how to convert mkv,flv files to avi format without decoding?

[Ganesh Ujwal]

how to convert mkv,flv files to avi format without decoding and also output file size should not be increased and it must equal to size of input file size?

[Simond]

What you are asking is not possible, because when you will convert the files in .avi, whose file format is considered as dvd formats, the file size of the video will obviously increase and without a video converter it is impossible to convert those files. Decoding on the other hand is not required, but when a file is converted, it will require some kind of encoding.