Transmission apparatus and transmission method

摘要

A request message containing a first description defining a portion to be extracted from multimedia data and a second description defining a scheme for extracting the portion is received from a data reception apparatus. The portion defined by the first description is extracted as partial data from the multimedia data. A coefficient corresponding to the scheme defined by the second description is acquired. Whether a value corresponding to the acquired coefficient is larger than a threshold is determined. If the value is larger than the threshold, the partial data is compressed, and compressed data obtained by the compression is transmitted to the data reception apparatus. If the value is equal to or smaller than the threshold, the partial data is transmitted to the data reception apparatus.

主权项

1. A transmission apparatus for transmitting data requested by an external apparatus to the external apparatus, comprising:
a holding unit which holds, for each splitting scheme of extracting partial data from multimedia data, information indicating compression validness for data to be extracted by the splitting scheme; a reception unit which receives, from the external apparatus, a request message containing a first description defining a portion to be extracted from the multimedia data, and a second description defining a splitting scheme of extracting the portion; an extraction unit which extracts, from the multimedia data, the portion defined by the first description as partial data according to the splitting scheme defined by the second description contained in the request message; an acquisition unit which acquires, from said holding unit, the information corresponding to the splitting scheme defined by the second description; a determination unit which, on the basis of the information acquired by said acquisition unit, determines whether compression of the extracted partial data is valid; and a transmission unit which controls whether to compress the partial data in accordance with a determination result of said determination unit , and transmits one of the compressed partial data and uncompressed partial data obtained by the control to the external apparatus, wherein the splitting scheme defined by the second description contained in the request message is any one of a temporal splitting scheme for extracting a portion defined by a designated begin time and end time from the multimedia data being a movie, a spatial splitting scheme for extracting a region defined by designated coordinates and range from the multimedia data being the movie, and a track splitting scheme for extracting a subtitle track portion from the multimedia data being the movie, and wherein said determination unit determines that compression of the extracted partial data is valid, when the splitting scheme defined by the second description contained in the request message is the track splitting scheme.