TWM608896U - Multimedia relay device - Google Patents

Abstract

The present invention provides a multimedia relay device, which includes a first transmission interface for receiving a multimedia signal, a second transmission interface for outputting the multimedia signal, a switching module, and a controller. The switching module further has a first transmission path, a second transmission path, and a switching unit. The switching unit selects the first transmission path so that the multimedia signal is transmitted to the second transmission interface through the first transmission path, wherein the second transmission path and the first transmission At least one of the impedance value of the path and the filtering frequency band is different. The controller controls the switching unit to select the second transmission path according to an electrical characteristic of the multimedia signal passing through the first transmission path.

Description

Multimedia relay device

This creation is a multimedia information quality adjustment technology, especially a multimedia relay device that can adjust the gain of the multimedia signal by changing the transmission path of the multimedia signal so that the image source can adjust the gain of the multimedia signal.

Please refer to Figure 1, which is a schematic diagram of the conventional image extension transmission system architecture. The multimedia signal source 10 in the image extension transmission system architecture 1 converts the multimedia signal (sound and image) output by the multimedia signal source 10 to the signal wire 12 through the dongle 11, and then transmits it to the switcher 13. The switcher 13 is then transmitted to the Internet 15 through the signal wire 14. The multimedia signal is transmitted to the remote terminal operating device 16 via the Internet 15 so that the display device can display pictures. In practical applications, due to long-distance transmission, or due to the compatibility of the multimedia output and the received signal, the multimedia signal gain of the multimedia signal source is often insufficient, which causes the image output by the back-end terminal operating device 16 to be unstable. , For example: the problem that causes jitter.

Among the conventional technologies, for example: US Patent Publication No. US7,853,731, teaches a technique that proposes an improvement method in the existing DisplayPort link training communication process, so that the link training process can be successful . In addition, for example, US Patent Publication No. US20150127187 also teaches a technique that can monitor specific parameters and appropriately adjust the degree of voltage swing. In this technology, a multimedia signal source (such as a mobile phone) that outputs a DisplayPort format image and a display device that receives the image are taught. In this technology, after the link training is successful, the temperature will affect the stability of the image signal. Therefore, the system detects the temperature of the multimedia signal source and automatically adjusts the voltage swing or frequency gain (pre-emphasis) according to the temperature.

For the switcher manufacturer as a relay device, it is not possible to directly control the gain of the multimedia image source. In addition, the image processing chip used in the switcher is also limited by the original manufacturer, so that the switcher manufacturer It is difficult to directly control the image processing chip in the switch to adjust the gain of the multimedia signal so that the display device or the terminal operating device can produce stable pictures. In summary, a multimedia relay device is needed to solve the problems of conventional technologies.

This creation is a multimedia relay device, through multiple kinds of line switching with at least one of different impedance values or filtering frequency bands, so that the multimedia image source can select different impedance values according to the state of the multimedia signal after linking training. Or filter the transmission path of the frequency band, after re-linking the training communication to change the voltage swing or frequency gain of the multimedia signal, increase the stability of the multimedia signal output by the display device, and adjust the gain strength of the multimedia signal source without limitation The support restrictions of manufacturers such as multimedia image sources or display devices, which further enhance the compatibility of multimedia relay device products.

In one embodiment, the present invention provides a multimedia relay device, which includes a first transmission interface for receiving a multimedia signal, a second transmission interface for outputting the multimedia signal, a switching module, and a controller. The switching module further has a first transmission path, a second transmission path, and a switching unit. The switching unit selects the first transmission path so that the multimedia signal is transmitted to the second transmission interface through the first transmission path, wherein the second transmission path and the first transmission At least one of the impedance value of the path and the filtering frequency band is different. The controller controls the switching unit to select the second transmission path according to an electrical characteristic of the multimedia signal passing through the first transmission path.

