+/*
+ Copyright (C) 2020 Carl Hetherington <cth@carlh.net>
+
+ This file is part of libdcp.
+
+ libdcp is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ libdcp is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with libdcp. If not, see <http://www.gnu.org/licenses/>.
+
+ In addition, as a special exception, the copyright holders give
+ permission to link the code of portions of this program with the
+ OpenSSL library under certain conditions as described in each
+ individual source file, and distribute linked combinations
+ including the two.
+
+ You must obey the GNU General Public License in all respects
+ for all of the code used other than OpenSSL. If you modify
+ file(s) with this exception, you may extend this exception to your
+ version of the file(s), but you are not obligated to do so. If you
+ do not wish to do so, delete this exception statement from your
+ version. If you delete this exception statement from all source
+ files in the program, then also delete it here.
+*/
+
+
+#include "bitstream.h"
+#include "dcp_assert.h"
+#include <iostream>
+#include <stdint.h>
+#include <string.h>
+
+
+using namespace dcp;
+
+
+void
+Bitstream::write_bit (bool bit)
+{
+ if (_crc) {
+ _crc->process_bit (bit);
+ }
+ _data.push_back (bit);
+}
+
+
+void
+Bitstream::write_from_byte (uint8_t byte, int bits)
+{
+ for (int i = bits - 1; i >= 0; --i) {
+ write_bit ((byte >> i) & 1);
+ }
+}
+
+
+void
+Bitstream::write_from_word (uint32_t word, int bits)
+{
+ for (int i = bits - 1; i >= 0; --i) {
+ write_bit ((word >> i) & 1);
+ }
+}
+
+
+void
+Bitstream::start_crc (uint16_t poly)
+{
+ DCP_ASSERT (!static_cast<bool>(_crc));
+ _crc = boost::crc_basic<16> (poly);
+}
+
+
+void
+Bitstream::write_crc ()
+{
+ DCP_ASSERT (static_cast<bool>(_crc));
+ uint16_t crc = _crc->checksum();
+ write_from_word (crc, 16);
+ _crc = boost::none;
+}
+