Methods and systems for prediction filtering in video coding

A decoder for decoding a bitstream of encoded video to reconstruct coefficients of a coefficient group in a video decoder, the coefficient group including an upper left coefficient, the decoder comprising:

• a processor;
• a memory;
• and
• a decoding application stored in memory and containing instructions for configuring the processor to decode video from a bitstream of encoded video, the video including a picture partitioned into blocks, wherein the instructions, when executed, configure the processor to:
• decode a filtered-prediction flag and prediction information for one of the blocks,
• construct a prediction block of predicted samples for said one of the blocks based on the prediction information and previously-reconstructed pixel data of the video,
• filter the predicted samples of the constructed prediction block using a filter if the decoded filtered-prediction flag is set,
• decode residual data for said one of the blocks, and
• reconstruct said one of the blocks by adding the decoded residual data to the filtered predicted samples.

A method of encoding video using a video encoder, the video including a picture partitioned into blocks, the method comprising:

• generating a prediction block of predicted samples for one of the blocks based on previously-reconstructed pixel data of the video;
• determining that the prediction block is to be filtered, and filtering the predicted samples of the prediction block to create a filtered prediction block;
• calculating a residual from the difference between the filtered prediction block and said one of the blocks;
• and
• encoding said residual together with a filtered-prediction flag indicating that the prediction block was filtered.