I found cryptkeeper's lib on github to decode .fseq file and drive pixel led as per whatever patterns rendered in Xlights.
For that i need sd card ( for store .fseq file)
Instead of sd card i think 64 mb or 128mb flash ic will works.
For that i need complete raw data according frames & RGB order(whatever i defined)
2nd option is :- is it possible to export exactly same size avi video ? Defined in layout
Like if i create 50x20 matrix , exported videos size will be same as 50x20