| 摘要 |
A transcoder that controls the amount of generated codes of an output stream toward a target bit rate without degradation of image quality. The transcoder decodes a first stream and encodes the decoded image again to thereby output a second stream. The transcoder calculates a distortion evaluation value from the image obtained by decoding the first stream and an image obtained by decoding the second stream. Assuming that a ratio between the distortion evaluation value and a total target distortion evaluation value is determined as a target distortion ratio, a target setting bit rate of a second stream in the period can be obtained by multiplying a total target bit rate of the second stream by the target distortion ratio. Alternatively, the target setting bit rate can be obtained by adjusting the target distortion ratio with an appropriate function and adding the target distortion ratio to the total target bit rate of the second stream. |
