Sparse coding dictionary priming

1. A method for use in video coding, the method comprising:

iteratively training a coding dictionary using a processor, wherein the coding dictionary includes a plurality of codewords, by:

identifying a sampling index cardinality;

identifying a portion of a video stream;

decomposing the portion by:

randomly identifying a set of codewords from the plurality of codewords wherein a cardinality of the set of codewords is the sampling index cardinality and wherein the sampling index cardinality is less than a cardinality of the plurality of codewords, and

determining a codeword from the set of codewords, the codeword having a maximum correlation with the portion; and

updating the codeword based on the portion,

wherein the iteratively training the coding dictionary includes increasing the sampling index cardinality in response to an event indicating an expiration of a time period.

2. The method of claim 1 , wherein the iteratively training the coding dictionary includes maintaining an iteration counter and the event indicates that the iteration counter crossed a threshold.

3. The method of claim 1 , wherein the iteratively training the coding dictionary includes decomposing a plurality of portions of a plurality of video streams including the portion of the video stream.

4. The method of claim 1 , further comprising:

generating an encoded video stream by encoding the portion using the codeword; and

transmitting the video stream portion.

5. The method of claim 1 , wherein the iteratively training the coding dictionary includes storing the coding dictionary in a non-transitory machine readable medium.

6. The method of claim 1 , wherein the iteratively training the coding dictionary includes increasing the sampling index cardinality to equal the cardinality of the coding dictionary.

7. The method of claim 1 , further comprising transmitting the coding dictionary to an encoder.

8. The method of claim 1 , further comprising transmitting the coding dictionary to a decoder.

9. An apparatus for decoding a frame in a video stream, the frame having a plurality of blocks, the apparatus comprising:

a memory; and

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

iteratively train a coding dictionary, wherein the coding dictionary includes a plurality of codewords, by:

identify a sampling index cardinality;

identify a portion of a video stream;

decompose the portion by:

randomly identifying a set of codewords from the plurality of codewords wherein a cardinality of the set of codewords is the sampling index cardinality and wherein the sampling index cardinality is less a cardinality of the plurality of codewords, and

determining a codeword from the set of codewords, the codeword having a maximum correlation with the portion; and

update the codeword based on the portion,

wherein iteratively training the coding dictionary includes maintaining a timer and increasing the sampling index cardinality in response to an event indicating an expiration of the timer.

10. The apparatus of claim 9 , wherein the processor is configured to iteratively train the coding dictionary by maintaining an iteration counter and the event indicates that the iteration counter crossed a threshold.

11. The apparatus of claim 9 , wherein the processor is configured to iteratively train the coding dictionary by decomposing a plurality of portions of a plurality of video streams including the portion of the video stream.

12. The apparatus of claim 9 , wherein the processor is configured to:

generate an encoded video stream by encoding the portion using the codeword; and

transmit the video stream portion.

13. The apparatus of claim 9 , wherein the processor is configured to store the coding dictionary in a non-transitory machine readable medium.

14. The apparatus of claim 9 , wherein the processor is configured to iteratively train the coding dictionary by increasing the sampling index cardinality to equal the cardinality of the coding dictionary.

15. The apparatus of claim 9 , wherein the processor is configured to transmit the coding dictionary to an encoder.

16. The apparatus of claim 9 , wherein the processor is configured to transmit the coding dictionary to a decoder.

17. The method of claim 1 , wherein determining a codeword from the set of codewords comprises:

for each codeword of the set of codewords, determining a correlation between the portion of the video stream and the codeword; and

selecting the codeword of the set of codewords having the maximum correlation with the portion of the video stream.

18. The method of claim 1 , wherein updating the codeword based on the portion comprises:

updating the codeword based on a difference between the portion and a weighted combination of the set of codewords.

19. The apparatus of claim 9 , wherein the processor is configured to determine a codeword from the set of codewords by:

for each codeword of the set of codewords, determining a correlation between the portion of the video stream and the codeword; and

selecting the codeword of the set of codewords having the maximum correlation with the portion of the video stream.

20. The apparatus of claim 9 , wherein the processor is configured to update the codeword based on the portion by:

updating the codeword based on a difference between the portion and a weighted combination of the set of codewords.