TWI582633B - Display system and display method - Google Patents

Description

Display system and display method

The present invention relates to a display system, and more particularly to a display system and a display method for playing video content with content protection using a USB display device.

Among the many interfaces used in personal computers and notebooks, the USB (Universal Serial Bus) interface is the most successful and the most widely used. In the current specification of the USB interface, there is no specific definition of audio and video applications, especially audio/video data with content protection (such as digital rights management DRM). For example, the content of a Blu-ray disc is encrypted using an Advanced Access Content System (AACS) encryption and decryption standard to protect audio/video content. In a conventional display system, the driver of the graphics processor can only transfer the original video data obtained to the display card. The processor will further determine whether the display card is output through an analog display interface (such as VGA, DSUB interface) or a digital display interface with data protection (such as HDMI, DisplayPort or DVI). The video file with high image resolution (such as Full High Definition) with content protection can only output through the digital display interface to have the original high image resolution. If the output is output through the analog display interface, the original high picture must be The quality resolution is reduced to the standard definition (Standard Definition).

Therefore, in the current software/hardware architecture of computer systems, if video content with content protection is to be played, users often cannot play video or audio with content protection (such as DHCP) through an external USB display card. News. Therefore, there is a need for a display system that can play video content with content protection using a USB display device.

The present invention provides a display system, including: a processor for decrypting a first encrypted video stream by a first encryption and decryption standard to obtain a first video stream, and using a second encryption and decryption standard The first video stream is encrypted to obtain a second encrypted video stream; a USB display device; a storage unit including a driver of the USB display device; and a chipset coupled to the processor, the USB display device, and The storage unit, wherein the processor executes the driver to decrypt the second encrypted video stream to obtain a second video stream, and decodes the second video stream to obtain a first video data; wherein the processor further obtains the obtained The video data is encrypted to obtain an encrypted video data, and the encrypted video data is transmitted to the USB display device; wherein the USB display device decrypts the encrypted video data to obtain a second video data, and plays the second video data on a display. .

The present invention further provides a display method for a display system, the display system comprising: a processor, a USB display device, a storage unit, and a chip set, wherein the storage unit includes a driver of the USB display device, And the chipset is coupled to the processor, the USB display device, and the storage unit, the method comprising: using the processor to decrypt the first encrypted video stream by using a first encryption and decryption standard to obtain a first Video stream, and encrypting the first video stream by a second encryption and decryption standard to obtain a second encrypted video stream; using the processor to execute the driver to decrypt the second encrypted video stream to obtain a second video stream And decoding the second video stream to Obtaining a first video data; using the processor to encrypt the obtained video data to obtain an encrypted video data, and transmitting the encrypted video data to the USB display device; using the USB display device to encrypt the video data Decrypting to obtain a second video data; and playing the decrypted second video data on a display by using the USB display device.

The present invention further provides a display system, comprising: a processor for decrypting a first encrypted video stream by using a first encryption and decryption standard to obtain a first video stream, and using a second encryption and decryption standard The first video stream is encrypted to obtain a second encrypted video stream; a USB display device; a storage unit including a driver of the USB display device; and a platform control hub coupled to the processor and the USB display device And the storage unit, wherein the processor executes the driver to decrypt the second encrypted video stream to obtain a second video stream, and decodes the second video stream to obtain a first video data; wherein the processing The device further encrypts the obtained video data to obtain an encrypted video data, and transmits the encrypted video data to the USB display device; wherein the USB display device decrypts the encrypted video data to obtain a second video message. Data and playing the second video material on a display.

The present invention further provides a display system, comprising: a processor for decrypting a first encrypted video stream by using a first encryption and decryption standard to obtain a first video stream, and using a second encryption and decryption standard The first video stream is encrypted to obtain a second encrypted video stream; a USB display device; a storage unit including a driver of the USB display device; and a chipset coupled to the processor, the USB display device, and The storage unit; wherein the processing The device executes the driver to transmit the second encrypted video stream to the USB display device; wherein the USB display device decrypts the second encrypted view stream to obtain a second video stream, and the second video stream is Decoding to obtain a video data; wherein the USB display device plays the decoded video data on a display.

