Methods for efficient implementation of skip/direct modes in digital video compression algorithms
View Patent ↗A method for selecting a picture prediction mode from a candidate pool of picture prediction modes for video compression takes advantage of similarity in implementation between SKIP and DIRECT modes and one other inter-picture prediction modes, namely, the 16×16 partition mode. The SKIP/DIRECT modes are considered if and only if the final prediction information of the 16×16 partition mode, including motion vector, reference picture index, and prediction direction, is the same as that of the respective SKIP and/or DIRECT modes. The same motion prediction, reference picture index and prediction direction are used for the 16×16 partition mode and the SKIP/DIRECT modes, and therefore, the same interpolation scheme can be used for both SKIP/DIRECT and 16×16 partition modes.
1. A method for prediction mode selection for video compression among a plurality of prediction modes, comprising:
calculating prediction information for each of the prediction modes, including
calculating, by using a 16×16 partition mode, a first motion vector, a first reference picture index, and a first prediction direction; and
calculating, by using a direct mode, a second motion vector, a second reference picture index, and a second prediction direction;
comparing calculated prediction information of the 16×16 partition mode to the calculated prediction mode of the direct mode;
retaining certain ones of the prediction modes as a function of said compared prediction information; where the retaining further comprises
removing the direct mode if said first motion vector is not equal to said second motion vector; and
retaining the direct mode if said first motion vector equals said second motion vector, said first reference picture index equals said second reference picture index, and
said first prediction direction equals said second prediction direction; and
selecting a prediction mode from the retained prediction modes.
2. The method of claim 1 , wherein the retaining further comprises removing the direct mode if said first motion vector is not equal to said second motion vector.
3. The method of claim 1 , wherein the retaining further comprises:
removing the direct mode if said first motion vector is not equal to said second motion vector,
otherwise, removing the direct mode if a coded block pattern is equal to zero.
4. The method of claim 1 , wherein the retaining further comprises removing the direct mode if said first reference picture index is not equal to said second reference picture index.
5. The method of claim 1 , wherein the retaining further comprises removing the direct mode if said first prediction direction is not equal to said second prediction direction.
6. The method of claim 1 , wherein the retaining further comprises:
removing the direct mode if said first reference picture index is not equal to said second reference picture index,
otherwise, removing the direct mode if a coded block pattern is equal to zero.
7. The method of claim 1 , wherein the retaining further comprises:
removing the direct mode if said first prediction direction is not equal to said second prediction direction,
otherwise, removing the direct mode if a coded block pattern is equal to zero.