Merge pull request #28 from j-b-m/master

Fix maxangle in vstab transcode
Fix handling filenames in XML with leading or trailing spaces (SF-193).
Fix regression in most recent commit d658f9b.

It could trigger audio encode errors.
Extend samples-per-frame fix to multi audio stream out.
Fail on continual encoding errors.

Prevents an infinite loop that may occur.
Make framebuffer producer recover from broken frame instead of producing white frames forever