Click on the button (with the points) right of the window.
Select the SSA files
Click OK
Video>> Compression
Choose the desired codec (normally the same as the movie).
It is better to encode in 2 passes. Indeed, in 1 pass, the encoding will be done in CBR (Constant Bit Rate), the fast and slow sequences are encoded with the same amount of information per second. The 2-pass will be made in VBR (Variable Bit Rate), ie the rapid sequence will be encoded with a high bit rate whereas the slow sequences with bit rates will be lower.
Click the button "Configure". In the new window, choose "2 pass - first pass".
Click OK and then OK
File>> Save as AVI, give a different name and let the process unfold.
When the first pass and finished, you get a file containing some informations about the bitrate.
Video> Compression>> Sets
Choose 2 pass - second pass and start a new backup under another name.
