CN117749969A

CN117749969A - Video playing system and method

Info

Publication number: CN117749969A
Application number: CN202311745974.8A
Authority: CN
Inventors: 彭俊良
Original assignee: Chipone Technology Beijing Co Ltd
Current assignee: Chipone Technology Beijing Co Ltd
Priority date: 2023-12-18
Filing date: 2023-12-18
Publication date: 2024-03-22

Abstract

The present disclosure relates to a video playing system and method, wherein the master device is connected with the slave device through a video port, and when the access of the slave device is detected, link training with the slave device is started; in the link training, the first N times of link training all send training failure indication information, and under the condition that the training failure indication information is received, the voltage amplitude and/or pre-emphasis amplitude of a sending signal are improved by an adjusting instruction, the link training with the slave equipment is restarted until the training success indication information sent by the slave equipment is received, the link training is completed, and playing information is sent to the slave equipment for video playing. The embodiment of the disclosure can improve the communication quality of the established link and avoid the error from influencing the display quality in the process of transmitting the video data stream by the system.

Description

Video playing system and method

Technical Field

The disclosure relates to the field of display technologies, and in particular, to a video playing system and a video playing method.

Background

DisplayPort (DP for short) is a standard DisplayPort developed by the PC and chip manufacturer alliance, and the Video Electronics Standards Association (VESA) standard digital video interface standard DisplayPort will add support for high definition audio signal transmission while transmitting video signals, while supporting higher resolution and refresh rate. The device can support single-channel, unidirectional and four-line connection, the data transmission rate under the current latest DP1.4 standard reaches 32.4Gbps, and the single-lane transmission rate reaches 8.1Gbps. It is sufficient to transmit uncompressed high resolution and high refresh rate video and related audio while also supporting a bi-directional auxiliary channel of 1Mbps for device control and in addition supporting 8, 10 and 12 bit color depths.

The DP interface has the advantage over other interfaces (e.g., HDMI interface) that it supports higher resolution and refresh rate and is more powerful. At present, there is a scheme of realizing connection through the patch cord, but because the patch cord has different quality due to different price and brands, the quality of the wire is different, and data transmission in a high-speed channel causes errors, and the picture is abnormal, so the using effect is poor.

Disclosure of Invention

According to an aspect of the present disclosure, there is provided a video playback system, the system comprising a master device and a slave device, the master device and the slave device being connected through a video port, wherein,

the master device is configured to: when the access of the slave device is detected, starting the link training with the slave device;

the slave device is configured to: in the link training, the first N times of link training send training failure indication information, wherein the training failure indication information comprises a restarting link training instruction and a parameter adjusting instruction, and the N times of link training comprises at least one successful training, wherein N is more than or equal to 1 and is an integer;

the master device is further configured to: and under the condition that the training failure indication information is received, the voltage amplitude and/or the pre-emphasis amplitude of a sending signal are increased according to a parameter adjustment instruction in the training failure indication information, and the link training with the slave device is restarted according to a restarting link training instruction in the training failure indication information until the training success indication information sent by the slave device is received, the link training is completed, and playing information is sent to the slave device for video playing.

In one possible implementation, the link training includes:

clock recovery training, wherein the slave device recovers a clock signal from data sent by the master device so as to keep clock synchronization with the master device;

the slave equipment carries out channel equalization training according to the training mode information sent by the master equipment so as to realize channel equalization;

wherein the training success includes the clock recovery training success, and/or the clock recovery training and the equalization training success.

In one possible implementation, before performing the clock recovery training and the equalization training, the link training further includes: training initialization, wherein the master device reads the display port configuration data and the extended display identification data of the slave device;

in one possible implementation, after performing the clock recovery training and the equalization training, the link training further includes: and verifying the display port configuration data, wherein the master device reads the display port configuration data of the slave device and verifies whether the display port configuration data is stable or not.

