Set the absolute output volume including the RVA setting, vol<0 just applies (a possibly changed) RVA setting. \param mh handle \param vol volume value (linear factor) \return MPG123_OK on success
See Implementation
Set the absolute output volume including the RVA setting, vol<0 just applies (a possibly changed) RVA setting. \param mh handle \param vol volume value (linear factor) \return MPG123_OK on success