Media distribution switching method, receiving device and transmitting device

Abstract

A request packet generation unit generates a request packet for requesting the distribution of media information. A request packet transmitting unit transmits the request packet. A request response packet receiving unit receives a request response packet corresponding to the request packet from a transmitting device. A request response analysis unit analyzes a request response set in the request response packet. A mode determination unit switches between an operation mode for real-time transmission and that for non-real-time transmission according to device type information, attached to the request response, indicating whether the transmitting device is for real-time transmission or non-real-time transmission. A first receiving unit receives media information in an operation mode for real-time transmission. A second receiving unit receives media information in an operation mode for non-real-time transmission.

What is claimed is: 
     
       1. A media distribution switching method for switching media information distributed from a transmitting device to a receiving device on a packet network, comprising:
 transmitting a request packet for requesting distributing of the media information from the receiving device to the transmitting device; 
 determining by the transmitting device whether a request mode set in the request packet matches an operation mode of the transmitting device; 
 returning from the transmitting device to the receiving device when the request mode matches the operation mode, a request response packet to which device type information is attached, the device type information indicating whether the transmitting device is for real-time transmission in which a program clock reference is used to perform synchronization between a transmission side and a reception side when a real-time encoder is specified in the request response packet or non-real-time transmission in which flow control is performed to perform synchronization between the transmission side and the reception side when a distribution server is specified in the request response packet; and 
 performing a reception process by switching between an operation mode for real-time transmission and an operation mode for non-real-time transmission in the receiving device, according to device type information attached to the request response packet received from the transmitting device. 
 
     
     
       2. The media distribution switching method according to  claim 1 , wherein
 when transmitting the request packet to the transmitting device, the receiving device attaches distribute request mode information for specifying a first operation mode expected by the receiving device to the request packet, and 
 when the distribute request mode information attached to the request packet coincides with an operation mode of the transmitting device, the transmitting device returns the request response packet to which information indicating normality is attached, and when the distribute request mode information attached to the request packet does not coincide with an operation mode of the transmitting device, the transmitting device returns the request response packet to which information indicating abnormality is attached, and 
 when information indicating normality is attached to the request response packet received from the transmitting device, the receiving device performs a receiving operation in an operation mode corresponding to device type information attached to the request response packet, and 
 when information indicating abnormality is attached to the request response packet received from the transmitting device, the receiving device re-transmits a request packet to which distribute request mode information for specifying an operation mode different from the first operation mode is attached, to the transmitting device. 
 
     
     
       3. A receiving device for receiving media information transmitted from a transmitting device on a packet network, comprising:
 a request packet generation unit configured to generate a request packet in which a request mode is set for requesting distribution of the media information; 
 a request response packet receiving unit configured to receive a request response packet corresponding to the request packet from the transmitting device; 
 a request response analysis unit configured to analyze a request response set in the request response packet; 
 a mode determination unit configured to switch, based on device type information attached to the request response packet, between an operation mode for real-time transmission in which a program clock reference is used to perform synchronization between a transmission side when a real-time encoder is specified in the request response packet and a reception side and an operation mode for non-real-time transmission in which flow control is performed to perform synchronization between the transmission side and the reception side when a distribution server is specified in the request response packet; 
 a first receiving unit configured to receive the media information in an operation mode for non-real-time transmission; and 
 a second receiving unit configured to receive the media information in an operation mode for real-time transmission. 
 
     
     
       4. A transmitting device for transmitting media information to a receiving device on a packet network, comprising:
 a request packet receiving unit configured to receive from the receiving device a request packet for requesting distribution of the media information; 
 a request packet analysis unit configured to determine whether a request mode set in the request packet matches an operation mode of the transmitting device; and 
 a request response packet transmitting unit configured to return, when the request mode matches the operation mode, to the receiving device in response to the request, a request response packet to which device type information is attached, the device type information indicating whether the transmitting device is a real-time transmission in which a program clock reference is used to perform synchronization between a transmission side and a reception side when a real-time encoder is specified in the request response packet or a non-real-time transmission in which flow control is performed to perform synchronization between the transmission side and the reception side when a distribution server is specified in the request response packet.