Abstract:
A HDMI standard multimedia system includes a source device, a plurality of TVs, and a CEC right arbiter. The CEC right arbiter transfers the right of CEC to an appropriate TV of the plurality of TVs according to each status of the plurality of TVs.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a multi-media system and method thereof, and more particularly, to a multi-media system with CEC right transferring mechanism and method thereof. 
         [0003]    2. Description of the Prior Art 
         [0004]    Reference is made to  FIG. 1  for a diagram illustrating a high-definition multimedia interface (HDMI) connector. As depicted in  FIG. 1 , Pin  13  is used for transmitting a consumer electronics control (CEC) signal. Via Pin  13  of an HDMI, a user can control an HDMI standard DVD player for performing operations such as “Play”, “Fast-forward” and “Rewind”, or an HDMI standard set top box (STB) for switching channels, etc. 
         [0005]    Reference is made to  FIG. 2  for a table illustrating the definition of logical address (LA) according to HDMI standard. As depicted in  FIG. 2 , LA “0” is used by TVs, LAs “1”, “2” and “9” are used by recording devices (such as DVD recorders), LAs “3”, “6”, “7” and “10” are used by tuners, LAs “4”, “8” and “11” are used by playback devices (such as DVD players), LA “5” is used by stereos. Meanwhile, Las “12” and “13” are reserved for other undefined devices. LA “14” is used by TVs having physical address (PA) not equal to “0000”. LA “15” is unregistered or for broadcast. 
         [0006]    Reference is made to  FIG. 3  for a diagram illustrating a prior art multi-media system  100 . As depicted in  FIG. 3 , the multi-media system  100  includes a DVD player  111 , an STB  112 , a surveillance camera  113 , a switch  120 , and a TV  131 . The DVD player  111 , the STB  112 , and the surveillance camera  113  can be viewed as source devices of the system, while the TV  131  can be viewed as a sink device or a root device of the system. Each device connected to an HDMI has an LA and a PA. For a source device (TV  131 ), the LA is set to “0” and the PA is set to “0000”. 
         [0007]    Also, the switch  120  can couple the HDMI Pin  13  (CEC) of all source devices (DVD player  111 , STB  112 , surveillance camera  113 ) to that of the sink device (TV  131 ). The switch  120  of the prior art multi-media system  100  is used for enhancing signal strength of source devices only. 
         [0008]    Each source device includes a CEC controller coupled to its own HDMI Pin  13  for receiving a control command from the sink device (TV  131 ), and is thereby capable of performing corresponding operations. For instance, the CEC controller  1111  of the DVD player  111  id coupled to its own HDMI Pin  13 . Based on a control command S CEC  received from the sink device (TV  131 ), the DVD player  111  can perform operations such as “Play”, “Fast-forward” and “Rewind”. 
         [0009]    The sink device (TV  131 ) also includes a CEC controller  1311  coupled to its own HDMI Pin  13  for directly transmitting or broadcasting the control command S CEC  to each device connected to the HDMI based on a target device. Upon receiving and verifying the control command S CEC , the target device performs corresponding operations. For example, if the TV  131  sends the control command S CEC  to LA “4”, then the DVD player  111  performs corresponding operations such as “Play”, “Fast-forward” and “Rewind” 
         [0010]    Reference is made to  FIG. 4  for a diagram illustrating a prior art multi-media system  200 . Though having similar features, the multi-media system  200  differs from the multi-media system  100  in the number of sink devices. As depicted in  FIG. 4 , the multi-media system  200  includes 3 sink devices TVs  131 - 133 , which are respectively coupled to the ports P 1 -P 3  of the switch  120 . Since in all sink devices the LA is set to “0” and the PA is set to “0000”, a source device is unable to determine which sink device has sent the control command S CEC , thereby resulting in system confusion. In the prior art, the sink device (TV  131 ) coupled to the port P 1  of the switch  120  is granted the right of sending the control command S CEC . All source devices can then function according to the control command S CEC  Sent by the TV  131 , thereby avoiding system confusion. 
         [0011]    However, prior art multi-media system may cause inconvenience to users since the sink devices TVs  132  and  133  respectively coupled to the ports P 2  and P 3  of the switch  120  can not be used for controlling a source device. For example, according to user arrangement, the TV  131  is disposed in the living room, the TV  132  is disposed in the bedroom, and the TV  133  is disposed in the bathroom. When the user is in the living room watching TV, the TV  131  is in active mode and can be used for controlling each source device. When the user enters the bedroom or the bathroom and leaves the living room, the TV  131  enters standby mode. Under this circumstance, the TVs  132  and  133  can not be used for controlling each source device. 
