[Guy Harris <gharris@xxxxxxxxxxxx>]

Tethereal now lets you use a read filter when doing a live capture; if a
read filter is specified, only packets that pass the read filter as well
as any capture filter that was specified will be printed or written to
the output file.  Read filters take more work to evaluate, however, so
specifying a read filter might make it harder for Tethereal to keep up
with a very active network.

It also lets you specify an output file when reading a saved capture
file, so that you can use Tethereal to convert a file from one capture
file format to another by using "-r", "-w", and "-F", and can also use
it to extract selected packets from a capture file and write them to
another file by using "-r", "-w", and "-R".  ("-F" and "-R" can, of
course, be used together....)

The packet count displayed during a live capture doesn't take into
account the read filter, only the capture filter; this isn't
intentional, but it looks as if it might be a slight pain to fix - I'll
look into it.