gst_element_query_duration() fails for certain filetypes

[Nate Bogdanowicz]

> Try using GST_FORMAT_TIME, if that works better.
>
> DEFAULT is supposed to mean samples for audio and frames for video, but
> may or may not work depending on media and elements involved.
>

That worked! It seems that some decoder elements must not support
DEFAULT/BYTES, which are the two I've been trying to use. TIME worked
for all the files I just tried, so I'll just do my own conversion to
number of samples.

Thanks for the help,
Nate