Patent ID: 8085853

Claim:
A video decoding and transcoding method, which decodes, displays and transcodes a video stream with a sequence of frames and temporarily stores decoded frames in a plurality of frame buffers, each of the decoded frames having a first field and a second field, the method comprising the steps: a decoding procedure, which checks whether a frame buffer is usable when a previous frame is completely decoded and subsequently decodes a current frame, temporarily stores a decoded frame corresponding to the current frame in the frame buffer and sets a frame flag corresponding to the frame buffer when the frame buffer is usable, wherein the decoding procedure does not decode the current frame when the frame buffer is not usable and sets a decoding flag to indicate that the current frame is waiting for decoding; a displaying procedure, which checks whether the frame buffer temporarily stores the decoded current frame when a previous field is completely displayed and subsequently reads and displays the decoded current frame when the frame buffer temporarily stores the decoded current frame, wherein the displaying procedure checks the decoding flag when the previous field is completely displayed and triggers the decoding procedure when the decoding flag is set; and a transcoding procedure, which checks whether the frame buffer temporarily stores the decoded current frame when the previous frame is completely decoded and subsequently reads and transcodes the decoded current frame when the frame buffer temporarily stores the decoded current frame.