       SUMMARY OF THE INVENTION 
       [0012]    The present invention provides a multi-media system with CEC right transferring mechanism, comprising a source device having an HDMI for performing operations based on a CEC command; a first sink device having an HDMI and comprising a memory device for storing a first identification data and a CEC controller for receiving a second identification data and thereby enabling the first sink device to transmit the CEC command based on the first and second identification data; a second sink device having an HDMI and comprising a memory device for storing a third identification data and a CEC controller for receiving the second identification data and thereby enabling the second sink device to transmit the CEC command based on the third and second identification data; and a switch having an HDMI and coupled between the source device, the first sink device and the second sink device comprising a first port coupled to the first sink device; a second port coupled to the second sink device; and a CEC right arbiter coupled between the first and second ports for respectively transmitting the first and third identification data to the first and second sink devices and for transmitting the second identification data based on status of the first and second sink devices during initialization. 
         [0013]    The present invention provides a multi-media system with CEC right transferring mechanism, comprising a source device having an HDMI for performing operations based on a CEC command; a first sink device having an HDMI and comprising a memory device for storing a first identification data and a CEC controller for receiving a second identification data and thereby enabling the first sink device to transmit the CEC command based on the first and second identification data; a second sink device having an HDMI and comprising a CEC controller for transmitting the CEC command; and a switch having an HDMI and coupled between the source device, the first sink device and the second sink device, and comprising a first port coupled to the first sink device, a second port coupled to the second sink device, and a CEC right arbiter coupled between the first and second ports for transmitting the first identification data to the first sink device and for transmitting the second identification data based on status of the first sink device during initialization. 
         [0014]    The present invention provides a multi-media system with CEC right transferring mechanism comprising a source device having an HDMI for performing operations based on a CEC command; a first sink device having an HDMI and comprising a CEC controller for transmitting the CEC command; a second sink device having an HDMI and comprising a CEC controller for transmitting the CEC command; and a switch having an HDMI and coupled between the source device, the first sink device and the second sink device, and comprising a first port coupled to the first sink device, a second port coupled to the second sink device, and a CEC right arbiter coupled between the first and second ports for transmitting the CEC command transmitted from the first sink device or from the second sink device to the source device based on a setting. 
         [0015]    These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  is a diagram illustrating an HDMI connector 
           [0017]      FIG. 2  is a table illustrating the definition of logical address according to HDMI standard. 
           [0018]      FIG. 3  is a diagram illustrating a prior art multi-media system. 
           [0019]      FIG. 4  is a diagram illustrating another prior art multi-media system. 
           [0020]      FIG. 5  is a diagram illustrating a multi-media system with CEC right transferring mechanism according to a first embodiment of the present invention. 
           [0021]      FIG. 6  is a diagram illustrating a multi-media system when performing CEC right transfer according to the present invention. 
           [0022]      FIG. 7  is a diagram illustrating another multi-media system when performing CEC right transfer according to the present invention. 
           [0023]      FIG. 8  is a flowchart illustrating a method for controlling a multi-media system with CEC right transferring mechanism. 
           [0024]      FIG. 9  is a flowchart illustrating another method for controlling a multi-media system with CEC right transferring mechanism. 
       
    
    
     DETAILED DESCRIPTION 
       [0025]    Reference is made to  FIG. 5  for a diagram illustrating a multi-media system  500  with CEC right transferring mechanism according to a first embodiment of the present invention. As depicted in  FIG. 5 , the multi-media system  500  includes the DVD player  111 , the STB  112 , the surveillance camera  113 , a switch  520 , and TVs  531 - 533 . The DVD player  111 , the STB  112 , and the surveillance camera  113  can be viewed as source devices of the system, while the TVs  531 - 533  can be viewed as sink devices or root devices of the system. Each device connected to an HDMI has an LA and a PA. For sink devices (TVs  531 - 533 ), the LA is set to “0” and the PA is set to “0000”. 
         [0026]    In addition to enhancing signal strength of the source devices, the switch  520  of the present invention further includes a CEC right arbiter  521 . The HDMI Pin  13  (CEC) of all source devices (DVD player  111 , STB  112 , surveillance camera  113 ) can be coupled to those of the sink devices (TVs  531 - 533 ) respectively and to the CEC right arbiter  521 . 
         [0027]    The source devices, the DVD player  111 , the STB  112 , and the surveillance camera  113 , respectively include CEC controllers  1111 ,  1121  and  1131  coupled to corresponding HDMI Pins  13  for receiving a control command from the sink devices (TVs  531 - 533 ), and are thereby capable of performing corresponding operations. For instance, the CEC controller  1111  of the DVD player  111  is coupled to its own HDMI Pin  13 . Based on the control command S CEC  received from the sink devices (TVs  531 - 533 ), the DVD player  111  can perform operations such as “Play”, “Fast-forward” and “Rewind”. 
