagram of another embodiment of the switching device and switching method of this application. The architecture of the switching device 2 in this embodiment is basically the same as described above. Figure 2 The architecture is the same, but the difference is that in this embodiment, the intersection description information is composed of the audio-visual source devices 30a-30d with the most intersection of description meta-information. Figure 7A In the process, switching method 4a in steps 40a-42a is basically similar to the process of steps 40-42 described above, and will not be repeated here. When proceeding to step 43a, the intersection calculation performed by controller 22 differs somewhat from the aforementioned embodiment. Figure 6 For example, among the four audio-visual source devices 30a-30d, the audio-visual source devices 30a-30c have the most overlapping description information because they share a common resolution of 1920x1080 60p. However, audio-visual source device 30d does not share a common resolution with audio-visual source devices 30a-30c. Therefore, in this embodiment, the controller 22 uses audio-visual source devices 30a-30c, which share the most common resolution of 1920x1080 60p, as the intersection description information. In one embodiment, the intersection description information of the audio-visual source devices 30a-30c is stored in memory, and the virtual unit 25 receives the intersection description information generated by the controller 22 to build a virtual device for the audio-visual source devices 30a-30d based on the intersection description information. In another embodiment, in addition to receiving the intersection description information generated by the controller 22 to establish a first virtual device about the audio-visual source devices 30a-30c, the virtual unit 25 also receives description meta information that does not share a common resolution, such as the description meta information of the audio-visual source device 30d, in order to establish a second virtual device about the audio-visual source device 30d based on the description meta information. This method can shorten the time required for the system to enumerate UVC when switching from the audio-visual source devices 30a-30c to the audio-visual source device 30d in the future.

[0030] After obtaining the intersection description information, steps 44a-46a are performed, similar to steps 44-46 described above, and will not be repeated here. After step 46a, the controller 22 continuously monitors whether the user switches to another audio-visual source device (step 47a). If not, the multimedia signal from the original audio-visual source device continues to play (step 47b). If a switch is made, process A is executed. Please refer to [link to relevant documentation]. Figure 7B As shown, in process A, the controller first determines whether the descriptive elements of the audio / video source devices 30a-30d selected by the switching signal are within the intersection description information (as in step 48a). In one embodiment of the determination in step 48a, the controller 22 has a storage unit that stores the intersection description information. The intersection description information records the audio / video source devices 30a-30d connected to each connection port. Therefore, when a switching signal is generated, the controller can determine which audio / video source device 30a-30d corresponds to the target connection port and whether the descriptive element information of the corresponding audio / video source device 30a-30d is within the intersection description information. In another embodiment of the determination in step 48a, the controller 22 confirms which connection port is the target connection port based on the switching signal, and then determines whether the descriptive element information of the audio / video source device 30a-30d corresponding to the target connection port belongs to the intersection description information before outputting it to the playback device. When the descriptive metadata of the selected audio / video source devices 30a-30d is included in the intersection descriptive metadata, the controller 22 enables the selected audio / video source devices 30a-30d to communicate with the playback device 31 according to the first communication connection (step 48b), which is as follows: Figure 5 The process described above will not be repeated here.

[0031] Conversely, when the descriptive metadata of one of the selected audio / video source devices 30a-30d is not included in the intersection descriptive information, the controller 22 establishes a second communication connection with the playback device 31 based on the descriptive metadata of the selected audio / video source device 30a-30d (step 48c). Figure 6 To illustrate, when a user switches to the selected audio / video source device 30d, since the resolution in the metadata of the audio / video source device 30d is not within the intersection description information (i.e., the metadata of the audio / video source device 30d does not have the resolution of 1920x1080 60p as in the intersection description information), the controller 22 will re-enumerate the metadata of the multimedia device 30d with the playback device 31 to establish a second communication connection. Afterwards, the playback device 31 can receive and display the multimedia signal of the selected audio / video source device 30d according to the second communication connection for playback (step 49a).

