title: What's the difference between CRA picture and BLA picture?
body: <p>According to HEVC spec:<br></p>
  
  <p>A clean random access (CRA) picture may have associated random access skipped leading (RASL) or random access decodable leading (RADL) pictures present in the bitstream.</p>
  
  <p>A broken link access (BLA) picture having nal_unit_type equal to BLA_W_LP may have associated RASL or RADL pictures present in the bitstream. A BLA picture having nal_unit_type equal to BLA_W_RADL does not have associated RASL pictures present in the bitstream, but may have associated RADL pictures in the bitstream. A BLA picture having nal_unit_type equal to BLA_N_LP does not have associated leading pictures present in the bitstream</p>
  
  <p>Except the containing different NAL_unit type, there seems to be no difference between CRA and BLA with nal_unit_type equal to BLA_W_LP.</p>
  
  <p>Any difference between them?</p>