Patent ID: 7349472

Claim:
A method for transcoding a video, comprising: modeling a requantization of an input video as a first rate-distortion function of an input video; modeling a resynchronization marker insertion rate as a second rate-distortion function of the input video; modeling an intra-block insertion as a third rate-distortion function of the input video; and transcoding the input video according to the first, second and third rate-distortion functions to produce an output video, in which the input video has a first bit rate greater than a second bit rate of the output video, and a distortion D is expressed as D = [ ∏ i = 0 L - 1 ⁢ Φ ⁡ ( ω i ) ] 1 / L · ⅇ - β · R ⁡ ( D ) , where L is a total number of frequency coefficients of a discrete cosine transform in the input video, Φ(ω i ) is a power spectrum density function of coefficient i, R is the second bit rate, and β is 21n2.