[0032] In summary, the switching device and the switching method provided by the present application can form intersection description information by intersecting the description information output by each video and audio source device. When a new video and audio source device is selected, if the description information of the selected video and audio source device is within the intersection description information, the playing device continues to use the communication connection between the playing device and the video and audio source device before the switching, thereby saving the time required for re-listing when the video and audio source device is switched. In other words, the intersection description information is related to the video and audio information of some video and audio source devices, and the intersection description information is the part common to at least two description information, and the switching device establishes a communication connection with the playing device according to the intersection description information. It is to be noted that although the aforementioned description information is described in terms of resolution, but this is not a limitation, for example, encoding mode information, channel number information or sampling rate, etc. can also be examples of the description information, and can be implemented according to the aforementioned spirit.

[0033] The above is only to describe the preferred embodiments or examples of the technical means adopted by the present application to solve the problems, and is not intended to limit the scope of the patent implementation of the present application. That is, any equivalent changes and modifications made in accordance with the scope of the present application are covered by the scope of the present application.

Claims

1. A switching device, characterized by The application includes: a plurality of USB interfaces, each of the USB interfaces coupled to an audio / video source device, each of the audio / video source devices including description metadata; an output interface coupled to a playback device; and a controller coupled between each of the USB interfaces and the output interface, the controller obtaining intersection description metadata from an intersection of at least two of the plurality of description metadata, and the controller establishing a first communication link with the playback device via the intersection description metadata. The controller includes a switching unit coupled to each of the audio / video source devices, the switching unit generating a switching signal to couple one of the plurality of audio / video source devices to the playback device, wherein when the controller selects another of the audio / video source devices to couple to the playback device according to the switching signal and the description metadata of the another of the audio / video source devices is included in the intersection description metadata, the playback device communicates with the selected another of the audio / video source devices via the first communication link.

2. The switching device of claim 1, wherein When the controller determines that the description metadata of the selected one of the audio / video source devices is not included in the intersection description metadata according to the switching signal, the controller establishes a second communication link with the playback device according to the description metadata of the selected one of the audio / video source devices.

3. The switching device of claim 2, wherein The description metadata is one or any combination of resolution metadata, encoding method metadata, channel number metadata, and sampling rate metadata.

4. The switching device of claim 1, wherein The controller further includes a virtual unit coupled to the output interface, the virtual unit establishing the first communication link with the playback device via a first virtual device according to the intersection description metadata.

5. The switching device of claim 1, wherein The application includes:

6. A switching method of a switching device, characterized by, recording, by a controller, description metadata output from each of a plurality of audio / video source devices; obtaining, by the controller, intersection description metadata from an intersection of at least two of the plurality of description metadata; and establishing, by the controller, a first communication link with a playback device via the intersection description metadata. The application further includes:

7. The handover method of claim 6, wherein, selecting, by the controller, one of the plurality of audio / video source devices to couple to the playback device according to a switching signal; and when the controller selects another of the audio / video source devices to couple to the playback device according to the switching signal and the description metadata of the another of the audio / video source devices is included in the intersection description metadata, the playback device communicates with the selected another of the audio / video source devices via the first communication link. The application further includes: selecting, by the controller, one of the plurality of audio / video source devices to couple to the playback device according to a switching signal; and 8. The handover method of claim 7, wherein, when the description metadata of the selected one of the audio / video source devices is not included in the intersection description metadata according to the switching signal, the controller establishes a second communication link with the playback device according to the description metadata of the selected one of the audio / video source devices. The description metadata is one or any combination of resolution metadata, encoding method metadata, channel number metadata, and sampling rate metadata. The step of establishing the first communication link further includes: establishing, by a virtual unit, the first communication link with the playback device via a first virtual device according to the intersection description metadata.

9. The handover method of claim 6, wherein, ​ 10. The handover method of claim 6, wherein, ​ ​

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