[FFmpeg-user] Specify log file for 2-pass encoding

[James Board]

I'm using ffmpeg to do 2-pass mpeg encoding with '-ovc lavc' and the
mpeg4 codec on Linux.  This
generates a divx2pass.log file in the directory where the files are located.
I'm trying to encode multiple files at the same time on different CPU cores
and the log files are clobbering each
other.  How can I specify which name
I'd like the log file to have?  The ffmpeg man page says the -passlogfile can
be used to specify
the logfile for pass 1.  But how do I tell ffmpeg to use that
log file in pass 2?

The man page and the HTML documentation doesn't mention divx2pass.log.
Thanks