         [0028]    Meanwhile, the TVs  531 ,  532  and  533  also respectively include CEC controllers  5311 ,  5321  and  5331  coupled to corresponding HDMI Pins  13  for directly sending or broadcasting a control command S CEC  to all devices connected to the HDMI based on a target source device. For example, if the TV  531  sends a control command S CEC  having LA set to “4”, the DVD player  111  then performs corresponding operations such as “Play”, “Fast-forward” and “Rewind”. 
         [0029]    The TVs  531 ,  532  and  533  further include memory devices  5312 ,  5322  and  5332  for storing respective identification data. The memory devices  5312 ,  5322  and  5332  can include random access memory (RAM). 
         [0030]    During initialization when identification data has not been stored in the TVs  531 - 533 , the CEC right arbiter  521  is used for providing the TVs  531 - 533  with identification data. Based on the ports P 1 -P 3  to which the TVs  531 - 533  are respectively connected, the CEC right arbiter  521  respectively provides the TVs  531 - 533  with identification data ID 1 -ID 3 , which is respectively stored in the memory devices  5312 ,  5322  and  5332 . 
         [0031]    After respectively bestowing the identification data ID 1 -ID 3  on the TVs  531 - 533 , the CEC right arbiter  521  can grant the CEC right to the TV  531  with the identification data ID 1 . To be more precise, when the TVs  531 - 533  are all in active mode, the CEC right arbiter  521  makes a broadcast to the TVs  531 - 533 , thereby informing that the CEC right is currently owned by a device having the identification data ID 1 . The CEC controllers  5311 ,  5321  and  5331  of the TVs  531 ,  532  and  533  can then compare the identification data broadcast by the CEC right arbiter  521 with those stored in the  5312 ,  5322  and  5332 , respectively. For instance, if the identification data ID 1  is associated with the CEC right in the broadcast made by the CEC right arbiter  521 , only the CEC controller  5311  can locate a matched identification data stored in the memory device  5312 . As a result, the TV  531  can send the CEC command S CEC  via the CEC controller  5311 , thereby controlling each source device for performing corresponding operations. 
         [0032]    Upon entering standby mode, the TV  531  informs the CEC right arbiter  521  via the CEC controller  5311  and releases the CEC right, which can then be granted to the TV  532  having the identification data ID 2  or the TV  533  having the identification data ID 3 , depending on user request. To be more precise, after the TV  531  enters standby mode and releases the CEC right, the CEC right arbiter  521  makes another broadcast to the TVs  531 - 533 , thereby informing that the CEC right is currently owned by a device having the identification data ID 2  or ID 3 . For instance, if the identification data ID 2  is associated with the CEC right in the broadcast made by the CEC right arbiter  521 , only the CEC controller  5321  can locate a matched identification data stored in the memory device  5322 . As a result, the TV  532  can send the CEC command S CEC  via the CEC controller  5321 , thereby controlling each source device for performing corresponding operations. 
         [0033]    Reference is made to  FIG. 6  for a diagram illustrating the multi-media system  500  after the TV  531  enters standby mode and releases the CEC right. As depicted in  FIG. 6 , when the TV  531  is in standby mode, the CEC right arbiter  521  gives the CEC right to the TV  532  having the identification data ID 2 . As a result, the TV  532  can control each source device for performing corresponding operations by sending the CEC command S CEC . 
         [0034]    In the multi-media system  500 , all of the TVs  531 - 533  must be able to transfer the CEC right based on the CEC command S CEC  sent by the CEC right arbiter  521 . Supposed one of the TVs  531 - 533  (assuming the TV  531 ) does not support such function when the CEC right arbiter  521  requests a CEC right transfer from the TV  531  to the TV  533 , the TV  531  may continue to possess the CEC right, thereby causing system confusion. 
