Merge remote-tracking branch 'tjoppen/mxf_fixes_20111220'

* tjoppen/mxf_fixes_20111220:
  mxfdec: Sanity-check SampleRate
  mxfdec: Make sure mxf->nb_index_tables > 0 in mxf_packet_timestamps()
  mxfdec: Remove unused variables
  mxfdec: Make sure x < index_table->nb_ptses
  mxfdec: Ignore the last entry in Avid's index table segments

Merged-by: Michael Niedermayer <michaelni@gmx.at>