In a possible embodiment, the voltage amplitude comprises M levels and the pre-emphasis amplitude comprises K levels, wherein the higher the level, the higher the voltage amplitude or the pre-emphasis amplitude, wherein N is less than or equal to m+k-2 in case of adjusting the voltage amplitude alone or the pre-emphasis amplitude alone in each link training, N is less than or equal to M-1, N is less than or equal to K-1 in case of adjusting the voltage amplitude and the pre-emphasis amplitude synchronously in each link training.

In a possible implementation manner, the step of increasing the voltage amplitude and/or the pre-emphasis amplitude of the transmission signal according to the parameter adjustment instruction in the training failure indication information includes:

the voltage amplitude and/or the pre-emphasis amplitude of the transmitted signal are increased by a preset number of steps.

In one possible embodiment, 1.ltoreq.N.ltoreq.3 and N is an integer, M and K are integers greater than or equal to 4, the predetermined number of stages being 1.

In a possible embodiment, the slave device is further configured to: and for the (n+1) th and subsequent link training, sending training failure indication information or training success indication information according to the actual result of the link training.

In one possible embodiment, the slave device includes a display panel including any one of a liquid crystal display panel, an organic light emitting diode display panel, a quantum dot light emitting diode display panel, a mini light emitting diode display panel, and a micro light emitting diode display panel.

According to an aspect of the present disclosure, there is provided a video playing method, which is applied to a video playing system, the system including a master device and a slave device, the master device and the slave device being connected through a video port, wherein the method includes:

The master device starts link training with the slave device when the access of the slave device is detected;

in the link training, the slave devices send training failure indication information for the first N times of link training, wherein the training failure indication information comprises a restarting link training instruction and a parameter adjustment instruction, and the N times of link training comprise at least one successful training, wherein N is more than or equal to 1 and is an integer;

and under the condition that the training failure indication information is received, the master equipment increases the voltage amplitude and/or the pre-emphasis amplitude of a sending signal according to a parameter adjustment instruction in the training failure indication information, restarts the link training with the slave equipment according to a restarting link training instruction in the training failure indication information until the training success indication information sent by the slave equipment is received, completes the link training, and sends playing information to the slave equipment for video playing.

In one possible implementation, the link training includes:

The slave equipment carries out channel equalization training according to the training mode information put by the master equipment so as to realize channel equalization;

According to an aspect of the present disclosure, there is provided a video playing method, which is applied to a master device in a video playing system, the system including a master device and a slave device, the master device and the slave device being connected through a video port, wherein the method includes:

Under the condition that training failure indication information from the slave equipment is received, the voltage amplitude and/or pre-emphasis amplitude of a sending signal is increased according to a parameter adjustment instruction in the training failure indication information, and link training with the slave equipment is restarted according to a restarting link training instruction in the training failure indication information until training success indication information sent by the slave equipment is received, the link training is completed, playing information is sent to the slave equipment for video playing,

in the link training, the first N times of link training are performed, the slave devices all send training failure indication information, the training failure indication information comprises a restarting link training instruction and a parameter adjusting instruction, and the N times of link training comprise at least one training success, wherein N is more than or equal to 1 and is an integer.

According to the embodiment of the disclosure, in the link training, the first N times of link training all send training failure indication information, the link training is forced to fail, the voltage amplitude and/or pre-emphasis amplitude of a sent signal are improved, a link training instruction is restarted to restart the link training with the slave device until the training success indication information sent by the slave device is received, the link training is completed, the communication quality of an established link can be improved, and the problem that errors affect the display quality in the process of transmitting video data streams by a system is avoided.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. Other features and aspects of the present disclosure will become apparent from the following detailed description of exemplary embodiments, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the disclosure and together with the description, serve to explain the technical aspects of the disclosure.

Fig. 1 shows a schematic diagram of a video playback system according to an embodiment of the present disclosure.

Fig. 2 shows a schematic diagram of a master device communicating with a slave device in a DP protocol.

Fig. 3 shows a schematic diagram of link training according to an embodiment of the present disclosure.

Fig. 4 shows a schematic diagram of link training according to an embodiment of the present disclosure.

Fig. 5 shows a comparison graph of display effects of a technical scheme employing an embodiment of the present disclosure and a technical scheme not employing an embodiment of the present disclosure.