         [0035]    Reference is made to  FIG. 7  for a diagram illustrating a multi-media system  700  with CEC right transferring mechanism according to a second embodiment of the present invention. As depicted in  FIG. 7 , the multi-media system  700  includes the DVD player  111 , the STB  112 , the surveillance camera  113 , a switch  720 , and the TVs  531 - 533 . The DVD player  111 , the STB  112 , and the surveillance camera  113  can be viewed as source devices of the system, while the TVs  531 - 533  can be viewed as sink devices or root devices of the system. Each device connected to an HDMI has an LA and a PA. For sink devices (TVs  531 - 533 ), the LA is set to “0” and the PA is set to “0000”. In addition to enhancing signal strength of the source devices, the switch  720  of the present invention further includes a CEC right arbiter  721 . Similar features between the multi-media systems and  500  and  700  will not described again. The multi-media system  700  differs from the multi-media system  500  in that the HDMI Pins  13  (CEC) of the source devices (DVD player  111 , STB  112 , surveillance camera  113 ) are short-circuited first before being coupled to the CEC right arbiter  721 , while the HDMI Pins  13  (CEC) of the TVs  531 - 533  are respectively coupled to the CEC right arbiter  721 . As a result, the multi-media system  700  can avoid system confusion if the TVs  531 - 533  are not capable of transferring CEC right. In addition, if the TV  531  is not capable of transferring CEC right, the memory device  5312  is not necessary since there is no need to store the identification data sent from the CEC right arbiter  721 . 
         [0036]    Reference is made to  FIG. 8  for a method  800  for controlling the multi-media system  700  with CEC right transferring mechanism. In the method  800 , the TVs  531  and  532  can perform CEC right transfer, while the TV  533  is incapable of such function.  FIG. 8  includes the following steps: 
         [0037]    Step  801 : the CEC right arbiter  721  transmits identification data to each of the TVs  531 - 533 ; 
         [0038]    Step  802 : the TVs  531  and  532  store corresponding identification data and reply with confirmed identification data so that the CEC right arbiter  721  can be informed of the ability to transfer CEC right; 
         [0039]    Step  803 : the TV  533  does not store corresponding identification data nor reply with confirmed identification data so that the CEC right arbiter  721  can be informed of the inability to transfer CEC right; 
         [0040]    Step  804 : the CEC right arbiter  721  performs CEC right transfer on the TVs  531  and  532 ; 
         [0041]    Step  805 : the CEC right arbiter  721  ignores the CEC command sent by the TV  533 ; 
         [0042]    Step  806 : the CEC right arbiter  721  transfers the CEC right to the TV  533  when both the TVs  531  and  532  are in standby mode. 
         [0043]    In the method  800 , the CEC right arbiter  721  first transmits corresponding identification data to each of the TVs  531 - 533 . For a TV capable of performing CEC right transfer, the received identification data is stored and a confirmed identification data is replied for informing the CEC right arbiter  721  of its CEC right transferring ability. On the other hand, a TV incapable of performing CEC right transfer does not store the received identification data nor replied with a confirmed identification data. Under this circumstance, the CEC right arbiter  721  can be informed of its inability to transfer CEC right. In step  806 , the CEC right arbiter  721  sends the CEC command S CEC  received from the TV  533  directly to the source device for performing corresponding operations. 
         [0044]    In addition, the CEC right arbiter  721  can isolate the CEC pins of the source devices from those of the sink devices. Therefore, a sink device with CEC right transferring and a sink device without CEC right transferring can avoid interfering each other. 
         [0045]    Reference is made to  FIG. 9  for a method  900  for controlling the multi-media system  700  with CEC right transferring mechanism. In the method  900 , all of the TVs  531 - 533  are unable to perform CEC right transfer.  FIG. 9  includes the following steps: 
         [0046]    Step  901 : the CEC right arbiter  721  transmits identification data to each of the TVs  531 - 533 ; 
         [0047]    Step  902 : the TVs  531 - 533  do not store corresponding identification data nor reply with confirmed identification data so that the CEC right arbiter  721  can be informed of the inability to transfer CEC right; 
         [0048]    Step  903 : the CEC right arbiter  721  authorizes the CEC right to one of the TVs  531 - 533  based on user request; 
         [0049]    Step  904 : the CEC right arbiter  721  ignores the CEC command sent by other TVs not having the CEC right; 
         [0050]    Step  905 : the CEC right arbiter  721  transfers the CEC right to another TV in active mode when the original TV authorized with the CEC right enters standby mode. 
         [0051]    In the method  900 , the CEC right arbiter  721  can isolate the CEC pins of the source devices from those of the sink devices. Therefore, a sink device with CEC right transferring and a sink device without CEC right transferring can avoid interfering each other. In steps  904  and  905 , the CEC right arbiter  721  selectively transmits to CEC command S CEC  to the source devices. 
         [0052]    CEC right can by dynamically switched in the multi-media systems according to the present invention. For example, when watching TV in the living room, the user can control each source device via the TV in the living room. When the user leaves the living room and enters the bedroom, the TV in the living room enters standby mode and releases the CEC right to the TV in the bedroom. Therefore, the user can also control each source device via the TV in the bedroom. The present invention can thus provide users with more flexibility and convenience. 
         [0053]    Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention.