Coding parameter deriving apparatus, coding parameter deriving method and program
An encoding parameter deriving apparatus for improving video delivery quality is provided. The encoding parameter deriving includes: a relationship deriving unit that calculates a value of an index indicating a quality of experience of a viewer for each of a plurality of encoded videos generated by encoding an original video by a plurality of combinations of values of encoding parameters, and derives a relationship between the values of the encoding parameters and the values of the index; and a possibility deriving unit that derives a plurality of possibilities for a combination of values of the encoding parameters to be used for encoding the original video, based on the relationship.
1. An encoding parameter deriving apparatus comprising:
a processor; and
a memory storing program instructions that cause the processor to:
calculate a value of an index indicating a quality of experience of a viewer for each of a plurality of encoded videos generated by encoding an original video by a plurality of combinations of values of encoding parameters, and derive a relationship between the values of the encoding parameters and the values of the index; and
derive a plurality of possibilities for a combination of values of the encoding parameters to be used for encoding the original video, based on the relationship, wherein the program instructions further cause the processor to
convert time-series data of throughput in a past delivery related to the original video into time-series data of values of the index;
derive values of the index each corresponding to one of the plurality of possibilities based on the time-series data of the values of the index, and
derive the plurality of possibilities based on the derived values of the index and the relationship,
wherein the program instructions further cause the processor to:
convert time-series data of throughput in the past delivery related to the original video into the time-series data of values of the index by substituting bit rate value at each time point of the time-series data of the bit rate that is obtained for each past delivery, for by of expression (1) to calculate a QoE corresponding to the bit rate value, and arranging the obtained QoE at each time point in time series
Q=c 1 /1+ e −c 2 ×log 10 b v +c 3 (1)
wherein c1, c2, and c3 are constants, and by is the bit rate.
2. The encoding parameter deriving apparatus according to claim 1 , wherein the program instructions cause the processor to
derive a distribution of the values of the index based on the time-series data of the values of the index, and
derive the values of the index each corresponding to one of the plurality of possibilities based on the distribution.
3. An encoding parameter deriving method executed by a computer, the encoding parameter deriving method comprising:
calculating a value of an index indicating a quality of experience of a viewer for each of a plurality of encoded videos generated by encoding an original video by a plurality of combinations of values of encoding parameters, and deriving a relationship between the values of the encoding parameters and the values of the index; and
deriving a plurality of possibilities for a combination of values of the encoding parameters to be used for encoding the original video, based on the relationship,
the encoding parameter deriving method further comprising:
converting time-series data of throughput in a past delivery related to the original video into time-series data of values of the index;
deriving values of the index each corresponding to one of the plurality of possibilities based on the time-series data of the values of the index;
deriving the plurality of possibilities based on the derived values of the index—and the relationship, and
converting time-series data of throughput in the past delivery related to the original video into the time-series data of values of the index by substituting bit rate value at each time point of the time-series data of the bit rate that is obtained for each past delivery, for by of expression (1) to calculate a QoE corresponding to the bit rate value, and arranging the obtained QoE at each time point in time series
Q=c 1 /1+ e −c 2 ×log 10 b v +c 3 (1)
wherein c1, c2, and c3 are constants, and by is the bit rate.
4. The encoding parameter deriving method according to claim 3 , executed by the computer, the encoding parameter deriving method comprising:
deriving a distribution of the values of the index based on the time-series data of the values of the index; and
deriving the values of the index each corresponding to one of the plurality of possibilities based on the distribution.
5. A non-transitory computer-readable recording medium storing a program for causing a computer to execute the encoding parameter deriving method according to claim 3 .