Content acquisition processing device, content distribution system, content acquisition processing method, and its program

A content distribution method for distributing a content, the method comprising:

• using a plurality of content distribution devices that distribute a content based on a distribution request information that requests distribution of a predetermined content, a content acquisition processing device that is connected to the plurality of content distribution devices and acquires, via a network, a content distributed by the content distribution device based on the distribution request information, and an alternative distribution device connected to the content acquisition processing device via the network and capable of distributing to the content acquisition processing device a content adapted for distribution by the plurality of content distribution devices, wherein
• the alternative distribution device
• transmits to the content acquisition processing device a subscription transmittance request information that requests transmittance of a subscription information regarding whether or not the content distribution device distributes the content to be subscribed, the subscription information being defined for each content distribution device,
• acquires the subscription information transmitted in response to the subscription transmittance request information,
• determines whether or not the content adapted for distribution by the content distribution device defined by the subscription information having been acquired is stored in the content storage,
• when the storing state determiner determines that the content adapted for distribution is stored, transmits to the content acquisition processing device the subscription information updated so that the alternative distribution device is defined as the content distribution device that distributes the content to be subscribed, and
• distributes the content to the content acquisition processing device in response to the distribution request information transmitted from the content distribution processing device, and
• the content acquisition processing device
• transmits the subscription information when having the subscription transmittance request information from the alternative distribution device, wherein the alternative distribution device
• transmits to the content acquisition processing device a subscription transmittance request information that requests transmittance of a subscription information regarding whether or not the content distribution device distributes the content to be subscribed, the subscription information being defined for each content distribution device,
• acquires the subscription information transmitted in response to the subscription transmittance request information,
• determines whether or not the content adapted for distribution by the content distribution device defined by the subscription information having been acquired is stored in the content storage,
• when the storing state determiner determines that the content adapted for distribution is stored, transmits to the content acquisition processing device the subscription information updated so that the alternative distribution device is defined as the content distribution device that distributes the content to be subscribed, and
• distributes the content to the content acquisition processing device in response to the distribution request information transmitted from the content distribution processing device, and
• the content acquisition processing device
• transmits the subscription information when having acquired the subscription transmittance request information from the alternative distribution device,
• acquires from the alternative distribution device the subscription information having been updated,
• specifies alternative distribution device as a subscribed distribution device based on the subscription information having been updated,
• recognizes a difference between the content adapted for distribution and having been updated and the content having been acquired in advance, and
• transmits the distribution request information that requests distribution of the content corresponding to the difference between the content updated for distribution by the alternative distribution device and the content having been acquired in advance to the alternative distribution device.