Not very often, but maybe 1 in 50 times, I get a crash with the above-mentioned log.

  assert(enc->buffer_end <= BUFFER_SAMPLES);
  encode_buffer(enc);
  if (enc->unrecoverable) return enc->unrecoverable;
  /* Draining should have called all the streams to complete. */
  assert(enc->streams == NULL); /* <-- the line where the crash happens */
  return OPE_OK;
}

Of course I'd much rather have this NOT crashing. What can I do in order to prevent this from happening? Can there be a "bad moment" to call the drain() such as immediately after starting to encode (which is how I was able to reproduce the bug if it wasn't a coincidence). Should I check for anything else before draining so I don't run into the assert?

Sorry for the dumb question but is C thread safe in this regard or could calling drain() and a simultaneous ope_encoder_write[/_float] cause this?