What command lines to use to convert from avi to mp4, but without destroying the framesize and making the file small as the original size or a little bit bigger, and same thing with mp4 to avi? Whenever I tried converting it became like 2 gb
Depending on how your original file was encoded, it may not be possible to keep the file size.
should keep frame sizes and rates intact while making an mp4 file.
will give you information about your input file - the frame size, codecs used, bitrate, etc.
You can also play with the