if (i == len && tmp != stop) return len+1;
static int get_prefix(GetBitContext *gb, int stop, int len){#if 1  int i = 0, tmp = !stop;  while (i != len && tmp != stop)  {    tmp = get_bits(gb, 1);    i++;  }  return i;#else  unsigned int buf;  int log;  OPEN_READER(re, gb);  UPDATE_CACHE(re, gb);  buf=GET_CACHE(re, gb); //Still not sure  if (stop) buf = ~buf;    log= av_log2(-buf); //FIXME: -?  if (log < limit){    LAST_SKIP_BITS(re, gb, log+1);    CLOSE_READER(re, gb);    return log;  }    LAST_SKIP_BITS(re, gb, limit);  CLOSE_READER(re, gb);  return limit;#endif}