www.pudn.com > VOIP(H323).rar > encode.c
/* * Copyright (C) 2004 by Objective Systems, Inc. * * This software is furnished under an open source license and may be * used and copied only in accordance with the terms of this license. * The text of the license may generally be found in the root * directory of this installation in the LICENSE.txt file. It * can also be viewed online at the following URL: * * http://www.obj-sys.com/open/license.html * * Any redistributions of this file including modified versions must * maintain this copyright notice. * *****************************************************************************/ #include#include "ooasn1.h" #include #include "g72x.h" #include "g711.h" static int encode16BitConstrainedString (OOCTXT* pctxt, Asn116BitCharString value, Asn116BitCharSet* pCharSet); static int encode2sCompBinInt (OOCTXT* pctxt, ASN1INT value); static int encodeNonNegBinInt (OOCTXT* pctxt, ASN1UINT value); static int encodeUnconsLength (OOCTXT* pctxt, ASN1UINT value); static int getIdentByteCount (ASN1UINT ident); int encodeBit (OOCTXT* pctxt, ASN1BOOL value) { int stat = ASN_OK; /* If start of new byte, init to zero */ if (pctxt->buffer.bitOffset == 8) { pctxt->buffer.data[pctxt->buffer.byteIndex] = 0; } /* Adjust bit offset and determine if at end of current byte */ if (--pctxt->buffer.bitOffset < 0) { if (++pctxt->buffer.byteIndex >= pctxt->buffer.size) { if ((stat = encodeExpandBuffer (pctxt, 1)) != ASN_OK) { return stat; } } pctxt->buffer.data[pctxt->buffer.byteIndex] = 0; pctxt->buffer.bitOffset = 7; } /* Set single-bit value */ if (value) { pctxt->buffer.data[pctxt->buffer.byteIndex] |= ( 1 << pctxt->buffer.bitOffset ); } /* If last bit in octet, set offsets to start new byte (ED, 9/7/01) */ if (pctxt->buffer.bitOffset == 0) { pctxt->buffer.bitOffset = 8; pctxt->buffer.byteIndex++; pctxt->buffer.data[pctxt->buffer.byteIndex] = 0; } return stat; } int encodeBits (OOCTXT* pctxt, ASN1UINT value, ASN1UINT nbits) { int nbytes = (nbits + 7)/ 8, stat = ASN_OK; if (nbits == 0) return stat; /* If start of new byte, init to zero */ if (pctxt->buffer.bitOffset == 8) { pctxt->buffer.data[pctxt->buffer.byteIndex] = 0; } /* Mask off unused bits from the front of the value */ if (nbits < (sizeof(ASN1UINT) * 8)) value &= ((1 << nbits) - 1); /* If bits will fit in current byte, set them and return */ if (nbits < (unsigned)pctxt->buffer.bitOffset) { pctxt->buffer.bitOffset -= nbits; pctxt->buffer.data[pctxt->buffer.byteIndex] |= ( value << pctxt->buffer.bitOffset ); return stat; } /* Check buffer space and allocate more memory if necessary */ stat = encodeCheckBuffer (pctxt, nbytes); if (stat != ASN_OK) return LOG_ASN1ERR (pctxt, stat); /* Set bits in remainder of the current byte and then loop */ /* to set bits in subsequent bytes.. */ nbits -= pctxt->buffer.bitOffset; pctxt->buffer.data[pctxt->buffer.byteIndex++] |= (ASN1OCTET)( value >> nbits ); pctxt->buffer.data[pctxt->buffer.byteIndex] = 0; while (nbits >= 8) { nbits -= 8; pctxt->buffer.data[pctxt->buffer.byteIndex++] = (ASN1OCTET)( value >> nbits ); pctxt->buffer.data[pctxt->buffer.byteIndex] = 0; } /* copy final partial byte */ pctxt->buffer.bitOffset = 8 - nbits; if (nbits > 0) { pctxt->buffer.data[pctxt->buffer.byteIndex] = (ASN1OCTET)((value & ((1 << nbits)-1)) << pctxt->buffer.bitOffset); } else pctxt->buffer.data[pctxt->buffer.byteIndex] = 0; return stat; } int encodeBitsFromOctet (OOCTXT* pctxt, ASN1OCTET value, ASN1UINT nbits) { int lshift = pctxt->buffer.bitOffset; int rshift = 8 - pctxt->buffer.bitOffset; int stat = ASN_OK; ASN1OCTET mask; if (nbits == 0) return ASN_OK; /* Mask off unused bits from the end of the value */ if (nbits < 8) { switch (nbits) { case 1: mask = 0x80; break; case 2: mask = 0xC0; break; case 3: mask = 0xE0; break; case 4: mask = 0xF0; break; case 5: mask = 0xF8; break; case 6: mask = 0xFC; break; case 7: mask = 0xFE; break; default:; } value &= mask; } /* If we are on a byte boundary, we can do a direct assignment */ if (pctxt->buffer.bitOffset == 8) { pctxt->buffer.data[pctxt->buffer.byteIndex] = value; if (nbits == 8) { pctxt->buffer.byteIndex++; pctxt->buffer.data[pctxt->buffer.byteIndex] = 0; } else