Method encodeSymbol

src/arithmeticencoder.cpp:222–244

}

void ArithmeticEncoder::encodeSymbol(ArithmeticModel* m, U32 sym)
{
  assert(m && (sym <= m->last_symbol));

  U32 x, init_base = base;
                                                           // compute products
  if (sym == m->last_symbol) {
    x = m->distribution[sym] * (length >> DM__LengthShift);
    base   += x;                                            // update interval
    length -= x;                                          // no product needed
  }
  else {
    x = m->distribution[sym] * (length >>= DM__LengthShift);
    base   += x;                                            // update interval
    length  = m->distribution[sym+1] * length - x;
  }

  if (init_base > base) propagate_carry();                 // overflow = carry
  if (length < AC__MinLength) renorm_enc_interval();        // renormalization

  ++m->symbol_count[sym];
  if (--m->symbols_until_update == 0) m->update();    // periodic model update
}

void ArithmeticEncoder::writeBit(U32 sym)
{