Video compression and encoding method

1. A method for encoding at least one video frame having a plurality of blocks including a current block, comprising:

identifying one or more prior-coded blocks that, collectively, at least partially surround the current block, wherein at least some of the prior-coded blocks are each associated with a motion vector value;

assigning each of the identified prior-coded blocks to one of a plurality of groups based on that identified prior-coded block's associated motion vector value;

determining, for at least some of the plurality of groups, the number of identified prior-coded blocks assigned to each group;

selecting a mode for the current block;

entropy encoding the selected mode using a probability based on the determined number of identified prior-coded blocks assigned to each group; wherein the steps of determining the number of identified prior-coded blocks assigned to each group includes;

identifying a distance from the current block for each of the identified prior-coded blocks;

applying a weight factor to each of at least some of the identified prior-coded blocks based on that block's distance from the current block; and

increasing the number of identified prior-coded blocks assigned to each group based on the applied weight factors.

2. The method of claim 1 , wherein selecting the mode comprises:

selecting a mode for the current block from a set of modes, wherein the set of modes includes:

a first mode indicative of encoding the current block using no motion vector;

a second mode indicative of encoding the current block using a new motion vector;

a third mode indicative of encoding the current block using a nearest motion vector; and

a fourth mode indicative of encoding the current block using a next nearest motion vector.

3. The method of claim 2 , wherein, if the selected mode is the second mode indicative of encoding the current block using the new motion vector, further comprising:

determining which group of the plurality of groups is assigned a greatest number of blocks; and

using the motion vector value associated with the group assigned the greatest number of blocks to entropy encode the new motion vector for the current block.

4. The method of claim 2 , wherein the plurality of groups comprises:

a first group indicative of a number of identified prior-coded blocks that are encoded using no motion vector;

a second group indicative of a number of identified prior-coded blocks encoded that are encoded using the nearest motion vector;

a third group indicative of a number of identified prior-coded blocks encoded that are encoded using the next nearest motion vector; and

a fourth group indicative of a number of identified prior-coded blocks that are encoded using a motion vector other than no motion vector, the nearest motion vector or the next nearest motion vector.

5. The method of claim 4 , wherein assigning each of the identified prior-coded blocks to one of the plurality of groups, comprises:

assigning the identified prior-coded blocks associated with no motion vector to the first group;

assigning the identified prior-coded blocks associated with the nearest motion vector to the second group;

assigning the identified prior-coded blocks associated with the next nearest motion vector to the third group; and

assigning the identified prior-coded blocks that have not been assigned to the first group, the second group or the third group to the fourth group.

6. The method of claim 5 , wherein determining, for at least some of the plurality of groups, the number of identified prior-coded blocks assigned to each group, comprises:

determining the number of identified prior-coded blocks assigned the first, second, third and fourth groups.

7. The method of claim 1 , wherein the identified prior-coded blocks are twelve blocks neighboring the current block.

8. The method of claim 7 , wherein the twelve blocks include at least a block above the current block and a block to the left of the current block.

9. An apparatus for encoding at least one video frame having a plurality of blocks including a current block, comprising:

a memory; and

a processor configured to execute instructions stored in the memory to:

identify one or more prior-coded blocks that, collectively, at least partially surround the current block, wherein at least some of the prior-coded blocks are each associated with a motion vector value;

assign each of the identified prior-coded blocks to one of a plurality of groups based on that identified prior-coded block's associated motion vector value;

determine, for at least some of the plurality of groups, the number of identified prior-coded blocks assigned to each group;

select a mode for the current block;

entropy encode the selected mode using a probability based on the determined number of identified prior-coded blocks assigned to each group; wherein

the instructions to determine the number of identified prior-coded blocks assigned to each group includes instructions to;

identify a distance from the current block for each of the identified prior-coded blocks;

apply a weight factor to each of at least some of the identified prior-coded blocks based on that block's distance from the current block; and

increase the number of identified prior-coded blocks assigned to each group based on the applied weight factors.

10. The apparatus of claim 9 , wherein the instructions to select the mode for the current block comprises instructions to:

select the mode from a set of modes, wherein the set of modes includes:

a first mode indicative of encoding the current block using no motion vector;

a second mode indicative of encoding the current block using a new motion vector;

a third mode indicative of encoding the current block using a nearest motion vector; and

a fourth mode indicative of encoding the current block using a next nearest motion vector.

11. The apparatus of claim 10 , wherein, if the selected mode is the second mode indicative of encoding the current block using the new motion vector, the processor is further configured to execute instructions stored in the memory to:

determine which group of the plurality of groups is assigned a greatest number of blocks; and

use the motion vector value associated with the group assigned the greatest number of blocks to entropy encode the new motion vector for the current block.

12. The apparatus of claim 10 , wherein the plurality of groups comprises:

a first group indicative of a number of identified prior-coded blocks that are encoded using no motion vector;

a second group indicative of a number of identified prior-coded blocks encoded that are encoded using the nearest motion vector;

a third group indicative of a number of identified prior-coded blocks encoded that are encoded using the next nearest motion vector; and

a fourth group indicative of a number of identified prior-coded blocks that are encoded using a motion vector other than no motion vector, the nearest motion vector or the next nearest motion vector.

13. The apparatus of claim 12 , wherein the instructions to assign each of the identified prior-coded blocks to one of the plurality of groups comprises instructions to:

assign the identified prior-coded blocks associated with no motion vector to the first group;

assign the identified prior-coded blocks associated with the nearest motion vector to the second group;

assign the identified prior-coded blocks associated with the next nearest motion vector to the third group; and

assign the identified prior-coded blocks that have not been assigned to the first group, the second group or the third group to the fourth group.

14. The apparatus of claim 9 , wherein the identified prior-coded blocks are twelve blocks neighboring the current block.

15. The apparatus of claim 14 , wherein the twelve blocks includes at least a block above the current block and a block to the left of the current block.