Hereinafter, various exemplary embodiments may be more fully described with reference to the accompanying drawings, and some exemplary embodiments are shown in the accompanying drawings. However, the present creative concept may be embodied in many different forms, and should not be construed as being limited to the exemplary embodiments set forth herein. To be precise, the provision of these exemplary embodiments makes this creation detailed and complete, and will fully convey the scope of this creation concept to those who are familiar with the technology. Similar numbers always indicate similar components. The multimedia relay device will be described below with various embodiments in conjunction with the drawings. However, the following embodiments are not intended to limit this creation.

Please refer to FIG. 2, which is a block diagram of an embodiment of the multimedia relay device created. In this embodiment, the multimedia relay device 2 includes a first transmission interface 20, a second transmission interface 21, a switching module 22, and a controller 24 (MCU). The multimedia relay device 2 can be an audio-visual extender, a KVM switch, an array switch (matrix), or a dongle between the switch and the multimedia source device 3, etc. In this embodiment, the conversion module is used as an embodiment of the multimedia relay device 2.

In this embodiment, the first transmission interface 20 and the second transmission interface 21 may be High Definition Multimedia Interface (HDMI), Digital Visual Interface (DVI) or display port (DisplayPort). In this embodiment, the DisplayPort interface is used for illustration. The multimedia relay device 2 is electrically connected to the multimedia source device 30 through the first transmission interface 20 and the signal transmission wire 91, and is coupled to the multimedia output device 32 through the second transmission interface 21. In this embodiment, the second transmission interface 21 is further electrically connected to the switch 31 through a signal transmission line 91, and the switch 31 is connected to the Internet 95 through a signal transmission line 92, and then electrically connected to the multimedia output device 32 . It should be noted that the switch 31 can be connected to multiple multimedia source devices 30. For the convenience of description, in this embodiment, only one multimedia source device 30 is used for description. In this embodiment, the multimedia output device 32 is a remote control terminal device (console), such as a desktop computer or a notebook computer, but it is not limited thereto. The multimedia output device 32 can receive the multimedia signal output from the multimedia relay device 2. The switch 31 in FIG. 2 is a KVM switch in this embodiment, but is not limited thereto. For example, in another embodiment, the switch 31 may also be an array switch with multiple inputs and multiple outputs. In this embodiment, the signal transmission wire 90 is a DidplayPort specification transmission wire, and the signal transmission wires 91 and 92 are network transmission wires, such as Cat. 5, Cat. 6, or other wires with similar transmission capabilities.

In addition, it should be noted that in this embodiment, the switch 31 is further electrically connected to the near-end multimedia output device 33, which is electrically connected to the switch 31 through a dedicated signal transmission wire 93, and is electrically connected to the switch 31 through a signal transmission wire 93. 93 In addition to receiving multimedia signals output from the multimedia source device 30, it can also transmit control signals generated by the multimedia output device 32, such as keyboard and mouse signals, to the multimedia source device 30 to control the multimedia source.装置30。 Device 30. Similarly, the remote multimedia output device 32 can also transmit control signals for controlling the multimedia source device 30 through the signal transmission wire 92. In other words, between the multimedia relay device 2 and the multimedia source device 30, there will also be a transmission line for transmitting keyboard or mouse control signals, such as a USB transmission line (not shown in the figure), and the local and remote multimedia output devices 32. How to transmit the control signal to the multimedia source device 30 is a conventional technology, and will not be repeated here. The multimedia source device 30, in another embodiment, may be a playback device, such as a DVD playback device. In addition, it should be noted that although the aforementioned remote or near-end multimedia output device 32 or 33 is a desktop computer or a notebook computer, in other embodiments, the multimedia output device 32 or 33 may be a single display or multiple A video wall composed of a display or a projector, etc.

The switching module 22 includes a plurality of transmission paths 22a-22d and a switching unit 23 in this embodiment. In this embodiment, each transmission path 22a-22d has an impedance value and a filtering frequency band, and at least one of the impedance value and filtering frequency band of each transmission path 22a-22d is different. It should be noted that the plurality of transmission paths 22a-22d include a first transmission path 22a, a second transmission path 22b, a third transmission path 22c, and a fourth transmission path 22d. The number of transmission paths is not limited to this embodiment, and different numbers of transmission paths can be set according to usage requirements. Taking the different impedance values of each transmission path 22a-22d as an example, the first transmission path 22a is a normal communication line, and the second to fourth transmission paths 22b-22d have RLC impedance composed of passive components such as resistance, inductance, and capacitance. Circuit. In this embodiment, the magnitude relationship of the impedance is the first transmission path 22a<the second transmission path 22b<the third transmission path 22c<the fourth transmission path 22d.

In another embodiment, if the filtering frequency bands are different, for example: the first transmission path 22a is a normal transmission circuit, the second transmission path 22b has a filtering circuit that filters out some frequency bands, and the third transmission path 22c filters The frequency range is larger than the second transmission path 22b, and the frequency range filtered by the fourth transmission path 22d is larger than the third transmission path 22c; or the first transmission path 22a is a normal transmission circuit, and the second transmission path 22b, the third transmission path 22c And the frequency bands filtered by the fourth transmission path 22d are different from each other. Through different filtering ranges or filtering out the transmission paths 22a-22d of specific frequency bands, the multimedia source device 30 can also adjust the voltage swing or frequency gain according to the result of the link training communication to enhance the strength of the multimedia signal.

The switching unit 23, in an embodiment, includes a first selector 230 and a second selector 231. The first selector 230 has a first input terminal 230a and a first output terminal 230b. The first input terminal 230a is coupled to the first transmission interface 20, and the first output terminal 230b is selectively connected to a plurality of transmission paths 22a-22d. One end is electrically connected. The second selector 231 has a second input terminal 231a and a second output terminal 231b. The second output terminal 231b is coupled to the second transmission interface 21. The second input terminal 231a is selectively connected to a plurality of transmission paths 22a-22d. The other end is electrically connected. The first and second selectors 230 and 231 can be implemented as multiplexers (MUX), for example.

Through the switching unit 23, the multimedia signal output by the multimedia source device 3 can be selected to be transmitted to the receiving physical layer component (Rx Phy) 25 through the first transmission interface 20 through one of the transmission paths 22a-22d for signal processing. In this embodiment, the receiving physical layer component 25 is a chip, which is electrically connected to the controller 24 (MCU), the switching unit 23, and the bidirectional auxiliary transmission channel AUX in the first transmission interface 20. The receiving physical layer component (Rx Phy) 25 processes the received multimedia signal and transmits it to the multimedia output device 32 or 33 via the second transmission interface 21. The detailed operation method will be described later. The controller 24 can detect the status of the multimedia signal in the receiving physical layer component (Rx Phy) 25, and then generate a control signal to control the switching unit 23 to select one of the transmission paths 22a-22d, so that the multimedia source device 3 selects one of them according to At least one of the impedance value or the filter frequency band of a transmission path 22a-22d changes the adjustment parameter of outputting the multimedia signal, wherein the adjustment parameter is a voltage swing or a frequency gain.

Since in the conventional technology, the audio-visual relay device transmits the signal of the link training communication between the multimedia source device and the multimedia output device, the multimedia source device will determine the voltage swing or frequency gain. After that, unless the link training communication is re-established, the voltage swing or frequency gain is already a fixed value, and there is no way to adjust the audio-visual relay terminal. The above-mentioned problems can be solved through the method of the authoring embodiment, and the operation method of the authoring will be explained below.

Before explaining the communication protocol, let's first explain the signal transmission style of DisplayPort. In the main transmission protocol of DisplayPort, the terminal specifications of DisplayPort, as shown in Figure 3, are mainly composed of 20 pins, including the main link composed of pins (pin 1~12), which is composed of pins 15- The two-way auxiliary transmission channel (AUX channel) formed by 17 and the hot plug detection (Hot_Plug) channel formed by pin 18 are used to receive the hot plug signal (Hot Plug Detect, HPD), and the rest are related to the power supply. (DP_PWR) pins 19 and 20, and configuration (config) pins 13-14. In the following embodiments, the main channel and the two-way auxiliary transmission channel will be mainly used for description. In Figure 2, the line ML is used to transmit the multimedia signal of the main channel, which includes three pairs of differential signals representing sound and video, and a pair of differential signals representing clock. Line AUX represents a two-way auxiliary transmission channel, which is a two-way half-duplex channel, which transmits the management and control signals of DisplayPort high-speed signals, such as VESA EDID, MCCS and DPMS standards, as well as link training communications.

