# q922.h

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    00001 /*
    00002  * q922.h
    00003  *
    00004  * Q.922 PDU implementation for the OpenH323 Project.
    00005  *
    00006  * Copyright (c) 2006 Network for Educational Technology, ETH Zurich.
    00007  * Written by Hannes Friederich.
    00008  *
    00009  * The contents of this file are subject to the Mozilla Public License
    00010  * Version 1.0 (the "License"); you may not use this file except in
    00011  * compliance with the License. You may obtain a copy of the License at
    00012  * http://www.mozilla.org/MPL/
    00013  *
    00014  * Software distributed under the License is distributed on an "AS IS"
    00015  * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
    00016  * the License for the specific language governing rights and limitations
    00017  * under the License.
    00018  *
    00019  * Contributor(s): ______________________________________.
    00020  *
    00021  * $Revision: 21346 $
    00022  * $Author: hfriederich $
    00023  * $Date: 2008-10-15 17:21:15 -0500 (Wed, 15 Oct 2008) $
    00024  */
    00025
    00026 #ifndef OPAL_H224_Q922_H
    00027 #define OPAL_H224_Q922_H
    00028
    00029 #ifdef P_USE_PRAGMA
    00030 #pragma interface
    00031 #endif
    00032
    00033 #ifndef _PTLIB_H
    00034 #include <ptlib.h>
    00035 #endif
    00036
    00037 #include <opal/buildopts.h>
    00038
    00039 #define Q922_HEADER_SIZE 3
    00040
    00041 class Q922_Frame : public PBYTEArray
    00042 {
    00043   PCLASSINFO(Q922_Frame, PBYTEArray);
    00044
    00045 public:
    00046
    00047   Q922_Frame(PINDEX informationFieldSize = 260);
    00048   ~Q922_Frame();
    00049
    00050   BYTE GetHighOrderAddressOctet() const { return theArray[0]; }
    00051   BYTE GetLowOrderAddressOctet() const { return theArray[1]; }
    00052   void SetHighOrderAddressOctet(BYTE octet) { theArray[0] = octet; }
    00053   void SetLowOrderAddressOctet(BYTE octet) { theArray[1] = octet; }
    00054
    00055   BYTE GetControlFieldOctet() const { return theArray[2]; }
    00056   void SetControlFieldOctet(BYTE octet) { theArray[2] = octet; }
    00057
    00058   BYTE *GetInformationFieldPtr() const { return (BYTE *)(theArray + Q922_HEADER_SIZE); }
    00059
    00060   PINDEX GetInformationFieldSize() const { return informationFieldSize; }
    00061   void SetInformationFieldSize(PINDEX size);
    00062
    00066   PBoolean DecodeAnnexQ(const BYTE *buffer, PINDEX size);
    00067
    00070   PINDEX GetAnnexQEncodedSize() const;
    00071
    00075   PBoolean EncodeAnnexQ(BYTE *buffer, PINDEX & size) const;
    00076
    00080   PBoolean DecodeHDLC(const BYTE *data, PINDEX size);
    00081
    00085   PINDEX GetHDLCEncodedSize() const;
    00086
    00090   PBoolean EncodeHDLC(BYTE *buffer, PINDEX & size) const;
    00091
    00099   PBoolean EncodeHDLC(BYTE *buffer, PINDEX & size, BYTE & bitPosition) const;
    00100
    00101 protected:
    00102
    00103   PINDEX informationFieldSize;
    00104
    00105 private:
    00106
    00107   // for HDLC mode
    00108   inline PBoolean FindFlagEnd(const BYTE *buffer, PINDEX bufferSize, PINDEX & octetIndex, BYTE & bitIndex);
    00109   inline BYTE DecodeOctet(const BYTE *buffer, BYTE *destination, PINDEX & octetIndex, BYTE & bitIndex, BYTE & onesCounter);
    00110   inline BYTE DecodeBit(const BYTE *buffer, PINDEX & octetIndex, BYTE & bitIndex);
    00111
    00112   inline void EncodeOctet(BYTE octet, BYTE *buffer, PINDEX & octetIndex, BYTE & bitIndex, BYTE & onesCounter) const;
    00113   inline void EncodeOctetNoEscape(BYTE octet, BYTE *buffer, PINDEX & octetIndex, BYTE & bitIndex) const;
    00114   inline void EncodeBit(BYTE bit, BYTE *buffer, PINDEX & octetIndex, BYTE & bitIndex) const;
    00115
    00116   inline WORD CalculateFCS(const BYTE*data, PINDEX length) const;
    00117 };
    00118
    00119 #endif // OPAL_H224_Q922_H
    00120