Fig. 6 shows a flowchart of a video playing method according to an embodiment of the present disclosure.

Fig. 7 shows a flowchart of a video playing method according to an embodiment of the present disclosure.

Detailed Description

Various exemplary embodiments, features and aspects of the disclosure will be described in detail below with reference to the drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. Although various aspects of the embodiments are illustrated in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

In the description of the present disclosure, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate description of the present disclosure and simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be configured and operated in a particular orientation, and thus should not be construed as limiting the present disclosure.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present disclosure, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the present disclosure, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the terms in this disclosure will be understood by those of ordinary skill in the art as the case may be.

The word "exemplary" is used herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

The term "and/or" is herein merely an association relationship describing an associated object, meaning that there may be three relationships, e.g., a and/or B, may represent: a exists alone, A and B exist together, and B exists alone. In addition, the term "at least one" herein means any one of a plurality or any combination of at least two of a plurality, for example, including at least one of A, B, C, and may mean including any one or more elements selected from the group consisting of A, B and C.

Furthermore, numerous specific details are set forth in the following detailed description in order to provide a better understanding of the present disclosure. It will be understood by those skilled in the art that the present disclosure may be practiced without some of these specific details. In some instances, methods, means, elements, and circuits well known to those skilled in the art have not been described in detail in order not to obscure the present disclosure.

Referring to fig. 1, fig. 1 shows a schematic diagram of a video playing system according to an embodiment of the disclosure.

As shown in fig. 1, the system includes a master device (Source) 10 and a slave device (Sink) 20, the master device 10 and the slave device 20 being connected through a video port, wherein,

the master device 10 is configured to: initiating Link Training (Link Training) with the slave device 20 when access to the slave device 20 is detected;

the slave device 20 is configured to: in the link training, the first N times of link training send training failure indication information, wherein the training failure indication information comprises a restarting link training instruction and a parameter adjusting instruction, and the N times of link training comprises at least one successful training, wherein N is more than or equal to 1 and is an integer;

the master device 10 is also configured to: under the condition that the training failure indication information is received, the Voltage amplitude (Voltage swing) and/or Pre-emphasis amplitude (Pre-emphasis) of a sending signal are increased according to a parameter adjustment instruction in the training failure indication information, and link training with the slave device 20 is restarted according to a restarting link training instruction in the training failure indication information until the training success indication information sent by the slave device 20 is received, the link training is completed, and playing information is sent to the slave device 20 for video playing.

According to the embodiment of the disclosure, in the link training, whether the first N times of link training succeed or fail, training failure indication information is sent for each time of training, the link training is forced to fail, the voltage amplitude and/or pre-emphasis amplitude of a sending signal are improved, a link training instruction is restarted to restart the link training with the slave device 20 until the training success indication information sent by the slave device 20 is received, the link training is completed, the communication quality of an established link can be improved, and the problem that errors affect the display quality in the process of transmitting video data streams by a system is avoided.

The embodiments of the present disclosure are not limited to a particular type of video port, which may include a DP port, for example.

The following deviations exist due to the master device 10, the slave device 20: the individual deviation of the master device 10, the deviation of the connector, the deviation of the connecting line between the master device 10 and the slave device 20, the deviation of the receiving end connector and the individual deviation of the slave device 20 are difficult to avoid in the production and manufacture process for a plurality of video playing systems, the deviations cause different link quality of each video playing system, even some video playing systems have different link quality requirements for transmitting video information, the embodiments of the present disclosure can apply each video playing system, and by forcedly improving the voltage amplitude and/or pre-emphasis amplitude of the transmitting signal, each video playing system can establish stronger link quality, compensate the defect of poor link quality caused by the deviation in the production and manufacture process, and do not need to increase the hardware circuit cost.

The embodiments of the present disclosure are not limited to a specific type of the master device 10, the slave device 20, and the master device 10 may be a processing component or a terminal having a processing component, for example.