As shown in FIG. 2, when the audio-visual relay device 2 completes the electrical connection with the multimedia source device 30 and the multimedia output device 32 or 33 and starts to power on, the first and second selection units 230 and 231 of the switching unit 23 are initially The preset transmission path is the first transmission path 22a. After that, the multimedia source device 30 and the multimedia relay device 2 conduct handshaking according to the communication protocol of multimedia transmission. The aforementioned communication protocol can be the HDMI communication protocol, or the DisplayPort (DP) communication protocol, etc., but it is not limited by this, as long as there is a communication mechanism for link training. In this embodiment, the DisplayPort communication protocol is used to illustrate.

First, the multimedia source device 30 and the receiving physical layer component (Rx Phy) 25 perform a handshake procedure of link training communication via the AUX line. After the handshaking process is completed, the multimedia source device 30 determines and transmits multimedia with a specific voltage swing or frequency gain through the main channel ML according to the result of the link training communication completed corresponding to the impedance of the first transmission path 22a The signal is given to the receiving physical layer component (Rx Phy) 25. The receiving physical layer component (Rx Phy) 25 processes the multimedia signal after receiving it, and stores the electrical characteristics of at least one unidirectional differential signal in the processed multimedia signal in the internal register 250. In one embodiment, the electrical characteristic is the voltage state value of whether the unidirectional differential signal voltage is stable or not, but it is not limited thereto. The register 250 may be a PLL register. Since the aforementioned voltage state value represents the stability of the multimedia signal, in one embodiment, if it is unstable, the picture seen by the multimedia output device 32 or 33 is It will be a problematic picture, such as: jitter or mosaic picture or unable to paint the situation. Conversely, if it is in a stable state, it means that the multimedia output device 32 or 33 can display the screen stably. In one embodiment, the controller 24 can read the PLL lock status (PLL lock status) in the physical layer element 25 through a channel connected to the physical layer element 25, such as an I _{2 C channel, for example, to read} Take the voltage state value stored in the register 250 to know whether the signal is stable.

In one embodiment, the differential signal is used as the clock differential signal for illustration. For example, after the physical layer component 25 receives the clock differential signal, under normal circumstances, it should be able to restore the clock differential signal. If it cannot be restored, the phase-locked loop state will show an unstable state. In the state, it may be that the voltage state value in the register 250 changes between 0 and 1, or it has been maintained at 0 (assuming that 0 represents an unstable voltage state, and 1 represents a stable voltage state). On the contrary, if If the clock differential signal is unlocked, the voltage will be in a stable state, such as 3.3V or 5V, so the voltage state value is 1. If the voltage state value is always in a stable state of 1, it means that the picture is stable; on the contrary, if the voltage state value is always in an unstable state where the value of the voltage state is always beating between 0 and 1, or is not even unlocked and is always in a state of 0 , Means that the gain of the multimedia signal output from the main channel ML where the multimedia source device 30 is located is insufficient.

The controller 24, in this embodiment, continuously monitors the state of the voltage state value, and when it finds an unstable state where the voltage state value is always beating between 0 and 1, or is not even unlocked and is always in a state of 0, The controller 24 controls the first and second selection units 230 and 231 of the switching unit 23 to select the second transmission path 22b with different impedances, and restart the link training communication. Since the impedance of the second transmission path 22b is greater than the impedance of the first transmission path 22a, the multimedia source device 30 increases the compensation gain due to the larger impedance of the second transmission path 22b during the link training communication process, for example: increasing the voltage Swing or increase frequency gain.

After that, the controller 24 will also detect the voltage state value stored in the internal register 250 of the receiving physical layer device (Rx Phy) 25, and determine whether to select transmission paths with different impedances according to the voltage state value. If the voltage state value is stable, the controller 24 further sends a control signal to control the first and second selection units 230 and 231 of the switching module 23 to switch back to the initial first transmission path 22a. It has the lowest impedance, so that in the subsequent multimedia signal transmission process, it can ensure that the multimedia output device 32 or 33 can stably produce pictures, because the multimedia output device 30 is produced by increasing the voltage swing corresponding to the high impedance or increasing the frequency gain. The multimedia signal, and the aforementioned multimedia signal is transmitted on the low impedance first transmission path 22a, so that it can be ensured that both the multimedia output device 32 or 33 can produce pictures stably. Conversely, if the voltage state value is still unstable, the controller 24 will control the switching module 23 to switch down to the next third transmission path 22c with an impedance greater than the second transmission path 22b, and so on, until The voltage state value stored in the register 250 is stable.

Please refer to FIG. 4, which is a block diagram of another embodiment of the multimedia relay device created. In this embodiment, the aforementioned multimedia relay device 2 is installed in the KVM switch 4. For the convenience of description, this embodiment only describes the video signal in the multimedia signal in the KVM switch 4. In this embodiment, the KVM switch 4 has first transmission interfaces 20a and 20b, which are respectively disposed on the housing of the KVM switch 4. The first transmission interface 20a is used to electrically connect with the multimedia input device 30a. The transmission interface 20b is used for electrically connecting with the multimedia input device 30b. The KVM switch 4 also has a second transmission interface 21 which is electrically connected to the multimedia output device 34. In this embodiment, the multimedia output device 34 is a display, but it is not limited to this. It may also be a video wall or a projector where multiple screens are spliced together. The KVM switch 4 has an image switch 40 and a control unit 41. The control unit 41 can choose to output images related to the multimedia input device 30a to the multimedia output device 34 or output images related to the multimedia input device 30b to the multimedia according to the user's manipulation. Output device 34.

In this embodiment, each of the multimedia source devices 30a and 30b is respectively coupled to the switching module 22 and the controller 24 to perform the aforementioned control and switching methods. Take the multimedia source device 30a as an illustration. Between the multimedia source device 30a and the receiving physical layer element 25, a switching unit 22 and a transmission path 22a-22d with different impedance passive components (RLC) or filter frequency bands are added to allow the controller 24 The state of the multimedia signal output by the multimedia source device 30a after the link training communication between the multimedia source device 30a and the receiving physical layer component 25 can be used to determine whether the multimedia signal is stably output to the multimedia output device 34. If it is unstable, select The different transmission paths 22b-22d and the new link training communication enable the multimedia source device 30a to adjust the gain of the multimedia signal. In one embodiment, when the controller 24 reads the PLL register 250 of the receiving physical layer component 25, it can determine whether the picture status is stable. If the picture is unstable, the controller 24 switches the transmission main channel line ML. The transmission path of the multimedia signal is, for example, switched from 22a to 22b, and the multimedia source device 30 and the receiving physical layer element 25 are re-engaged for link training communication, so that the multimedia source device 30 can output a larger increase in voltage swing or increase in frequency gain. After the end, the controller 24 immediately switches the line ML of the main transmission channel back to the initial first transmission path 22a with the lowest impedance, so that the gain-adjusted multimedia signal output by the multimedia source device 30 will not have high impedance. The attenuation of the transmission paths 22b-22d affects the reception of the receiving physical layer element 25.

In addition, it should be noted that after switching back to the first transmission path 22a, the controller 24 can continuously detect the electrical characteristics of the multimedia signal, that is, whether the voltage state value stored in the register 250 is stable. If the state of the multimedia signal is unstable, the controller 24 controls the switching module 22 to select another transmission path different from the first transmission path 22a, such as the third transmission path 22c, and then restarts the multimedia source device 30a and the receiving physical layer The link training communication between the components 25 allows the multimedia source device 30 to output a multimedia signal with a larger voltage swing or a larger frequency gain.

Based on the above, the multimedia relay device of this creation can switch through multiple lines with at least one of different impedance values or filter frequency bands, so that the multimedia image source can change the voltage of the multimedia signal after linking training. Swing or frequency gain to increase the stability of the multimedia signal output by the display device, so as to adjust the gain strength of the multimedia signal source without being limited to the support of manufacturers such as multimedia image sources or display devices, thereby enhancing the multimedia relay device products The effect of compatibility.

The above descriptions only describe the preferred implementations or examples of the technical means used in this creation to solve the problem, and are not used to limit the scope of implementation of the patent for this creation. That is to say, all the equivalent changes and modifications made in accordance with the scope of the creation patent application or made according to the scope of the creation patent are covered by the scope of the creation patent.

1: Image extension transmission system

10: Multimedia signal source

11: Conversion module

12: Signal wire

13: switcher

14: Signal wire

15: Internet

16: terminal operating device

2, 2a, 2b: Multimedia relay device

20: The first transmission interface

21: The second transmission interface

22: Switch module

22a: The first transmission path

22b: second transmission path

22c: third transmission path

22d: Fourth transmission path

23: switching unit

230: first selector

230a: first input

230b: first output

231: second selector

231a: second input

231b: second output

24: Controller

25: Receiving physical layer components

ML: Line

AUX: line

30: Multimedia input device

31: Switcher

32, 33: Multimedia output device

4: KVM switch

40: Video switcher

41: control unit

90, 91, 92, 93: signal transmission wire

95: Internet

Figure 1 is a schematic diagram of the conventional image extension transmission system architecture. Figure 2 is a block diagram of an embodiment of the creative multimedia relay device. FIG. 3 is a schematic diagram of an embodiment of the DisplayPort interface of the multimedia signal interface. Fig. 4 is a block diagram of another embodiment of a creative multimedia relay device.

2: Multimedia relay device

20: The first transmission interface

21: The second transmission interface

22: Switch module

22a: The first transmission path

22b: second transmission path

22c: third transmission path

22d: Fourth transmission path

23: switching unit

230: first selector

230a: first input

230b: first output

231: second selector

231a: second input

231b: second output

24: Controller

25: Receiving physical layer components

ML: Line

AUX: line

30: Multimedia input device

31: Switcher

32, 33: Multimedia output device

90, 91, 92, 93: signal transmission wire

95: Internet

Claims (6)

A multimedia relay device includes: a first transmission interface that receives a multimedia signal; a second transmission interface that outputs the multimedia signal; a switching module that includes: a first transmission path, a second transmission path, and a The switching unit selects the first transmission path so that the multimedia signal is transmitted to the second transmission interface through the first transmission path, wherein the impedance values of the second transmission path and the first transmission path and the filter frequency band are two At least one of them is different; and a controller that controls the switching unit to select the second transmission path according to an electrical characteristic of the multimedia signal passing through the first transmission path. The multimedia relay device according to claim 1, wherein the switching unit further has: a first selector having a first input terminal and a first output terminal, the first input terminal and the first transmission interface Coupled, the first output terminal is selectively electrically connected to one end of the first or second transmission path; and a second selector having a second input terminal and a second output terminal, the second output The terminal is coupled with the second transmission interface, and the second input terminal is selectively electrically connected with the other terminal of the first or second transmission path. The multimedia relay device according to claim 2, wherein the first selector is electrically connected with a channel for transmitting a unidirectional differential signal in the first transmission interface. The multimedia relay device according to claim 1, wherein there is a receiving physical layer element between the second transmission interface and the switching module, which is connected to the controller, the switching module, and the first One of the two-way auxiliary transmission channels in the transmission interface is electrically connected. The multimedia relay device according to claim 4, wherein the multimedia signal includes at least one unidirectional transmission differential signal, and the electrical characteristic of the multimedia signal is a voltage state value of one of the differential signals, The receiving physical layer component receives the multimedia signal, and generates the voltage state value associated with one of the differential signals passing through the first transmission path or the second transmission path and stores it in a register. The multimedia relay device according to claim 5, wherein the differential signal associated with the voltage state value is a clock differential signal, and the controller generates a control according to the voltage state value stored in the register The signal is used to control the switching module to select the second transmission path.

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