session-ios/Libraries/spandsp/spandsp/spandsp/crc.h

99 lines
3.3 KiB
C

/*
* SpanDSP - a series of DSP components for telephony
*
* crc.h
*
* Written by Steve Underwood <steveu@coppice.org>
*
* Copyright (C) 2003 Steve Underwood
*
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License version 2.1,
* as published by the Free Software Foundation.
*
* This program 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* $Id: crc.h,v 1.5 2009/01/31 08:48:11 steveu Exp $
*/
/*! \file */
/*! \page crc_page CRC
\section crc_page_sec_1 What does it do?
\section crc_page_sec_2 How does it work?
*/
#if !defined(_SPANDSP_CRC_H_)
#define _SPANDSP_CRC_H_
#if defined(__cplusplus)
extern "C"
{
#endif
/*! \brief Calculate the ITU/CCITT CRC-32 value in buffer.
\param buf The buffer containing the data.
\param len The length of the frame.
\param crc The initial CRC value. This is usually 0xFFFFFFFF, or 0 for a new block (it depends on
the application). It is previous returned CRC value for the continuation of a block.
\return The CRC value.
*/
SPAN_DECLARE(uint32_t) crc_itu32_calc(const uint8_t *buf, int len, uint32_t crc);
/*! \brief Append an ITU/CCITT CRC-32 value to a frame.
\param buf The buffer containing the frame. This must be at least 2 bytes longer than
the frame it contains, to allow room for the CRC value.
\param len The length of the frame.
\return The new length of the frame.
*/
SPAN_DECLARE(int) crc_itu32_append(uint8_t *buf, int len);
/*! \brief Check the ITU/CCITT CRC-32 value in a frame.
\param buf The buffer containing the frame.
\param len The length of the frame.
\return TRUE if the CRC is OK, else FALSE.
*/
SPAN_DECLARE(int) crc_itu32_check(const uint8_t *buf, int len);
/*! \brief Calculate the ITU/CCITT CRC-16 value in buffer.
\param buf The buffer containing the data.
\param len The length of the frame.
\param crc The initial CRC value. This is usually 0xFFFF, or 0 for a new block (it depends on
the application). It is previous returned CRC value for the continuation of a block.
\return The CRC value.
*/
SPAN_DECLARE(uint16_t) crc_itu16_calc(const uint8_t *buf, int len, uint16_t crc);
/*! \brief Append an ITU/CCITT CRC-16 value to a frame.
\param buf The buffer containing the frame. This must be at least 2 bytes longer than
the frame it contains, to allow room for the CRC value.
\param len The length of the frame.
\return The new length of the frame.
*/
SPAN_DECLARE(int) crc_itu16_append(uint8_t *buf, int len);
/*! \brief Check the ITU/CCITT CRC-16 value in a frame.
\param buf The buffer containing the frame.
\param len The length of the frame.
\return TRUE if the CRC is OK, else FALSE.
*/
SPAN_DECLARE(int) crc_itu16_check(const uint8_t *buf, int len);
#if defined(__cplusplus)
}
#endif
#endif
/*- End of file ------------------------------------------------------------*/