Patent ID: 8467448
Filing Date: 2013-06-18
Classification: H04N

Abstract:
1. A method for fast video encoding on a mobile device, comprising: estimating a rate-distortion cost for a plurality of predictors for coding a video; selecting a predictive coding mode for the video based on a minimization of the rate-distortion cost; coding the image using the predictive mode associated with the minimum rate-distortion cost; evaluating statistical information across the plurality of predictors collected from previous rate-distortion estimations; and providing an early termination for computing rate-distortion costs that exceed a threshold based on the statistical information; wherein the estimating a rate-distortion cost is performed across a plurality of intra macro-block modes and a plurality of inter macro-block modes for reducing computational complexity associated with rate-distortion costs of intra macro-block modes; wherein estimating a rate-distortion comprises: computing an inter rate-distortion cost for coding using the inter macro-block modes; setting the minimum rate-distortion cost to the inter rate-distortion cost; and comparing the inter rate-distortion cost to a first threshold; wherein comparing the inter rate-distortion cost comprises: if the inter rate-distortion cost is greater than the first threshold, then computing a first intra rate-distortion cost using a first intra macro-block mode for generating a coarse approximation of the rate-distortion cost; and if the inter rate-distortion cost is less than the first threshold, then not selecting the first Intra macro-block mode; the method further comprising: computing a second intra rate-distortion cost using a second Intra macro-block mode; comparing the second intra rate-distortion cost to the minimum rate-distortion cost and updating a minimum rate-distortion cost based on the comparing; wherein updating includes: setting the minimum rate-distortion cost to the second intra rate-distortion cost if the second intra rate-distortion cost is less than a current minimum rate-distortion cost; the method further comprising: comparing an approximated first intra rate-distortion cost to a second threshold; and if the approximated first intra rate-distortion cost is less than the second threshold, then refining the approximated first intra rate-distortion cost; and if the approximated first intra rate-distortion cost is greater than the second threshold, then not updating the approximated first intra rate-distortion cost in view that the first intra mode is unlikely to be an optimal macro-block.