The subfile protocol treats an end of 0 as meaning "until EOF"; this got
implemented by simply setting the end to INT64_MAX. But seeking relative
to EOF or AVSEEK_SIZE seeking hasn't been adapted; the result is that
e.g. the duration of transport streams isn't correctly determined when
this option is used. This is fixed in this patch.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>