Sparse coding dictionary priming

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.