The present invention further provides a display method for a display system, the display system comprising: a processor, a USB display device, a storage unit, and a chip set, wherein the storage unit includes a driver of the USB display device, And the chipset is coupled to the processor, the USB display device, and the storage unit, the method comprising: using the processor to decrypt the first encrypted video stream by using a first encryption and decryption standard to obtain a first Video stream, and encrypting the first video stream by a second encryption and decryption standard to obtain a second encrypted video stream; using the processor to execute the driver to transmit the second encrypted video stream to the USB display device; The USB display device decrypts the second encrypted video stream from the processor to obtain a second video stream; using the USB display device to decode the decrypted second video stream to obtain a video data; and utilizing The USB display device plays the video material on a display.

The present invention further provides a display system, comprising: a processor for decrypting a first encrypted video stream by using a first encryption and decryption standard to obtain a first video stream, and using a second encryption and decryption standard The first video stream is encrypted to obtain a second encrypted video stream; a USB display device; a storage unit including a driver of the USB display device; and a platform control hub coupled to the processor and the USB display device And the storage unit; wherein the processor executes the driver to transmit the second encrypted video stream to The USB display device, wherein the USB display device decrypts the second encrypted video stream to obtain a second video stream, and decodes the second video stream to obtain a video data; wherein the USB display device is further A display plays the decoded video material.

The above described objects, features and advantages of the present invention will become more apparent from the description of the appended claims.

1 is a functional block diagram showing a display system in accordance with an embodiment of the present invention. The display system 100 includes a processor 110, a graphics processor 120, a chipset 130, a first memory unit 140, a second memory unit 150, a storage unit 160, and a USB display device 170. Wafer set 130 serves as a bridge between the various components in display system 100. For example, the wafer set 130 can include a north bridge wafer 131 and a south bridge wafer 132. The north bridge wafer 131 and the south bridge wafer 132 are connected by an internal bus bar 133. The north bridge chip 131 is used to connect components with higher operating frequencies, such as the processor 110, the graphics processor 120, and the first memory unit 140 (eg, system memory). The south bridge wafer 132 is used to connect components with lower operating frequencies (such as PCI devices) and input/output peripheral devices, such as a USB display device 170 or an external playback device (such as a BluRay optical disk drive).

The first memory unit 140 is a system memory. When the processor 110 decrypts video data (such as the first encrypted audio stream and the first encrypted video stream) with content protection (for example, CSS or AACS), after decryption, after decryption The obtained audio/video temporary storage data (for example, the first audio stream and the first video stream) are first stored in the first memory unit 140. Further, the processor encrypts the first audio stream and the first video stream (for example, using AES), and the second encrypted audio stream and the second encrypted video stream generated by the encryption are also stored in the first memory unit 140. in. The second memory unit 150 is a graphics memory dedicated to the graphics processor 120 for storing graphics data of the graphics processor 120 or decoded video data.

The storage unit 160 stores an operating system 161, a first driver 162, and a second driver 163. The processor 110 executes the operating system 161 as a work platform. The first driver 162 is a dedicated driver of the graphics processor 120. The video data with content protection (for example, an H.264 video stream encrypted by the AES standard) can be decrypted and the video stream can be decoded by the graphics processor 120 (for example, H.264 video streaming).

In the first embodiment, the second driver 163 is a dedicated driver (also referred to as a hook driver) of the USB display device 170 for obtaining the first memory unit 140 through the processor 110. Two encrypted video streams. In more detail, after the second driver 163 obtains the second encrypted video stream, the second encrypted video stream is further decoded by the processor 110 to generate a second video stream, and the second executed by the processor 110. The driver 163 then decodes the second video stream to obtain the original first video material. Then, the processor 110 encrypts the decoded first video data to obtain the encrypted video data, and transmits the encrypted video data to the USB display device 170. The USB display device 170 decrypts the received encrypted video data to obtain a second video data, and can play the second video data on a display.

In the second embodiment, the second driver 162 is configured to obtain the second encrypted video stream from the first memory unit 140 through the processor 110 and transmit the second encrypted video stream to the USB display device 170. The USB display device 170 first decrypts the received second encrypted video stream to obtain a third video stream. It should be noted that in this embodiment, the USB display device 170 further includes a video decoder (not shown) for decoding the decrypted third video stream to obtain the original video data. Considering the efficiency of instant play, the video decoder (eg, H.264 decoder) in the USB display device 170 is typically implemented in a hardware circuit. The USB display device 170 then plays the decoded video data on a display.

In an embodiment, display system 100 can optionally include an external optical drive 180. The external optical disk drive 180 is coupled to the south bridge chip 132 for playing audio/video data with content protection (for example, AACS encryption). In another embodiment, the storage unit 160 can also selectively store the media archive 164 with content protection. The processor 110 may store the media archive 164 with content protection (eg, AACS encryption) by the storage unit 160 and perform data protection decryption.

2A is a functional block diagram showing a display system 200 in accordance with another embodiment of the present invention. Referring to FIG. 1 and FIG. 2A simultaneously, some of the component functions in the system 200A are the same as those in the display system 100, such as the chipset 230A (including the north bridge wafer 231A and the south bridge wafer 232A), and the storage unit 260A (including the operation). System 261A, first driver 262A and second driver 263A) and USB display device 270A. The difference between the display system 200A and the display system 100 is that the processor 210A includes a first core 211A and a second core 212A, wherein the first core 211A The function is the same as the processor 110, and the function of the second core 212A is the same as the graphics processor 120. In other words, the processor 210A integrates the functions of a general processor and a graphics processor (for example, an Intel Core 2 Duo processor), and the processor 210A further uses a unified memory architecture, that is, the first core. The 211A and the second core 212A access data are all using the memory unit 240A. In more detail, the memory unit 240A is a graphic memory in addition to the system memory.

2B is a functional block diagram showing a display system 200B in accordance with still another embodiment of the present invention. Referring to FIGS. 2A and 2B, some of the component functions in the system 200B are the same as those in the display system 200A, such as the storage unit 260B (including the operating system 261B, the first driver 262B, and the second driver 263B). And a USB display device 270B. The display system 200B differs from the display system 200A in that the display system 200B uses a platform control hub (PCH) 290 to replace some of the functions of the north bridge chip 231A in the display system 200A (such as an instant clock) and the south bridge. The full functionality of the chip 232A, and the processor 210B is coupled to the platform control hub 290 via a Direct Media Interface (DMI). The processor 210B (for example, an Intel i3, i5, i7 processor) includes a first core 211B, a second core 212B, and an integrated memory controller 213B, wherein the functions of the first core 211B and the second core 212B are respectively The same as the first core 211A and the second core 212A. It is noted that the memory unit 240B in the display system 200B is directly electrically connected to the integrated memory controller in the processor 210B, and the memory unit 240B is also integrated using the memory. The Unified Memory Architecture is used for the first core 211B (general processing core) and the second core 212B (graphic processing core) to access the data in the memory unit 240B through the integrated memory controller 213B.

For the present invention, regardless of the display system 100, 200A or 200B, a video file with high image resolution with content protection can be played by the USB display device. For convenience of explanation, the embodiment described later is exemplified by the display system 100 of Fig. 1. Those skilled in the art of the invention will appreciate that the operation of the display system 100 of the present invention can be applied to display systems 200A and 200B.

Figure 3A is a schematic diagram showing the software/hardware architecture of display system 100 in accordance with a first embodiment of the present invention. Please refer to FIG. 1 and FIG. 3A at the same time, and the processing flow of the software/hardware of the system 100 can be roughly divided into five stages of stages 310A-350A. Stage 310A may also be referred to as User mode unprotected infrastructure. For example, in stage 310A, display system 100 can play a video archive with content protection (eg, AACS encryption) by a playback software (eg, Power DVD, Media Player, etc.). Next, the processor 110 decrypts the video content with content protection (including the first encrypted audio stream and the first encrypted video stream) and proceeds to stage 320A.

Stage 320A may also be referred to as a User mode protected infrastructure. The processor 110 stores the first audio stream (such as stereo or Dolby code) obtained after decryption and the first video stream (for example, H.264 video stream) in the first memory unit 140, and then the first audio stream and The first video stream is encrypted by another data encryption and decryption standard (for example, AES, 3AES) to obtain a second encrypted audio stream and a second encrypted video. The stream is streamed, and the second encrypted audio stream and the second encrypted video stream are stored in the memory unit 140, and transmitted to the corresponding audio device (for example, the sound card) and the graphics processor 120, respectively, and enters the stage 330A. Note that in video content with content protection (eg, AACS) (eg, BluRay disc), the audio signal is less restricted, and the audio device can decrypt the second encrypted audio stream after receiving the second encrypted audio stream. The second audio stream is obtained, and then the second audio stream is decoded to obtain the original audio data for playing.

Stage 330A may also be referred to as Drivers Kernel Mode Protected Environment. In stage 330A, the processor 110 executes the second driver 163 to obtain the second encrypted video stream in the memory unit 140, and decrypts the second encrypted video stream to obtain the second video stream, and is processed by the graphics processor. 120 decodes the second video stream to obtain the first video material. Then, the processor 110 encrypts the decoded first video data (for example, using the AES standard) to obtain an encrypted video data, and transmits the encrypted video data to the USB display device 170, and proceeds to stage 340A. It should be noted that in stages 310A-330A, they are all part of the software, that is, the processor 110 is used to perform related encryption and decryption operations. It should be noted that, in stage 330A, the processor 110 is responsible for the decryption and decoding operations of the second encrypted video stream, and re-encrypts the obtained first video data, and transmits the encrypted video data to the USB display device 170.

In step 340A, the USB display device 170 first decrypts the received encrypted video data to obtain the second video data, and transmits the second video data to the display (not shown) through the analog display interface or the digital display interface. And enter stage 350A. Because of the second drive of the USB display device 170 The program 163 has directly obtained the second encrypted video stream from the first memory unit 140, and performs an operation of decrypting and decoding to obtain the first video material. However, the transmission path between the processor 110 and the USB display device 170 still needs to be re-encrypted, so the processor 110 encrypts the first video material (for example, using the AES standard) to obtain the encrypted video data. After the USB display device 170 decrypts the received encrypted video data, the second video can be obtained. No matter whether the USB display device 170 plays the original video data through the analog display interface or the digital display interface, the original video data is not limited. The screen of high image quality resolution is displayed in descending order. In stage 350A, the display can directly play video material from USB display device 170.

Figure 3B is a schematic diagram showing the software/hardware architecture of display system 100 in accordance with a second embodiment of the present invention. Please also refer to Figure 1 and Figures 3A and 3B of this case. The differences between Figures 3A and 3B are mainly in stages 330B and 340B. In stage 330B, the processor 110 executes the second driver 163, and the second encrypted video stream is acquired by the first memory unit 140 (for example, an AES encrypted H.264 video stream), and then the second encrypted video stream is obtained. Transfer to the USB display device 170. In stage 340B, USB display device 170 first decrypts the received second encrypted video stream to obtain a third video stream. Since the USB display device 170 has a video decoder (for example, an H.264 decoder), the USB display device 170 can directly decode the third video stream to obtain original video data, and display the obtained video data through analog display. The interface or digital display interface is transmitted to a display (not shown) and enters stage 350B. Stages 310B, 320B, and 350B in FIG. 3B are similar to stages 310A, 320A, and 350A in FIG. 3A, respectively, and details thereof will not be described herein.

It should be noted that, regardless of the 3A and 3B, the display system 100 can decode the video stream without using the graphics processor 120 or its first driver 162, but through the software (decoded by the processor 110, The video stream is decoded in a manner as described in FIG. 3A or hardware (decoded by USB display device 170, as shown in FIG. 3B). For the same reason, in the display systems 200A and 200B, the present invention can also decode the video stream without the second core 212A/212B of the processor 210A/210B (ie, the graphics processor) or its first driver 262A/262B. . In the above case, the components used by the display system 100 and the 200A/200B to play the content protected video content through the USB display device are similar. Those skilled in the art of the invention will appreciate that the present invention may also select the conventional mode through the graphics processor 120 or its first driver 162 (or the second core 212A/212B of the processor 210A/210B and its first driver). 262A/262B) Decoding the video stream to obtain video data, and the graphics processor 120 transmits the analog display interface (the resolution is reduced for video content with high image resolution with content protection) or the digital display interface. Play video data on the display.

Figure 4 is a flow chart showing a display method for the display system 100 in accordance with the first embodiment of the present invention. Please also refer to Figure 1, Figure 3A and Figure 4. In step S410, the processor 110 decrypts the first encrypted video stream, which is one of the first encryption and decryption standards (for example, the AACS Advanced Access Content System encryption and decryption standard), to obtain a first video stream (for example, a H.264 video stream). And encrypting the first video stream with a second encryption and decryption standard (such as AES advanced encryption and decryption standard) to obtain a second encrypted video stream. In step S420, the processor 110 executes the second driver 163 to decrypt the second encrypted video stream to obtain a second video stream (for example, an H.264 video stream), and solves the second video stream. Code to get a first video material. In step S430, the processor 110 executes the second driver 163 to encrypt the first video data to obtain an encrypted video data, and transmits the encrypted video data to the USB display device 170. In step S440, the USB display device 170 decrypts the received encrypted video material to obtain a second video material. In step S450, the USB display device 170 plays a decrypted second video material on a display.

Figure 5 is a flow chart showing a display method for the display system 200 in accordance with another embodiment of the present invention. Please also refer to Figure 1, Figure 3B and Figure 5. In step S510, the processor 110 decrypts the first encrypted video stream in a first encryption and decryption standard (for example, the AACS Advanced Access Content System encryption and decryption standard) to obtain a first video stream (for example, an H.264 video stream). And encrypting the first video stream with a second encryption and decryption standard (such as AES advanced encryption and decryption standard) to obtain a second encrypted video stream. In step S520, the processor 110 executes the second driver 163 to obtain the second encrypted video stream, and transmits the second encrypted video stream to the USB display device 170. In step S530, the USB display device 170 decrypts the second encrypted video stream to obtain a second video stream. In step S540, the USB display device 170 decodes the second video stream to obtain a video material. In step S550, the USB display device 170 plays the decoded video data on a display.

It should be noted that the flow of the display methods of FIGS. 4 and 5 only describes how the display system 100 (note: the display system 200A/200B is similar) plays video content with content protection through the USB display device. The data path of the unprotected video stream or the original video data in the display systems 100 and 200A/200B has been disclosed in the foregoing embodiments, and details are not described herein.

The present invention has been disclosed in the above preferred embodiments, and is not intended to limit the scope of the present invention. Any one of ordinary skill in the art can make a few changes without departing from the spirit and scope of the invention. The scope of protection of the present invention is therefore defined by the scope of the appended claims.

100, 200A, 200B‧‧‧ display system

110, 210A, 210B‧‧‧ processor

120, 220B‧‧‧ graphics processor

130, 230A‧‧‧ chipsets

131, 231A‧‧‧ Northbridge

132, 232A‧‧‧ South Bridge Wafer

133‧‧‧Internal busbar

140‧‧‧First memory unit

150‧‧‧Second memory unit

160, 260A, 260B‧‧‧ storage unit

161, 261A, 261B‧‧‧ operating system

162, 262A, 262B‧‧‧ first driver

163, 263A, 263B‧‧‧ second driver

164, 264A, 264B‧‧‧ media files

170, 270A, 270B‧‧‧ USB display device

180‧‧‧External CD player

211A, 211B‧‧‧ first core

212A, 212B‧‧‧ second core

213B‧‧‧ integrated memory controller

240A, 240B, 250B‧‧‧ memory unit

290‧‧‧ Platform Control Hub

310A-350A, 310B-350B‧‧‧ Stage

1 is a functional block diagram of a display system 100 in accordance with an embodiment of the present invention.

2A is a functional block diagram showing a display system 200 in accordance with another embodiment of the present invention.

2B is a functional block diagram of a display system 200 in accordance with yet another embodiment of the present invention.

Figure 3A is a schematic diagram showing the software/hardware architecture of display system 100 in accordance with a first embodiment of the present invention.

Figure 3B is a schematic diagram showing the software/hardware architecture of display system 100 in accordance with a second embodiment of the present invention.

Figure 4 is a flow chart showing a display method for the display system 100 in accordance with the first embodiment of the present invention.

Figure 5 is a flow chart showing a display method for the display system 100 in accordance with a second embodiment of the present invention.

100‧‧‧Display system

110‧‧‧ processor

120‧‧‧graphic processor

130‧‧‧ chipsets

131‧‧‧ North Bridge Chip

132‧‧‧South Bridge Chip

133‧‧‧Internal busbar

140‧‧‧First memory unit

150‧‧‧Second memory unit

160‧‧‧storage unit

161‧‧‧ operating system

162‧‧‧First driver

163‧‧‧Second driver

164‧‧‧Media files

170‧‧‧USB display device

180‧‧‧External CD player

Claims (10)

A display system includes: a processor for decrypting a first encrypted video stream by a first encryption and decryption standard to obtain a first video stream, and using the second encryption and decryption standard for the first video stream Encrypting to obtain a second encrypted video stream; a USB display device; a storage unit including a driver of the USB display device; and a chipset coupled to the processor, the USB display device, and the storage unit; The processor executes the driver to decrypt the second encrypted video stream to obtain a second video stream, and decodes the second video stream to obtain a first video data; wherein the processor further obtains The video data is encrypted to obtain an encrypted video data, and the encrypted video data is transmitted to the USB display device; wherein the USB display device decrypts the encrypted video data to obtain a second video data, and The display plays the second video material. A display method for a display system, the display system comprising: a processor, a USB display device, a storage unit, and a chip set, wherein the storage unit includes a driver of the USB display device, and the chip set The method is coupled to the processor, the USB display device, and the storage unit, the method comprising: decrypting, by the processor, a first encrypted video stream of a first encryption and decryption standard to obtain a first video stream, and a second encryption and decryption standard The first video stream is encrypted to obtain a second encrypted video stream; the processor is used to execute the driver to decrypt the second encrypted video stream to obtain a second video stream, and decode the second video stream to obtain a second video stream. First video data; using the processor to encrypt the obtained video data to obtain an encrypted video data, and transmitting the encrypted video data to the USB display device; and decrypting the encrypted video data by using the USB display device Obtaining a second video data; and playing the decrypted second video data on a display by using the USB display device. A display system includes: a processor for decrypting a first encrypted video stream by a first encryption and decryption standard to obtain a first video stream, and using the second encryption and decryption standard for the first video stream Encrypting to obtain a second encrypted video stream; a USB display device; a storage unit including a driver of the USB display device; and a platform control hub coupled to the processor, the USB display device, and the storage unit The processor executes the driver to decrypt the second encrypted video stream to obtain a second video stream, and decodes the second video stream to obtain a first video data; wherein the processor further Obtaining the obtained video data to obtain an encrypted video data, and transmitting the encrypted video data to the USB display The USB display device decrypts the encrypted video data to obtain a second video data, and plays the second video data on a display. The display system of claim 3, further comprising: a memory unit, wherein the processing unit further comprises a first core, a second core, and an integrated memory controller, the integrated memory controller The memory unit is electrically connected to the first core and the second core to control data access of the memory unit, wherein the first video stream is stored in the memory unit. The display system of claim 4, wherein the first video data obtained by decrypting the second video stream is stored in the memory unit. A display system includes: a processor for decrypting a first encrypted video stream by a first encryption and decryption standard to obtain a first video stream, and using the second encryption and decryption standard for the first video stream Encrypting to obtain a second encrypted video stream; a USB display device; a storage unit including a driver of the USB display device; and a chipset coupled to the processor, the USB display device, and the storage unit; The processor is configured to execute the driver to transmit the second encrypted video stream to the USB display device; wherein the USB display device decrypts the second encrypted video stream to obtain a second video stream, and the Two video streams are decoded to obtain one Video data; wherein the USB display device plays the decoded video data on a display. A display method for a display system, the display system comprising: a processor, a USB display device, a storage unit, and a chip set, wherein the storage unit includes a driver of the USB display device, and the chip set The method is coupled to the processor, the USB display device, and the storage unit, the method comprising: decrypting, by the processor, a first encrypted video stream of a first encryption and decryption standard to obtain a first video stream, and Encrypting the first video stream with a second encryption and decryption standard to obtain a second encrypted video stream; using the processor to execute the driver to transmit the second encrypted video stream to the USB display device; using the USB display device Decrypting the second encrypted video stream from the processor to obtain a second video stream; decoding the decrypted second video stream by the USB display device to obtain a video data; and utilizing the USB display device The video material is played on a display. A display system includes: a processor for decrypting a first encrypted video stream by a first encryption and decryption standard to obtain a first video stream, and using the second encryption and decryption standard for the first video stream Encrypting to obtain a second encrypted video stream; a USB display device; a storage unit including a driver of the USB display device; a platform control hub coupled to the processor, the USB display device, and the storage unit; wherein the processor executes the driver to transmit the second encrypted video stream to the USB display device; wherein the USB display device is The second encrypted video stream is decrypted to obtain a second video stream, and the second video stream is decoded to obtain a video data. The USB display device further plays the decoded video data on a display. The display system of claim 8, further comprising: a memory unit, wherein the processing unit further comprises a first core, a second core, and an integrated memory controller, the integrated memory controller The memory unit is electrically connected to the first core and the second core to control data access of the memory unit, wherein the first video stream is stored in the memory unit. The display system of claim 9, wherein the first video data obtained by decrypting the second video stream is stored in the memory unit.