Open the 'civ' interface and enter again the .avi file as input. Introduce the image calibration 'pxcmx' and 'pxcmy' in the edit boxes on the upper right. With our choice of processing pair '-8|8' in 'CIV1_PAIR', let us for instance get a velocity field every 4 seconds (100 frames) during the whole period of record, so we set 'image #' 1 ('first') 100 ('increment') 2001 ('last'). Create a new subdirectory, for instance B, in 'SUBDIR_CIV1', to avoid confusion with the previous tests. Then press 'RUN'. The first and last frames are automatically adjusted according to the existing images: since the image 1-8=-7 needed for the first pair does not exist, the next field on the list, #101 is taken as the first one. The last field is similarly adjusted.
The image obtained from the frame number i of the avi file 'movie.avi' is named 'movie_i.png'. The velocity field resulting from the image pair i1, i2 is stored as a netcdf file 'movie_i1-i2.nc' in the subdirectory defined in the 'civ' interface. In this subdirectory, the text file 'movie_i1-i2.cmx' contains the parameters sent to the civ programme, while the text files 'movie_i1-i2.log' or 'movie_i1-i2_patch.log' contains some information about the computations from the fortran programmes. These can be opened by the uvmat interface browser (or by any text editor), which can be useful for trouble shooting.