Patent ID: 7881384

Claim:
A method for transcoding from an H.264 format to an MPEG-2 format, comprising the steps of: (A) decoding an input video stream in said H.264 format to generate a picture having a plurality of macroblock pairs that use an H.264 macroblock adaptive field/frame coding; (B) determining a mode indicator for each of said macroblock pairs; (C) coding said macroblock pairs into an output video stream in said MPEG-2 format using one of (i) an MPEG-2 field mode coding and (ii) an MPEG-2 frame mode coding as determined from said mode indicators; and (D) comparing a residual vertical field activity with a residual frame activity to generate a residual indicator, wherein use of (i) said MPEG-2 field mode coding and (ii) said MPEG-2 frame mode coding is further determined by said residual indicator.