In one example, the processing component includes, but is not limited to, a separate processor, or a discrete component, or a combination of a processor and a discrete component. The processor may include a controller in an electronic device having the functionality to execute instructions, and may be implemented in any suitable manner, for example, by one or more Application Specific Integrated Circuits (ASICs), digital Signal Processors (DSPs), digital Signal Processing Devices (DSPDs), programmable Logic Devices (PLDs), field Programmable Gate Arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic elements. Within the processor, the executable instructions may be executed by hardware circuits such as logic gates, switches, application specific integrated circuits (Application Specific Integrated Circuit, ASIC), programmable logic controllers, and embedded microcontrollers.

In one example, the terminal device may be, for example, a User Equipment (UE), a mobile device, a User terminal, a handheld device, a computing device, or an in-vehicle device, and some examples of the terminal are: a Mobile Phone, a tablet, a notebook, a palm, a Mobile internet device (Mobile Internetdevice, MID), a wearable device, a Virtual Reality (VR) device, an Augmented Reality (AR) device, a wireless terminal in industrial control (Industrial Control), a wireless terminal in unmanned driving (Selfdriving), a wireless terminal in teleoperation (Remote medical Surgery), a wireless terminal in Smart Grid (Smart Grid), a wireless terminal in transportation security (Transportation Safety), a wireless terminal in Smart City (Smart City), a wireless terminal in Smart Home (Smart Home), a wireless terminal in the internet of vehicles, and the like. For example, the server may be a local server or a cloud server.

In one possible implementation, the slave device 20 may include a display panel, where the display panel includes any one of a liquid crystal display panel, an organic light emitting diode display panel, a quantum dot light emitting diode display panel, a mini light emitting diode display panel, and a micro light emitting diode display panel, and may also be a display screen or the like.

Illustratively, as shown in fig. 1, the master device 10 is connected to the slave device 20 through a Main link (Main link), an AUX CH auxiliary channel, and an HPD (hot plug detect) signal line. In the connection of the DisplayPort standard, the main link comprises four pairs of differential signal lines, or four main channels (4 lanes), image data, metadata, protocol control commands and the like are transmitted by using the main link, and one, two or four paths (Lane) can be used for transmitting data according to the selection of the quantity of the display data. In addition, displayPort defines three different transmission rates, each of which can be selectively transmitted using 1.62Gbit/s, 2.7Gbit/s, 5.4Gbit/s, or 8.1 Gbit/s. The AUX CH auxiliary channel may be a 1Mbps bi-directional half duplex channel that may be used for auxiliary Link Training (Link Training), DSC (Display Stream Compression, showing compressed streams) and FEC (Forward Error Correction forward error correction) configuration, DPCD register status, HDCP authentication and EDID exchange. HPD (Hot Plug) is an interruption mechanism for connection detection, link failure.

In one possible implementation, before performing the clock recovery training and the equalization training, the link training may further include: training initialization, wherein the master device 10 reads display port configuration data DPCD and extended display identification data EDID of the slave device 20;

in one possible implementation, after performing the clock recovery training and the equalization training, the link training further includes: DPCD verification, the master device 10 reads the display port configuration data DPCD of the slave device 20, and verifies whether DPCD is stable.

Referring to fig. 2, fig. 2 shows a schematic diagram of a master device 10 and a slave device 20 in a DP protocol.

In one example, as shown in FIG. 2, when a slave device 20 establishes a connection with a master device 10, after the slave device 20 is ready, a hot plug signal is sent to the master device 10 over the HPD signal line indicating that there is a slave device 20 plugged in.

The master device 10 establishes a connection with the slave device 20 through Link Training before sending video information to the slave device 20, and Link Training is a very important Link for DP initialization during the transmission process of a DP signal, commonly known as DP handshake. In the handshake process, the DP master device 10 reads the display port configuration data DPCD and the extended display identification data EDID of the DP slave device 20, where DPCD is used to announce the port performance of the DP device, and configure the port function and the transmission characteristics, where EDID is used to represent the capability, parameters, etc. of the picture that the slave device 20 can display, such as the manufacturer of the display, EDID version, display size, supported color space, resolution, etc., and configures the DPCD of the slave device 20 according to the optimal transmission characteristics to achieve the optimal transmission performance. When the DP master 10 detects the HPD event of the slave 20, a series of initialization processes such as EDID reading, DPCD reading and writing are completed between the master 10 and the slave 20, the master 10 starts a link training link, and then reads DPCD link configuration information to perform DPCD verification to determine whether the link is stable, and in the case of determining that the link is stable, sends a confirmation signal MSA to the slave 20 to tell the slave 20 that everything is ready, and then the master 10 sends video information to the slave 20 to play.

In one possible implementation, the link training may include:

clock Recovery (CR) training, the slave device 20 recovering a Clock signal from data transmitted from the master device 10 to maintain Clock synchronization with the master device 10; the CR training is the first training purpose of the master device 10 and the slave device 20 to establish synchronization, and in order for the slave device 20 to recover the clock from the character string sent by the master device 10, only the clock recovered correctly (i.e. the clocks of the slave device 20 and the master device 10 remain synchronized) can lock the characters correctly from the data stream to recover the correct data. CR training may be considered successful when the slave device 20 successfully recovers the clock signal. In the CR link, the master device 10 repeatedly reads the CR status of the slave device 20, and adjusts the Voltage swing (Voltage swing) and/or Pre-emphasis (Pre-phase) of the slave device 20 until the CR Done is read out and the EQ training is performed.

In one possible implementation, the link training may include:

equalization (EQ) training, the slave device 20 performs channel equalization training according to training mode information sent by the master device 10, so as to implement channel equalization; the EQ training is for channel equalization, and similar to the CR process, the EQ link, the master device 10 will also repeatedly read the EQ state of the slave device 20 and configure the voltage swing and pre-emphasis until the EQ link is completed. For example, the master device 10 transmits training pattern information pattern to start EQ training. After waiting for a specified time, reading the values of the three bits specified by the receiver DPCD memory, if the values of all the bits are read to be 1, indicating that training is successful, if not all the bits are 1, continuing to wait for the specified time, and then continuing to read the values of the three bits.

The above description of CR training, EQ training is exemplary and should not be taken as limiting the embodiments of the present disclosure, and one skilled in the art may implement CR training, EQ training with reference to the definition of the DP standard.

In one possible implementation, the training success includes the clock recovery training success, and/or the clock recovery training and the equalization training both succeed.

The embodiment of the disclosure does not limit the magnitude of the preset progression, and a person skilled in the art may set the preset progression according to actual situations and needs, and in a possible implementation manner, the preset progression may be 1.

The disclosed embodiments can increase the transmission strength of a signal by increasing the voltage amplitude and/or pre-emphasis amplitude of the transmitted signal, wherein the pre-emphasis technique is to enhance the high frequency component of the signal at the beginning of the transmission line to compensate for the greater attenuation of the high frequency component in the transmission link. Since the frequency of a signal is mainly determined by the speed at which the signal level changes, the high frequency component of the signal mainly occurs at the rising and falling edges of the signal, and the pre-emphasis technique is to enhance the amplitude at the rising and falling edges of the signal.

The specific size of N is not limited in the embodiments of the present disclosure, and may be set by those skilled in the art according to actual situations and needs. In a possible embodiment, the voltage amplitude comprises M levels and the pre-emphasis amplitude comprises K levels, wherein the higher the level, the higher the voltage amplitude or the pre-emphasis amplitude, wherein N is less than or equal to m+k-2 in case of adjusting the voltage amplitude alone or the pre-emphasis amplitude alone in each link training, N is less than or equal to M-1, N is less than or equal to K-1 in case of adjusting the voltage amplitude and the pre-emphasis amplitude synchronously in each link training. This ensures that the forced voltage amplitude and/or pre-emphasis amplitude can be stepped up during the first N training steps and the number of steps up to is adjusted by the size of N, which can be considered as the minimum number of steps required.

In one possible time-limited manner, the slave device is further configured to: and for the (n+1) th and subsequent link training, sending training failure indication information or training success indication information according to the actual result of the link training. Therefore, the excessive high-power consumption caused by the excessively high level can be avoided on the premise of ensuring the minimum level meeting the requirement.

For example, assuming that the voltage amplitude and the pre-emphasis amplitude are synchronously adjusted, the voltage amplitude and the pre-emphasis amplitude respectively comprise 4 levels, namely levels 0, 1, 2 and 3, n is 2, and the initial levels of the voltage amplitude and the pre-emphasis amplitude are all 0, so that in the previous 2 training, the 1 st training is assumed to be successful and the 2 nd training is failed, the 1 st training is forced to be failed, namely the previous 2 times are considered to be training failure, because the voltage amplitude and the pre-emphasis amplitude are synchronously adjusted, both the voltage amplitude and the pre-emphasis amplitude are forcedly upgraded to level 2, from the 3 rd training, if the training is successful, the levels of the voltage amplitude and the pre-emphasis amplitude are not increased any more, and if the training is failed, the levels of the voltage amplitude and the pre-emphasis amplitude can be upgraded to level 3. Therefore, the minimum grade requirement is met, and the waste of power consumption caused by the fact that the grade is too high to exceed the actual requirement is avoided.

For another example, it is assumed that the voltage amplitude and the pre-emphasis amplitude are respectively and independently adjusted, the voltage amplitude and the pre-emphasis amplitude respectively include 4 levels, that is, levels 0, 1, 2, 3, n are 4, and the initial levels of the voltage amplitude and the pre-emphasis amplitude are all 0, so that in the previous 4 times of training, the 1 st training, the 2 th training are assumed to be successful, the 3 rd training and the 4 th training are assumed to be failed, the 1 st training and the 2 nd training are forced to be failed, that is, the previous 2 times of training are assumed to be failed, because the voltage amplitude and the pre-emphasis amplitude are respectively adjusted, the voltage amplitude can be forcedly upgraded to level 2 in the previous 2 times of training, the pre-emphasis amplitude is forcedly upgraded to level 2 in the 3 rd training and the 4 th training, and the levels of the voltage amplitude and the pre-emphasis amplitude can be respectively upgraded to level 3 if the training is failed. Therefore, the minimum grade requirement is met, and the waste of power consumption caused by the fact that the grade is too high to exceed the actual requirement is avoided.

The embodiment of the disclosure does not limit the specific size of N, and does not limit the specific size of M, K, and the voltage amplitude and the pre-emphasis amplitude each include level 0 (level 0), level 1 (level 1), level 2 (level 2), and level 3 (level 3), that is M, K is 4, although in other embodiments, the voltage amplitude and the pre-emphasis amplitude may include other numbers of levels. As a preferred example, 1 n.ltoreq.3 and N is an integer, of course, N may also be an integer greater than 3, e.g. the voltage amplitude and the pre-emphasis amplitude may be adjusted separately, i.e. the voltage amplitude and the pre-emphasis amplitude may be adjusted 3 times respectively, in which case the maximum N may be 3, 4, 5, 6, etc. provided that the voltage amplitude is adjusted first and the pre-emphasis amplitude is adjusted. Of course, for this case, N corresponding to the voltage amplitude and the pre-emphasis amplitude may be set separately, that is, N corresponding to the voltage amplitude and the pre-emphasis amplitude are set 1 to 3 times.

Illustratively, at initialization, the voltage amplitude and the pre-emphasis amplitude may each be of the order 0.

Referring to fig. 3, fig. 3 shows a schematic diagram of link training according to an embodiment of the present disclosure.

For example, as shown in fig. 3, when the slave device 20 is powered up to complete parameter configuration, the slave device 20 may send an HPD to the master device 10, after the master device 10 completes initialization of the training, for example, may first start CR training, when CR training is successful, EQ training is performed, when EQ training is successful, it may indicate that current link training is successful, in this embodiment of the disclosure, assuming that N is set to 1, the training success includes the clock recovery training success, in this case, if CR training is successful, the slave device 20 sends training failure indication information, so that the master device 10 increases a Voltage amplitude (Voltage swing) and/or a Pre-emphasis amplitude (Pre-emphasis) of a transmission signal according to a parameter adjustment instruction in the training failure indication information, for example, increases the Voltage amplitude from a stage of swing 0 to swiping 1, and/or increases the Pre-emphasis amplitude from a stage of swiping 0 to swiping 1, then, according to a re-training instruction in the training failure indication information, and starts the slave device 20 to send the training failure indication information, and starts the slave device to play the training information until the slave device receives the training failure indication information and the slave device starts the training information.

Of course, the training success may include that the clock recovery training and the equalization training are successful, in this case, if the CR training is successful, then the EQ training is performed, and when the EQ training is successful, the slave device 20 sends training failure indication information, so that, when the master device 10 receives the training failure indication information, according to a parameter adjustment instruction in the training failure indication information, the Voltage amplitude (Voltage swing) of the sending signal and/or the Pre-emphasis amplitude (Pre-emphasis) are increased, for example, the Voltage amplitude is increased from swing0 by one level to swing 1, and/or the Pre-emphasis amplitude is increased from emphasis0 by one level to emphasis increased by emphasis 1, and then, according to a restart link training instruction in the training failure indication information, the link training with the slave device 20 is restarted, until the successful training instruction information sent by the slave device 20 is received, the link training is completed, and the playing information is sent to the slave device 20 for playing video.

Referring to fig. 4, fig. 4 shows a schematic diagram of link training according to an embodiment of the present disclosure.

As illustrated in fig. 4, in this embodiment of the present disclosure, the magnitudes of N corresponding to the CR training and the EQ training may also be set as needed, for example, if the CR training is started with swing0, when the first CR training is successful, the CR training may be forcedly controlled to fail, so as to request the master device 10 to increase the Voltage amplitude level from swing0 to swing 3 in turn, assume that the CR training N is set to 2, and when the Voltage amplitude is successful in swing 2, the slave device 20 performs EQ training from empface 0, assumes that the EQ training N is set to 1, and when the Pre-emphasis amplitude is successful in empface 1, and when the training is finally completed, the Voltage amplitude (Voltage swing) and the Pre-emphasis amplitude (Pre-empface) are set to swing 2 and empface 1, respectively, so that the master device 10 performs signal transmission.

The method of encoding a video stream by the master device 10 according to the embodiments of the present disclosure is not limited, and an 8b/10b encoding method may be used to encode the video stream to form video information and transmit the video information to the slave device 20.

Referring to fig. 5, fig. 5 shows a comparison graph of display effects of a technical scheme adopting an embodiment of the present disclosure and a technical scheme not adopting an embodiment of the present disclosure.

As shown in fig. 5, the technical solution not adopting the embodiment of the present disclosure has poor display quality due to a large number of errors occurring in the link quality (for example, errors occurring after the video stream encoded by the main device 10 is transmitted), and the technical solution adopting the embodiment of the present disclosure has good display quality.

Referring to fig. 6, fig. 6 shows a flowchart of a video playing method according to an embodiment of the present disclosure.

The method is applied to the video playing system shown in fig. 1, the system comprises a master device 10 and a slave device 20, the master device 10 and the slave device 20 are connected through a video port, and as shown in fig. 6, the method comprises:

step S11, in the case of detecting the access of the slave device 20, the master device 10 starts link training with the slave device 20;

step S12, in the link training, the slave devices 20 send training failure indication information for the first N times of link training, wherein the training failure indication information comprises a restarting link training instruction and a parameter adjustment instruction, and the N times of link training comprises at least one training success, wherein N is more than or equal to 1 and is an integer;

In step S13, when the master device 10 receives the training failure indication information, the voltage amplitude and/or the pre-emphasis amplitude of the transmission signal are increased according to the parameter adjustment instruction in the training failure indication information, and the link training with the slave device 20 is restarted according to the restart link training instruction in the training failure indication information until the training success indication information sent by the slave device 20 is received, so as to complete the link training, and send the play information to the slave device 20 for video playing.

In one possible implementation, the link training includes:

Clock recovery training, the slave device 20 recovering a clock signal from data transmitted from the master device 10 to maintain clock synchronization with the master device 10;

equalization training, wherein the slave device 20 performs channel equalization training according to training mode information put by the master device 10 to realize channel equalization;

In one possible implementation, before performing the clock recovery training and the equalization training, the link training further includes: training initialization, wherein the master device 10 reads display port configuration data DPCD and extended display identification data EDID of the slave device 20;

Referring to fig. 7, fig. 7 shows a flowchart of a video playing method according to an embodiment of the present disclosure.

The method is applied to a master device 10 in a video playing system as shown in fig. 1, the system comprising a master device 10 and a slave device 20, the master device 10 and the slave device 20 being connected through a video port, wherein the method comprises:

Step S21, in the case of detecting the access of the slave device 20, the master device 10 starts link training with the slave device 20;

step S22, under the condition that the training failure indication information from the slave device 20 is received, increasing the voltage amplitude and/or the pre-emphasis amplitude of the transmission signal according to the parameter adjustment instruction in the training failure indication information, restarting the link training with the slave device 20 according to the restarting link training instruction in the training failure indication information until the training success indication information sent by the slave device 20 is received, completing the link training, and sending the playing information to the slave device 20 for video playing, wherein in the link training, the first N times of link training are all sent with the training failure indication information, the training failure indication information includes the restarting link training instruction and the parameter adjustment instruction, and N times of link training include at least one training success, and N is greater than or equal to 1 and is an integer.

It will be appreciated that the above-mentioned method embodiments of the present disclosure may be combined with each other to form a combined embodiment without departing from the principle logic, and are limited to the description of the present disclosure. It will be appreciated by those skilled in the art that in the above-described methods of the embodiments, the particular order of execution of the steps should be determined by their function and possible inherent logic.

It should be noted that, the video playing method is a method example corresponding to the video playing system, and the specific description of the video playing system is referred to the previous description, and is not repeated herein.

The foregoing description of the embodiments of the present disclosure has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the various embodiments described. The terminology used herein was chosen in order to best explain the principles of the embodiments, the practical application, or the improvement of technology in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A video playing system is characterized in that the system comprises a master device and a slave device, wherein the master device and the slave device are connected through a video port,

2. The system of claim 1, wherein the link training comprises:

3. The system of claim 2, wherein the system further comprises a controller configured to control the controller,

before performing the clock recovery training and the equalization training, the link training further includes: training initialization, wherein the master device reads the display port configuration data and the extended display identification data of the slave device;

after performing the clock recovery training and the equalization training, the link training further includes: and verifying the display port configuration data, wherein the master device reads the display port configuration data of the slave device and verifies whether the display port configuration data is stable or not.

4. The system of claim 1, wherein the voltage amplitude comprises M levels and the pre-emphasis amplitude comprises K levels, wherein the higher the level, the higher the voltage amplitude or pre-emphasis amplitude,

Wherein, in each link training, under the condition of independently adjusting the voltage amplitude or independently adjusting the pre-emphasis amplitude, N is less than or equal to M+K-2,

in each link training, N is less than or equal to M-1 and N is less than or equal to K-1 under the condition of synchronously adjusting the voltage amplitude and the pre-emphasis amplitude.

5. The system of claim 4, wherein the step of increasing the voltage amplitude and/or the pre-emphasis amplitude of the transmission signal according to the parameter adjustment instruction in the training failure indication information comprises:

6. The system of claim 5, wherein 1 n.ltoreq.3 and N is an integer, M and K are integers greater than or equal to 4, and the predetermined number of stages is 1.

7. The system of claim 4, wherein the slave device is further configured to: and for the (n+1) th and subsequent link training, sending training failure indication information or training success indication information according to the actual result of the link training.

8. The system of claim 1, wherein the slave device comprises a display panel comprising any one of a liquid crystal display panel, an organic light emitting diode display panel, a quantum dot light emitting diode display panel, a mini light emitting diode display panel, and a micro light emitting diode display panel.

9. A video playing method, wherein the method is applied to a video playing system, the system comprises a master device and a slave device, the master device and the slave device are connected through a video port, and the method comprises:

10. A video playing method, wherein the method is applied to a master device in a video playing system, the system comprises the master device and a slave device, the master device and the slave device are connected through a video port, and the method comprises: