Patent Publication Number: US-2021185291-A1

Title: Video interface conversion device and method

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present disclosure relates to a video interface conversion device and a video interface conversion method. 
     2. Description of Related Art 
     Consumer electronics products may use different display interfaces due to different market needs or may use the same display interface that supports different bandwidth or different transmission rates due to variations of technical versions or product specifications. As a result, conversions between different interfaces or different bandwidths are required. By using an interface or bandwidth conversion device, the user is able to obtain a better viewing experience throughout different types of consumer electronics products. 
     Even though many interface conversion products exist, difference in bandwidth limits between the input interface and the output interface can degrade the viewing experience. 
     SUMMARY OF THE INVENTION 
     In consideration of the problem of the prior art, an object of the present disclosure is to provide a video interface conversion device and a video interface conversion method. 
     The present disclosure discloses a video interface conversion device that includes a first interface transmission circuit, a second interface transmission circuit, a color conversion circuit and an image compression circuit. The first interface transmission circuit is electrically coupled to an image source. The second interface transmission circuit is electrically coupled to a display terminal to negotiate a maximum output bandwidth with the display terminal such that the first interface transmission circuit compares an input data bandwidth of a data signal received from the image source and the maximum output bandwidth. When the maximum output bandwidth is smaller than the input data bandwidth, the image compression circuit is configured to perform image compression on the data signal and/or the color conversion circuit is configured to perform color coding conversion on the data signal so that the processed data signal has the input data bandwidth being smaller than or equal to the maximum output bandwidth, and wherein the processed data signal is further transmitted by the second interface transmission circuit to the display terminal. 
     The present disclosure also discloses a video interface conversion method used in a video interface conversion device that includes the steps outlined below. By a first interface transmission circuit, an input data bandwidth of a data signal received from an image source and a maximum output bandwidth negotiated by a second interface transmission circuit with a display terminal are compared. Image compression is performed on the data signal by an image compression circuit and/or color coding conversion is performed on the data signal by a color conversion circuit when the maximum output bandwidth is smaller than the input data bandwidth so that the processed data signal has the input data bandwidth being smaller than or equal to the maximum output bandwidth. The processed data signal is transmitted by the second interface transmission circuit to the display terminal 
     These and other objectives of the present disclosure will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiments that are illustrated in the various figures and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a block diagram of a video interface conversion device according to an embodiment of the present invention. 
         FIG. 2  illustrates a detail block diagram of the video interface conversion device according to an embodiment of the present invention. 
         FIG. 3  illustrates a flow chart of a video interface conversion method according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     An aspect of the present invention is to provide a video interface conversion device and a video interface conversion method to coordinate an input data bandwidth and a maximum output bandwidth to accomplish the most efficient data transmission and the best display result at the same time. 
     Reference is now made to  FIG. 1 .  FIG. 1  illustrates a block diagram of a video interface conversion device  100 , an image source VS and a display terminal DT according to an embodiment of the present invention. 
     The video interface conversion device  100  is electrically coupled between the image source VS and the display terminal DT. The image source VS can be such as, but not limited to a notebook computer or a handheld electronic device. The display terminal DT can be such as, but not limited to a television. The image source VS is configured to provide a data signal DS such that the video interface conversion device  100  amends the data amount of the data signal DS and/or converts the format of the data signal DS to generate a data signal DS′. The video interface conversion device  100  further transmits the data signal DS′ to the display terminal DT to be displayed. 
     More specifically, when the image source VS and the display terminal DT have the same video interface format but with different data input and output bandwidths, the video interface conversion device  100  is configured to coordinate the data input and output bandwidths such that the data signal DS from the image source VS is amended to generate the data signal DS′ suitable to be displayed by the display terminal DT. The data signal DS′ can thus be displayed by the display terminal DT. 
     On the other hand, when the image source VS and the display terminal DT have different video interface formats and different data input and output bandwidths, the video interface conversion device  100  not only coordinates the data input and output bandwidths, but also performs conversion of the video interfaces such that the data signal DS can be transmitted from the image source VS to the display terminal DT. In an embodiment, when the image source VS and the display terminal DT have different video interface formats, one of the image source VS and the display terminal DT may have the video interface format of such as, but not limited to DisplayPort, and the other may have the video interface format of such as, but not limited to High Definition Multimedia Interface (HDMI). 
     Reference is now made to  FIG. 2 .  FIG. 2  is a detail block diagram of the video interface conversion device  100  according to an embodiment of the present invention. 
     The video interface conversion device  100  includes a first interface transmission circuit  110 , a second interface transmission circuit  120 , an image decompression circuit  130 , a color conversion circuit  140  and an image compression circuit  150 . 
     The first interface transmission circuit  110  is electrically coupled to the image source VS. The second interface transmission circuit  120  is electrically coupled to the display terminal DT. 
     The image decompression circuit  130 , the color conversion circuit  140  and the image compression circuit  150  are configured to perform conversion of data amount on the data signal DS received by the first interface transmission circuit  110  from the image source VS. 
     The image decompression circuit  130  and the image compression circuit  150  are configured to decompress and compress the data signal DS to accomplish the object of conversion of data amount. 
     The color conversion circuit  140  is configured to perform color coding conversion on the data signal DS that uses different color coding or abandons part of the color information to accomplish the object of conversion of data amount. In an embodiment, the data signal DS can be transmitted to the color conversion circuit  140  directly from the first interface transmission circuit  110  to perform color coding conversion and be outputted to the second interface transmission circuit  120  and further to the display terminal DT. On the other hand, the data signal DS can be transmitted from the first interface transmission circuit  110 , processed by the image decompression circuit  130  and further transmitted to the color conversion circuit  140  to perform color coding conversion. Further, the converted data signal DS can be processed by the image compression circuit  150 , outputted to the second interface transmission circuit  120  and further outputted as the data signal DS′ to the display terminal DT. 
     The operation process of the video interface conversion device is described in detail in the following paragraphs. 
     At first, the first interface transmission circuit  110  is configured to compare an input data bandwidth of the data signal DS received from the image source VS and a maximum output bandwidth negotiated by the second interface transmission circuit  120  with the display terminal DT. 
     In an embodiment, the first interface transmission circuit  110  determines whether the data signal DS is a standard image format. The standard image format can be such as, but not limited to the standard format defined by Video Electronics Standards Association (VESA). 
     When the data signal DS is not the standard image format, the first interface transmission circuit  110  determines that the data signal DS is a compressed format and compares the input data bandwidth of the decompressed data signal DS and the maximum output bandwidth negotiated by the second interface transmission circuit  120  with the display terminal DT. The first interface transmission circuit  110  can selectively control the image decompression circuit  130  to perform decompression on the data signal DS when such as, but not limited to the condition that the maximum output bandwidth is larger than the input data bandwidth of the decompressed data signal DS. 
     The maximum output bandwidth negotiated by the second interface transmission circuit  120  with the display terminal DT is the maximum output bandwidth that is set according to the data transmission ability and display ability supported by the display terminal DT after the second interface transmission circuit  120  is connected to the display terminal DT. 
     In an embodiment, the display terminal DT may store display terminal identification information (not illustrated), such as but not limited to extended display identification data (EDID) or DisplayPort configuration data (DPCD), used to identify the data transmission ability and display ability supported by the display terminal DT. The second interface transmission circuit  120  can receive the display terminal identification information to determine the maximum output bandwidth negotiated with the display terminal DT according to the display terminal identification information and transmits the information of the maximum output bandwidth to the first interface transmission circuit  110 . 
     In another embodiment, the second interface transmission circuit  120  and the display terminal DT are coupled through a wire WL. The second interface transmission circuit  120  determines the maximum output bandwidth negotiated with the display terminal DT according to both the display terminal identification information and the wire transmission ability of the wire WL. In practical implementation, the second interface transmission circuit  120  can transmit connection test signals having different output bandwidths and determine the wire transmission ability by determining whether the display terminal DT responses to the connection test signals. As a result, besides the output bandwidths that the display terminal DT can actually support, the second interface transmission circuit  120  can also determine the maximum output bandwidth according to the wire transmission ability to avoid the misjudgment of the maximum output bandwidth due to the low quality of the wire. 
     When the maximum output bandwidth is smaller than the input data bandwidth, the first interface transmission circuit  110  controls the image compression circuit  150  to perform image compression and/or the color conversion circuit  140  to perform color coding conversion on the data signal DS, so that the processed data signal DS has the input data bandwidth being smaller than or equal to the maximum output bandwidth. Further, the data signal DS after being processed is transmitted by the second interface transmission circuit  120  to the display terminal DT to be displayed on the display terminal DT. 
     For example, when the data signal DS is inputted with a high resolution, e.g. a resolution higher than or equal to  4 K, such that the maximum output bandwidth is smaller than the input data bandwidth, the image compression circuit  150  can perform image compression on the data signal DS so that the processed data signal DS has the input data bandwidth being smaller than or equal to the maximum output bandwidth. The data signal DS′ after being compressed can be transmitted by the second interface transmission circuit  120  to the display terminal DT to be displayed on the display terminal DT. 
     On the other hand, the color conversion circuit  140  performs color coding conversion that includes a color format conversion, a color depth coding or a combination thereof on the data signal DS. The color format of the data signal DS can be such as, but not limited to YUV444, YUV422, YUV420 or RGB format of 16-bit, 12-bit, 10-bit or 8-bit. 
     When the maximum output bandwidth is smaller than the input data bandwidth, the color conversion circuit  140  can convert the data signal DS from a color format having a larger data amount to a color format having a relatively smaller data amount so that the processed data signal DS has the input data bandwidth being smaller than or equal to the maximum output bandwidth. The data signal DS′ after the color conversion is performed can be transmitted by the second interface transmission circuit  120  to the display terminal DT to be displayed on the display terminal DT. 
     It is appreciated that the image compression and the color format conversion can be performed selectively or simultaneously to accomplish different degrees of decreasing of the data amount. 
     In yet another embodiment, when the maximum output bandwidth is smaller than the input data bandwidth and the difference therebetween is larger than a predetermine threshold value, besides the decreasing of the data amount by using the image compression and the color format conversion, the component of sound included in the data signal DS can be selectively abandoned to further decrease the data amount so that the data signal DS′ can be transmitted by the second interface transmission circuit  120  to the display terminal DT to be displayed on the display terminal DT. 
     In yet another embodiment, when the image compression formats mismatch under the condition that the maximum output bandwidth is equal to the input data bandwidth, a newly compressed version of the data signal DS can be generated by using the image decompression circuit  130  and the image compression circuit  150  so that the data signal DS′ can be transmitted by the second interface transmission circuit  120  to the display terminal DT to be displayed on the display terminal DT. 
     In yet another embodiment, when the maximum output bandwidth is smaller than the input data bandwidth and the data amount can not be further decreased according to the image compression and the color format conversion performed by the color conversion circuit  140  and the image compression circuit  150  such that the display terminal DT is not able to display the data signal DS′, the condition that the wire transmission ability is too low such that the difference between the maximum output bandwidth and the input data bandwidth is too large is determined. 
     As a result, the second interface transmission circuit  120  amends a supported output bandwidth of display terminal identification information according to the wire transmission ability and transmits the supported output bandwidth to the image source VS through the first interface transmission circuit  110  such that the image source VS amends the input data bandwidth of the data signal DS according to the supported output bandwidth and retransmits the data signal. The difference between the maximum output bandwidth and the input data bandwidth can thus be decreased so that the data signal DS can be directly transmitted by the second interface transmission circuit  120  to the display terminal DT or can be processed by using the image compression or the color format conversion in order to be displayed on the display terminal DT. 
     When the maximum output bandwidth is larger than the input data bandwidth, the second interface transmission circuit  120  can either directly output the data signal DS or can reconnect to the display terminal DT and negotiate an output bandwidth that is larger than or equal to the input data bandwidth and is closest to the input data bandwidth. 
     For example, in a usage scenario, when the first interface transmission circuit  110  determines that the data signal DS is not the standard image format and determines that the maximum output bandwidth is larger than the input data bandwidth, the first interface transmission circuit  110  can control the image decompression circuit  130  to decompress the data signal DS such that the second interface transmission circuit  120  directly outputs the decompressed data signal DS′ to the display terminal DT. Under such a condition, even the input data bandwidth is smaller, the display terminal DT having a better transmission and display ability can accomplish a better display result by using the method described above. 
     When the first interface transmission circuit  110  determines that the data signal DS is the standard image format and determines that the maximum output bandwidth is larger than the input data bandwidth, the second interface transmission circuit  120  can directly output the data signal DS′ without the processing of the image decompression circuit  130 , the color conversion circuit  140  and the image compression circuit  150  such that the data signal DS′ is displayed on the display terminal DT. 
     On the other hand, when the condition such as, but not limited to that the level of the format supported by the image source VS is too low such that the maximum output bandwidth is larger than the input data bandwidth, the second interface transmission circuit  120  can reconnect to the display terminal DT and negotiate a format having a lower bandwidth. More specifically, the second interface transmission circuit  120  can negotiate the output bandwidth with the display terminal DT that is larger than or equal to the input data bandwidth and is closest to the input data bandwidth to avoid the condition that an over-high level of transmission format is used for the transmission toward the display terminal DT when the input data bandwidth of the image source VS is smaller. A power-saving mechanism can thus be accomplished. 
     It is appreciated that when the image source VS and the display terminal DT have the same video interface format, the video interface conversion device  100  can simply perform coordination of the data input and output bandwidth described above. When the image source VS and the display terminal DT have different video interface formats, beside the coordination of the data input and output bandwidth, the video interface conversion device  100  further uses the second interface transmission circuit  120  to perform conversion of the video interface format such that the video interface format of the data signal DS is converted from the format corresponding to the image source VS to the format corresponding to the display terminal DT. 
     As a result, the video interface conversion device  100  can perform coordination when the input data bandwidth of the data signal DS received from the image source VS by the first interface transmission circuit  110  is different from the maximum output bandwidth negotiated by the second interface transmission circuit  120  with the display terminal DT to accomplish the most efficient data transmission and the best display result. 
     Reference is now made to  FIG. 3 .  FIG. 3  is a flow chart of a video interface conversion method  300  according to an embodiment of the present invention. 
     Besides the device described above, the present invention further provides the video interface conversion method  300  that can be used in such as, but not limited to the video interface conversion device  100  in  FIG. 1 . As illustrated in  FIG. 3 , an embodiment of the video interface conversion method  300  includes the following steps. 
     In step S 310 , by the first interface transmission circuit  110 , the input data bandwidth of the data signal DS received from the image source VS and the maximum output bandwidth negotiated by the second interface transmission circuit  120  with the display terminal DT are compared. 
     In step S 320 , image compression is performed by the image compression circuit  150  and/or color coding conversion is performed by the color conversion circuit  140  on the data signal DS when the maximum output bandwidth is smaller than the input data bandwidth so that the data signal DS after processing (data signal DS′) has the input data bandwidth being smaller than or equal to the maximum output bandwidth. 
     In step S 330 , the data signal DS after processing (data signal DS′) is transmitted by the second interface transmission circuit  120  to the display terminal DT. 
     It is appreciated that the embodiments described above are merely an example In other embodiments, it should be appreciated that many modifications and changes may be made by those of ordinary skill in the art without departing, from the spirit of the invention. 
     In summary, the video interface conversion device and the video interface conversion method can perform coordination when the input data bandwidth of the data signal received from the image source by the first interface transmission circuit is different from the maximum output bandwidth negotiated by the second interface transmission circuit with the display terminal to accomplish the most efficient data transmission and the best display result. 
     The aforementioned descriptions represent merely the preferred embodiments of the present disclosure, without any intention to limit the scope of the present disclosure thereto. Various equivalent changes, alterations, or modifications based on the claims of present disclosure are all consequently viewed as being embraced by the scope of the present disclosure.