pctxt->buffer.bitOffset -= nbits; } /* Otherwise, need to set some bits in the first octet and */ /* possibly some bits in the following octet.. */ else { pctxt->buffer.data[pctxt->buffer.byteIndex] |= (ASN1OCTET)(value >> rshift); pctxt->buffer.bitOffset -= nbits; if (pctxt->buffer.bitOffset < 0) { pctxt->buffer.byteIndex++; pctxt->buffer.data[pctxt->buffer.byteIndex] = (ASN1OCTET)(value << lshift); pctxt->buffer.bitOffset += 8; } } return stat; } int encodeBitString (OOCTXT* pctxt, ASN1UINT numbits, const ASN1OCTET* data) { int enclen, octidx = 0, stat; Asn1SizeCnst* pSizeList = pctxt->pSizeConstraint; for (;;) { if ((enclen = encodeLength (pctxt, numbits)) < 0) { return LOG_ASN1ERR (pctxt, enclen); } if (enclen > 0) { ASN1BOOL doAlign; stat = bitAndOctetStringAlignmentTest (pSizeList, numbits, TRUE, &doAlign); if (stat != ASN_OK) return LOG_ASN1ERR (pctxt, stat); if (doAlign) { stat = encodeByteAlign (pctxt); if (stat != ASN_OK) return LOG_ASN1ERR (pctxt, stat); } stat = encodeOctets (pctxt, &data[octidx], enclen); if (stat != ASN_OK) return LOG_ASN1ERR (pctxt, stat); } if (enclen < (int)numbits) { numbits -= enclen; octidx += (enclen/8); } else break; } return ASN_OK; } int encodeBMPString (OOCTXT* pctxt, ASN1BMPString value, Asn116BitCharSet* permCharSet) { Asn116BitCharSet charSet; int stat; /* Set character set */ init16BitCharSet (&charSet, BMP_FIRST, BMP_LAST, BMP_ABITS, BMP_UBITS); if (permCharSet) { set16BitCharSet (pctxt, &charSet, permCharSet); } /* Encode constrained string */ stat = encode16BitConstrainedString (pctxt, value, &charSet); if (stat != ASN_OK) return LOG_ASN1ERR (pctxt, stat); return stat; } int encodeByteAlign (OOCTXT* pctxt) { if (pctxt->buffer.bitOffset != 8) { if ((pctxt->buffer.byteIndex + 1) >= pctxt->buffer.size) { int stat = encodeExpandBuffer (pctxt, 1); if (stat != ASN_OK) return (stat); } pctxt->buffer.byteIndex++; pctxt->buffer.bitOffset = 8; pctxt->buffer.data[pctxt->buffer.byteIndex] = 0; } return ASN_OK; } int encodeCheckBuffer (OOCTXT* pctxt, ASN1UINT nbytes) { int stat = ASN_OK; /* Add one to required bytes because increment logic will always */ /* init the byte at the incremented index to zero.. */ if ( ( pctxt->buffer.byteIndex + nbytes + 1 ) >= pctxt->buffer.size ) { if ((stat = encodeExpandBuffer (pctxt, nbytes+1)) != ASN_OK) { return LOG_ASN1ERR (pctxt, stat); } } return (stat); } int encodeConsInteger (OOCTXT* pctxt, ASN1INT value, ASN1INT lower, ASN1INT upper) { ASN1UINT range_value; ASN1UINT adjusted_value; int stat; /* Check value against given range */ if (value < lower || value > upper) { return ASN_E_CONSVIO; } /* Adjust range value based on lower/upper signed values and */ /* other possible conflicts.. */ if ((upper > 0 && lower >= 0) || (upper <= 0 && lower < 0)) { range_value = upper - lower; adjusted_value = value - lower; } else { range_value = upper + abs(lower); adjusted_value = value + abs(lower); } if (range_value != ASN1UINT_MAX) { range_value += 1; } if (range_value == 0 || lower > upper) stat = ASN_E_RANGERR; else if (lower != upper) { stat = encodeConsWholeNumber (pctxt, adjusted_value, range_value); } else stat = ASN_OK; return stat; } int encodeConsUnsigned (OOCTXT* pctxt, ASN1UINT value, ASN1UINT lower, ASN1UINT upper) { ASN1UINT range_value; ASN1UINT adjusted_value; int stat; /* Check for special case: if lower is 0 and upper is ASN1UINT_MAX, */ /* set range to ASN1UINT_MAX; otherwise to upper - lower + 1 */ range_value = (lower == 0 && upper == ASN1UINT_MAX) ? ASN1UINT_MAX : upper - lower + 1; adjusted_value = value - lower; if (lower != upper) { stat = encodeConsWholeNumber (pctxt, adjusted_value, range_value); } else stat = ASN_OK; return stat; } int encodeConsWholeNumber (OOCTXT* pctxt, ASN1UINT adjusted_value, ASN1UINT range_value) { ASN1UINT nocts, range_bitcnt = getUIntBitCount (range_value - 1); int stat; if (adjusted_value >= range_value && range_value != ASN1UINT_MAX) { return LOG_ASN1ERR (pctxt, ASN_E_RANGERR); } /* If range is <= 255, bit-field case (10.5.7a) */ if (range_value <= 255) { return encodeBits (pctxt, adjusted_value, range_bitcnt); } /* If range is exactly 256, one-octet case (10.5.7b) */ else if (range_value == 256) { stat = encodeByteAlign (pctxt); if (stat != ASN_OK) return LOG_ASN1ERR (pctxt, stat); return encodeBits (pctxt, adjusted_value, 8); } /* If range > 256 and <= 64k (65536), two-octet case (10.5.7c) */ else if (range_value <= 65536) { stat = encodeByteAlign (pctxt); if (stat != ASN_OK) return LOG_ASN1ERR (pctxt, stat); return encodeBits (pctxt, adjusted_value, 16); } /* If range > 64k, indefinite-length case (10.5.7d) */ else { /* Encode length determinant as a constrained whole number. */ /* Constraint is 1 to max number of bytes needed to hold */ /* the target integer value.. */ if (adjusted_value < 256) nocts = 1; else if (adjusted_value < 65536) nocts = 2; else if (adjusted_value < 0x1000000) nocts = 3; else nocts = 4; stat = encodeBits (pctxt, nocts - 1, 2); if (stat != ASN_OK) return LOG_ASN1ERR (pctxt, stat); stat = encodeByteAlign (pctxt); if (stat != ASN_OK) return LOG_ASN1ERR (pctxt, stat); return encodeNonNegBinInt (pctxt, adjusted_value); } } int encodeConstrainedStringEx (OOCTXT* pctxt, const char* string, const char* charSet, ASN1UINT abits, /* aligned char bits */ ASN1UINT ubits, /* unaligned char bits */ ASN1UINT canSetBits) { ASN1UINT i, len = strlen(string); int stat; /* note: need to save size constraint for use in alignCharStr */ /* because it will be cleared in encodeLength from the context.. */ Asn1SizeCnst* psize = pctxt->pSizeConstraint; /* Encode length */ stat = encodeLength (pctxt, len); if (stat < 0) return LOG_ASN1ERR (pctxt, stat); /* Byte align */ if (alignCharStr (pctxt, len, abits, psize)) { stat = encodeByteAlign (pctxt); if (stat != ASN_OK) return LOG_ASN1ERR (pctxt, stat); } /* Encode data */ if (abits >= canSetBits && canSetBits > 4) { for (i = 0; i < len; i++) { if ((stat = encodeBits (pctxt, string[i], abits)) != ASN_OK) return LOG_ASN1ERR (pctxt, stat); } } else if (0 != charSet) { ASN1UINT nchars = strlen(charSet), pos; const char* ptr; for (i = 0; i < len; i++) { ptr = memchr (charSet, string[i], nchars); if (0 == ptr) return LOG_ASN1ERR (pctxt, ASN_E_CONSVIO); else pos = ptr - charSet; if ((stat = encodeBits (pctxt, pos, abits)) != ASN_OK) return LOG_ASN1ERR (pctxt, stat); } } else return LOG_ASN1ERR (pctxt, ASN_E_INVPARAM); return stat; } int encodeExpandBuffer (OOCTXT* pctxt, ASN1UINT nbytes) { if (pctxt->buffer.dynamic) { /* If dynamic encoding is enabled, expand the current buffer to */ /* allow encoding to continue. */ pctxt->buffer.size += ASN1MAX (ASN_K_ENCBUFSIZ, nbytes); pctxt->buffer.data = (ASN1OCTET*) memHeapRealloc (&pctxt->pMsgMemHeap, pctxt->buffer.data, pctxt->buffer.size); if (!pctxt->buffer.data) return (ASN_E_NOMEM); return (ASN_OK); } return (ASN_E_BUFOVFLW); } int encodeGetMsgBitCnt (OOCTXT* pctxt) { int numBitsInLastByte = 8 - pctxt->buffer.bitOffset; return ((pctxt->buffer.byteIndex * 8) + numBitsInLastByte); } ASN1OCTET* encodeGetMsgPtr (OOCTXT* pctxt, int* pLength) { if (pLength) *pLength = getPERMsgLen (pctxt); return pctxt->buffer.data; } int encodeIdent (OOCTXT* pctxt, ASN1UINT ident) { ASN1UINT mask; int nshifts = 0, stat; if (ident !=0) { ASN1UINT lv; nshifts = getIdentByteCount (ident); while (nshifts > 0) { mask = ((ASN1UINT)0x7f) << (7 * (nshifts - 1)); nshifts--; lv = (ASN1UINT)((ident & mask) >> (nshifts * 7)); if (nshifts != 0) { lv |= 0x80; } if ((stat = encodeBits (pctxt, lv, 8)) != ASN_OK) return LOG_ASN1ERR (pctxt, stat); } } else { /* encode a single zero byte */ if ((stat = encodeBits (pctxt, 0, 8)) != ASN_OK) return LOG_ASN1ERR (pctxt, stat); } return ASN_OK; } int encodeLength (OOCTXT* pctxt, ASN1UINT value) { ASN1BOOL extendable; Asn1SizeCnst* pSize = checkSize (pctxt->pSizeConstraint, value, &extendable); ASN1UINT lower = (pSize) ? pSize->lower : 0; ASN1UINT upper = (pSize) ? pSize->upper : ASN1UINT_MAX; int enclen, stat; /* If size constraints exist and the given length did not fall */ /* within the range of any of them, signal constraint violation */ /* error.. */ if (pctxt->pSizeConstraint && !pSize) return LOG_ASN1ERR (pctxt, ASN_E_CONSVIO); /* Reset the size constraint in the context block structure */ pctxt->pSizeConstraint = 0; /* If size constraint is present and extendable, encode extension */ /* bit.. */ if (extendable) { stat = (pSize) ? encodeBit (pctxt, pSize->extended) : encodeBit (pctxt, 1); if (stat != ASN_OK) return (stat); } /* If upper limit is less than 64k, constrained case */ if (upper < 65536) { stat = (lower == upper) ? ASN_OK : encodeConsWholeNumber (pctxt, value - lower, upper - lower + 1); enclen = (stat == ASN_OK) ? value : stat; } else { /* unconstrained case or Constrained with upper bound >= 64K*/ enclen = encodeUnconsLength (pctxt, value); } return enclen; } int encodeObjectIdentifier (OOCTXT* pctxt, ASN1OBJID* pvalue) { int len, stat; ASN1UINT temp; register int numids, i; /* Calculate length in bytes and encode */ len = 1; /* 1st 2 arcs require 1 byte */ numids = pvalue->numids; for (i = 2; i < numids; i++) { len += getIdentByteCount (pvalue->subid[i]); } /* PER encode length */ if ((stat = encodeLength (pctxt, (ASN1UINT)len)) < 0) { return LOG_ASN1ERR (pctxt, stat); } /* Validate given object ID by applying ASN.1 rules */ if (0 == pvalue) return LOG_ASN1ERR (pctxt, ASN_E_INVOBJID); if (numids < 2) return LOG_ASN1ERR (pctxt, ASN_E_INVOBJID); if (pvalue->subid[0] > 2) return LOG_ASN1ERR (pctxt, ASN_E_INVOBJID); if (pvalue->subid[0] != 2 && pvalue->subid[1] > 39) return LOG_ASN1ERR (pctxt, ASN_E_INVOBJID); /* Passed checks, encode object identifier */ /* Munge first two sub ID's and encode */ temp = ((pvalue->subid[0] * 40) + pvalue->subid[1]); if ((stat = encodeIdent (pctxt, temp)) != ASN_OK) return LOG_ASN1ERR (pctxt, stat); /* Encode the remainder of the OID value */ for (i = 2; i < numids; i++) { if ((stat = encodeIdent (pctxt, pvalue->subid[i])) != ASN_OK) return LOG_ASN1ERR (pctxt, stat); } return ASN_OK; } int encodebitsFromOctet (OOCTXT* pctxt, ASN1OCTET value, ASN1UINT nbits) { int lshift = pctxt->buffer.bitOffset; int rshift = 8 - pctxt->buffer.bitOffset; int stat = ASN_OK; ASN1OCTET mask; if (nbits == 0) return ASN_OK; /* Mask off unused bits from the end of the value */ if (nbits < 8) { switch (nbits) { case 1: mask = 0x80; break; case 2: mask = 0xC0; break; case 3: mask = 0xE0; break; case 4: mask = 0xF0; break; case 5: mask = 0xF8; break; case 6: mask = 0xFC; break; case 7: mask = 0xFE; break; default:; } value &= mask; } /* If we are on a byte boundary, we can do a direct assignment */ if (pctxt->buffer.bitOffset == 8) { pctxt->buffer.data[pctxt->buffer.byteIndex] = value; if (nbits == 8) { pctxt->buffer.byteIndex++; pctxt->buffer.data[pctxt->buffer.byteIndex] = 0; } else pctxt->buffer.bitOffset -= nbits; } /* Otherwise, need to set some bits in the first octet and */ /* possibly some bits in the following octet.. */ else { pctxt->buffer.data[pctxt->buffer.byteIndex] |= (ASN1OCTET)(value >> rshift); pctxt->buffer.bitOffset -= nbits; if (pctxt->buffer.bitOffset < 0) { pctxt->buffer.byteIndex++; pctxt->buffer.data[pctxt->buffer.byteIndex] = (ASN1OCTET)(value << lshift); pctxt->buffer.bitOffset += 8; } } return stat; } int encodeOctets (OOCTXT* pctxt, const ASN1OCTET* pvalue, ASN1UINT nbits) { int i = 0, stat; int numFullOcts = nbits / 8; if (nbits == 0) return 0; /* Check buffer space and allocate more memory if necessary */ stat = encodeCheckBuffer (pctxt, numFullOcts + 1); if (stat != ASN_OK) return LOG_ASN1ERR (pctxt, stat); if (numFullOcts > 0) { /* If the current bit offset is 8 (i.e. we don't have a */ /* byte started), can copy the string directly to the */ /* encode buffer.. */ if (pctxt->buffer.bitOffset == 8) { memcpy (&pctxt->buffer.data[pctxt->buffer.byteIndex], pvalue, numFullOcts); pctxt->buffer.byteIndex += numFullOcts; pctxt->buffer.data[pctxt->buffer.byteIndex] = 0; i = numFullOcts; } /* Else, copy bits */ else { for (i = 0; i < numFullOcts; i++) { stat = encodeBitsFromOctet (pctxt, pvalue[i], 8); if (stat != ASN_OK) return stat; } } } /* Move remaining bits from the last octet to the output buffer */ if (nbits % 8 != 0) { stat = encodeBitsFromOctet (pctxt, pvalue[i], nbits % 8); } return stat; } int encodeOctetString (OOCTXT* pctxt, ASN1UINT numocts, const ASN1OCTET* data) { int enclen, octidx = 0, stat; Asn1SizeCnst* pSizeList = pctxt->pSizeConstraint; for (;;) { if ((enclen = encodeLength (pctxt, numocts)) < 0) { return LOG_ASN1ERR (pctxt, enclen); } if (enclen > 0) { ASN1BOOL doAlign; stat = bitAndOctetStringAlignmentTest (pSizeList, numocts, FALSE, &doAlign); if (stat != ASN_OK) return LOG_ASN1ERR (pctxt, stat); if (doAlign) { stat = encodeByteAlign (pctxt); if (stat != ASN_OK) return LOG_ASN1ERR (pctxt, stat); } stat = encodeOctets (pctxt, &data[octidx], enclen * 8); if (stat != ASN_OK) return LOG_ASN1ERR (pctxt, stat); } if (enclen < (int)numocts) { numocts -= enclen; octidx += enclen; } else break; } return ASN_OK; } int encodeOpenType (OOCTXT* pctxt, ASN1UINT numocts, const ASN1OCTET* data) { int enclen, octidx = 0, stat; ASN1OCTET zeroByte = 0x00; ASN1OpenType openType; /* If open type contains length zero, add a single zero byte (10.1) */ if (numocts == 0) { openType.numocts = 1; openType.data = &zeroByte; } else { openType.numocts = numocts; openType.data = data; } /* Encode the open type */ for (;;) { if ((enclen = encodeLength (pctxt, openType.numocts)) < 0) { return LOG_ASN1ERR (pctxt, enclen); } stat = encodeByteAlign (pctxt); if (stat != ASN_OK) return LOG_ASN1ERR (pctxt, stat); stat = encodeOctets (pctxt, &openType.data[octidx], enclen * 8); if (stat != ASN_OK) return LOG_ASN1ERR (pctxt, stat); if (enclen < (int)openType.numocts) { openType.numocts -= enclen; octidx += enclen; } else break; } return ASN_OK; } int encodeOpenTypeExt (OOCTXT* pctxt, DList* pElemList) { DListNode* pnode; ASN1OpenType* pOpenType; int stat; if (0 != pElemList) { pnode = pElemList->head; while (0 != pnode) { if (0 != pnode->data) { pOpenType = (ASN1OpenType*)pnode->data; if (pOpenType->numocts > 0) { stat = encodeByteAlign (pctxt); if (stat != ASN_OK) return LOG_ASN1ERR (pctxt, stat); stat = encodeOpenType (pctxt, pOpenType->numocts, pOpenType->data); if (stat != ASN_OK) return LOG_ASN1ERR (pctxt, stat); } } pnode = pnode->next; } } return ASN_OK; } int encodeOpenTypeExtBits (OOCTXT* pctxt, DList* pElemList) { DListNode* pnode; int stat; if (0 != pElemList) { pnode = pElemList->head; while (0 != pnode) { stat = encodeBit (pctxt, (ASN1BOOL)(0 != pnode->data)); if (stat != ASN_OK) return LOG_ASN1ERR (pctxt, stat); pnode = pnode->next; } } return ASN_OK; } int encodeSemiConsInteger (OOCTXT* pctxt, ASN1INT value, ASN1INT lower) { int nbytes, stat; int shift = ((sizeof(value) - 1) * 8) - 1; ASN1UINT tempValue; if (lower > ASN1INT_MIN) value -= lower; /* Calculate signed number value length */ for ( ; shift > 0; shift -= 8) { tempValue = (value >> shift) & 0x1ff; if (tempValue == 0 || tempValue == 0x1ff) continue; else break; } nbytes = (shift + 9) / 8; /* Encode length */ if ((stat = encodeLength (pctxt, nbytes)) < 0) { return stat; } if ((stat = encodeByteAlign (pctxt)) != ASN_OK) return stat; /* Encode signed value */ stat = encode2sCompBinInt (pctxt, value); return stat; } int encodeSemiConsUnsigned (OOCTXT* pctxt, ASN1UINT value, ASN1UINT lower) { int nbytes, stat; int shift = ((sizeof(value) - 1) * 8) - 1; ASN1UINT mask = 1UL << ((sizeof(value) * 8) - 1); ASN1UINT tempValue; value -= lower; /* Calculate unsigned number value length */ for ( ; shift > 0; shift -= 8) { tempValue = (value >> shift) & 0x1ff; if (tempValue == 0) continue; else break; } nbytes = (shift + 9) / 8; /* If MS bit in unsigned number is set, add an extra zero byte */ if ((value & mask) != 0) nbytes++; /* Encode length */ if ((stat = encodeLength (pctxt, nbytes)) < 0) { return stat; } if ((stat = encodeByteAlign (pctxt)) != ASN_OK) return stat; /* Encode additional zero byte if necessary */ if (nbytes > sizeof(value)) { stat = encodebitsFromOctet (pctxt, 0, 8); if (stat != ASN_OK) return (stat); } /* Encode unsigned value */ stat = encodeNonNegBinInt (pctxt, value); return stat; } int encodeSmallNonNegWholeNumber (OOCTXT* pctxt, ASN1UINT value) { int stat; if (value < 64) { stat = encodeBits (pctxt, value, 7); } else { ASN1UINT len; /* Encode a one-byte length determinant value */ if (value < 256) len = 1; else if (value < 65536) len = 2; else if (value < 0x1000000) len = 3; else len = 4; stat = encodeBits (pctxt, len, 8); /* Byte-align and encode the value */ if (stat == ASN_OK) { if ((stat = encodeByteAlign (pctxt)) == ASN_OK) { stat = encodeBits (pctxt, value, len*8); } } } return stat; } int encodeVarWidthCharString (OOCTXT* pctxt, const char* value) { int stat; ASN1UINT len = strlen (value); /* note: need to save size constraint for use in alignCharStr */ /* because it will be cleared in encodeLength from the context.. */ Asn1SizeCnst* psize = pctxt->pSizeConstraint; /* Encode length */ stat = encodeLength (pctxt, len); if (stat < 0) return LOG_ASN1ERR (pctxt, stat); /* Byte align */ if (alignCharStr (pctxt, len, 8, psize)) { stat = encodeByteAlign (pctxt); if (stat != ASN_OK) return LOG_ASN1ERR (pctxt, stat); } /* Encode data */ stat = encodeOctets (pctxt, (const ASN1OCTET*)value, len * 8); if (stat != ASN_OK) return LOG_ASN1ERR (pctxt, stat); return ASN_OK; } static int encode16BitConstrainedString (OOCTXT* pctxt, Asn116BitCharString value, Asn116BitCharSet* pCharSet) { ASN1UINT i, pos; ASN1UINT nbits = pCharSet->alignedBits; int stat; /* Encode length */ stat = encodeLength (pctxt, value.nchars); if (stat < 0) return LOG_ASN1ERR (pctxt, stat); /* Byte align */ stat = encodeByteAlign (pctxt); if (stat != ASN_OK) return LOG_ASN1ERR (pctxt, stat); /* Encode data */ for (i = 0; i < value.nchars; i++) { if (pCharSet->charSet.data == 0) { stat = encodeBits (pctxt, value.data[i] - pCharSet->firstChar, nbits); if (stat != ASN_OK) return LOG_ASN1ERR (pctxt, stat); } else { for (pos = 0; pos < pCharSet->charSet.nchars; pos++) { if (value.data[i] == pCharSet->charSet.data[pos]) { stat = encodeBits (pctxt, pos, nbits); if (stat != ASN_OK) return LOG_ASN1ERR (pctxt, stat); break; } } } } return stat; } int encode2sCompBinInt (OOCTXT* pctxt, ASN1INT value) { /* 10.4.6 A minimum octet 2's-complement-binary-integer encoding */ /* of the whole number has a field width that is a multiple of 8 */ /* bits and also satisifies the condition that the leading 9 bits */ /* field shall not be all zeros and shall not be all ones. */ /* first encode integer value into a local buffer */ ASN1OCTET lbuf[8], lb; ASN1INT i = sizeof(lbuf), temp = value; memset (lbuf, 0, sizeof(lbuf)); do { lb = temp % 256; temp /= 256; if (temp < 0 && lb != 0) temp--; /* two's complement adjustment */ lbuf[--i] = lb; } while (temp != 0 && temp != -1); /* If the value is positive and bit 8 of the leading byte is set, */ /* copy a zero byte to the contents to signal a positive number.. */ if (value > 0 && (lb & 0x80) != 0) { i--; } /* If the value is negative and bit 8 of the leading byte is clear, */ /* copy a -1 byte (0xFF) to the contents to signal a negative */ /* number.. */ else if (value < 0 && ((lb & 0x80) == 0)) { lbuf[--i] = 0xff; } /* Add the data to the encode buffer */ return encodeOctets (pctxt, &lbuf[i], (sizeof(lbuf) - i) * 8); } static int encodeNonNegBinInt (OOCTXT* pctxt, ASN1UINT value) { /* 10.3.6 A minimum octet non-negative binary integer encoding of */ /* the whole number (which does not predetermine the number of */ /* octets to be used for the encoding) has a field which is a */ /* multiple of 8 bits and also satisifies the condition that the */ /* leading eight bits of the field shall not be zero unless the */ /* field is precisely 8 bits long. */ ASN1UINT bitcnt = (value == 0) ? 1 : getUIntBitCount (value); /* round-up to nearest 8-bit boundary */ bitcnt = (bitcnt + 7) & (~7); /* encode bits */ return encodeBits (pctxt, value, bitcnt); } static int encodeUnconsLength (OOCTXT* pctxt, ASN1UINT value) { int enclen, stat; stat = encodeByteAlign (pctxt); if (stat != ASN_OK) return LOG_ASN1ERR (pctxt, stat); /* 1 octet case */ if (value < 128) { stat = encodeBits (pctxt, value, 8); enclen = (stat == ASN_OK) ? value : stat; } /* 2 octet case */ else if (value < 16384) { if ((stat = encodeBit (pctxt, 1)) == ASN_OK) stat = encodeBits (pctxt, value, 15); enclen = (stat == ASN_OK) ? value : stat; } /* fragmentation case */ else { int multiplier = ASN1MIN (value/16384, 4); encodeBit (pctxt, 1); /* set bit 8 of first octet */ encodeBit (pctxt, 1); /* set bit 7 of first octet */ stat = encodeBits (pctxt, multiplier, 6); enclen = (stat == ASN_OK) ? 16384 * multiplier : stat; } return enclen; } static int getIdentByteCount (ASN1UINT ident) { if (ident < (1u << 7)) { /* 7 */ return 1; } else if (ident < (1u << 14)) { /* 14 */ return 2; } else if (ident < (1u << 21)) { /* 21 */ return 3; } else if (ident < (1u << 28)) { /* 28 */ return 4; } return 5; } /*Added by Karl on 2004-11-24 for G72x below */ //Global data def int gnTarget_Memory_Size = 2; //2m int gnBits = 4; int gnPCM_Gain = 0; //1x int gnWait_Length = 40; //40*128ms = 5s //LPCSTR gpOutput_File_Name = NULL; int gbBinary = TRUE; int gnOutBuffCounter = 0; int pack_output(unsigned code, int bits, unsigned char *pDataTrack) { static int wOutBuff = 0; static int nOutBits = 0; unsigned char bOutByte; unsigned char bLeft = 0; /*Modified by Joe and karl on 2005-01-17 below*/ wOutBuff <<= bits; wOutBuff |= code; nOutBits += bits; if (nOutBits >= 8) { bLeft = wOutBuff & 0xff; bLeft <<= 8- (nOutBits - 8); bLeft >>= 8- (nOutBits - 8); bOutByte = wOutBuff >> (nOutBits - 8);//È¡¸ß8λ nOutBits -= 8; //wOutBuff >>= 8; pDataTrack[gnOutBuffCounter] = bOutByte; wOutBuff = bLeft; gnOutBuffCounter++; } /*Modified by Joe and karl on 2005-01-17 above*/ return (nOutBits > 0); } static short power2[15] = {1, 2, 4, 8, 0x10, 0x20, 0x40, 0x80, 0x100, 0x200, 0x400, 0x800, 0x1000, 0x2000, 0x4000}; /* * quan() * * quantizes the input val against the table of size short integers. * It returns i if table[i - 1] <= val < table[i]. * * Using linear search for simple coding. */ static int quan( int val, short *table, int size) { int i; for (i = 0; i < size; i++) if (val < *table++) break; return (i); } /* * fmult() * * returns the integer product of the 14-bit integer "an" and * "floating point" representation (4-bit exponent, 6-bit mantessa) "srn". */ static int fmult( int an, int srn) { short anmag, anexp, anmant; short wanexp, wanmant; short retval; anmag = (an > 0) ? an : ((-an) & 0x1FFF); anexp = quan(anmag, power2, 15) - 6; anmant = (anmag == 0) ? 32 : (anexp >= 0) ? anmag >> anexp : anmag << -anexp; wanexp = anexp + ((srn >> 6) & 0xF) - 13; wanmant = (anmant * (srn & 077) + 0x30) >> 4; retval = (wanexp >= 0) ? ((wanmant << wanexp) & 0x7FFF) : (wanmant >> -wanexp); return (((an ^ srn) < 0) ? -retval : retval); } /* * g72x_init_state() * * This routine initializes and/or resets the g72x_state structure * pointed to by 'state_ptr'. * All the initial state values are specified in the CCITT G.721 document. */ void g72x_init_state( struct g72x_state *state_ptr) { int cnta; state_ptr->yl = 34816; state_ptr->yu = 544; state_ptr->dms = 0; state_ptr->dml = 0; state_ptr->ap = 0; for (cnta = 0; cnta < 2; cnta++) { state_ptr->a[cnta] = 0; state_ptr->pk[cnta] = 0; state_ptr->sr[cnta] = 32; } for (cnta = 0; cnta < 6; cnta++) { state_ptr->b[cnta] = 0; state_ptr->dq[cnta] = 32; } state_ptr->td = 0; } /* * predictor_zero() * * computes the estimated signal from 6-zero predictor. * */ int predictor_zero( struct g72x_state *state_ptr) { int i; int sezi; sezi = fmult(state_ptr->b[0] >> 2, state_ptr->dq[0]); for (i = 1; i < 6; i++) /* ACCUM */ sezi += fmult(state_ptr->b[i] >> 2, state_ptr->dq[i]); return (sezi); } /* * predictor_pole() * * computes the estimated signal from 2-pole predictor. * */ int predictor_pole( struct g72x_state *state_ptr) { return (fmult(state_ptr->a[1] >> 2, state_ptr->sr[1]) + fmult(state_ptr->a[0] >> 2, state_ptr->sr[0])); } /* * step_size() * * computes the quantization step size of the adaptive quantizer. * */ int step_size( struct g72x_state *state_ptr) { int y; int dif; int al; if (state_ptr->ap >= 256) return (state_ptr->yu); else { y = state_ptr->yl >> 6; dif = state_ptr->yu - y; al = state_ptr->ap >> 2; if (dif > 0) y += (dif * al) >> 6; else if (dif < 0) y += (dif * al + 0x3F) >> 6; return (y); } } /* * quantize() * * Given a raw sample, 'd', of the difference signal and a * quantization step size scale factor, 'y', this routine returns the * ADPCM codeword to which that sample gets quantized. The step * size scale factor division operation is done in the log base 2 domain * as a subtraction. */ int quantize( int d, /* Raw difference signal sample */ int y, /* Step size multiplier */ short *table, /* quantization table */ int size) /* table size of short integers */ { short dqm; /* Magnitude of 'd' */ short exp; /* Integer part of base 2 log of 'd' */ short mant; /* Fractional part of base 2 log */ short dl; /* Log of magnitude of 'd' */ short dln; /* Step size scale factor normalized log */ int i; /* * LOG * * Compute base 2 log of 'd', and store in 'dl'. */ dqm = abs(d); exp = quan(dqm >> 1, power2, 15); mant = ((dqm << 7) >> exp) & 0x7F; /* Fractional portion. */ dl = (exp << 7) + mant; /* * SUBTB * * "Divide" by step size multiplier. */ dln = dl - (y >> 2); /* * QUAN * * Obtain codword i for 'd'. */ i = quan(dln, table, size); if (d < 0) /* take 1's complement of i */ return ((size << 1) + 1 - i); else if (i == 0) /* take 1's complement of 0 */ return ((size << 1) + 1); /* new in 1988 */ else return (i); } /* * reconstruct() * * Returns reconstructed difference signal 'dq' obtained from * codeword 'i' and quantization step size scale factor 'y'. * Multiplication is performed in log base 2 domain as addition. */ int reconstruct( int sign, /* 0 for non-negative value */ int dqln, /* G.72x codeword */ int y) /* Step size multiplier */ { short dql; /* Log of 'dq' magnitude */ short dex; /* Integer part of log */ short dqt; short dq; /* Reconstructed difference signal sample */ dql = dqln + (y >> 2); /* ADDA */ if (dql < 0) { return ((sign) ? -0x8000 : 0); } else { /* ANTILOG */ dex = (dql >> 7) & 15; dqt = 128 + (dql & 127); dq = (dqt << 7) >> (14 - dex); return ((sign) ? (dq - 0x8000) : dq); } } /* * update() * * updates the state variables for each output code */ void update( int code_size, /* distinguish 723_40 with others */ int y, /* quantizer step size */ int wi, /* scale factor multiplier */ int fi, /* for long/short term energies */ int dq, /* quantized prediction difference */ int sr, /* reconstructed signal */ int dqsez, /* difference from 2-pole predictor */ struct g72x_state *state_ptr) /* coder state pointer */ { int cnt; short mag, exp; /* Adaptive predictor, FLOAT A */ short a2p; /* LIMC */ short a1ul; /* UPA1 */ short pks1; /* UPA2 */ short fa1; char tr; /* tone/transition detector */ short ylint, thr2, dqthr; short ylfrac, thr1; short pk0; pk0 = (dqsez < 0) ? 1 : 0; /* needed in updating predictor poles */ mag = dq & 0x7FFF; /* prediction difference magnitude */ /* TRANS */ ylint = state_ptr->yl >> 15; /* exponent part of yl */ ylfrac = (state_ptr->yl >> 10) & 0x1F; /* fractional part of yl */ thr1 = (32 + ylfrac) << ylint; /* threshold */ thr2 = (ylint > 9) ? 31 << 10 : thr1; /* limit thr2 to 31 << 10 */ dqthr = (thr2 + (thr2 >> 1)) >> 1; /* dqthr = 0.75 * thr2 */ if (state_ptr->td == 0) /* signal supposed voice */ tr = 0; else if (mag <= dqthr) /* supposed data, but small mag */ tr = 0; /* treated as voice */ else /* signal is data (modem) */ tr = 1; /* * Quantizer scale factor adaptation. */ /* FUNCTW & FILTD & DELAY */ /* update non-steady state step size multiplier */ state_ptr->yu = y + ((wi - y) >> 5); /* LIMB */ if (state_ptr->yu < 544) /* 544 <= yu <= 5120 */ state_ptr->yu = 544; else if (state_ptr->yu > 5120) state_ptr->yu = 5120; /* FILTE & DELAY */ /* update steady state step size multiplier */ state_ptr->yl += state_ptr->yu + ((-state_ptr->yl) >> 6); /* * Adaptive predictor coefficients. */ if (tr == 1) { /* reset a's and b's for modem signal */ state_ptr->a[0] = 0; state_ptr->a[1] = 0; state_ptr->b[0] = 0; state_ptr->b[1] = 0; state_ptr->b[2] = 0; state_ptr->b[3] = 0; state_ptr->b[4] = 0; state_ptr->b[5] = 0; } else { /* update a's and b's */ pks1 = pk0 ^ state_ptr->pk[0]; /* UPA2 */ /* update predictor pole a[1] */ a2p = state_ptr->a[1] - (state_ptr->a[1] >> 7); if (dqsez != 0) { fa1 = (pks1) ? state_ptr->a[0] : -state_ptr->a[0]; if (fa1 < -8191) /* a2p = function of fa1 */ a2p -= 0x100; else if (fa1 > 8191) a2p += 0xFF; else a2p += fa1 >> 5; if (pk0 ^ state_ptr->pk[1]) /* LIMC */ if (a2p <= -12160) a2p = -12288; else if (a2p >= 12416) a2p = 12288; else a2p -= 0x80; else if (a2p <= -12416) a2p = -12288; else if (a2p >= 12160) a2p = 12288; else a2p += 0x80; } /* TRIGB & DELAY */ state_ptr->a[1] = a2p; /* UPA1 */ /* update predictor pole a[0] */ state_ptr->a[0] -= state_ptr->a[0] >> 8; if (dqsez != 0) if (pks1 == 0) state_ptr->a[0] += 192; else state_ptr->a[0] -= 192; /* LIMD */ a1ul = 15360 - a2p; if (state_ptr->a[0] < -a1ul) state_ptr->a[0] = -a1ul; else if (state_ptr->a[0] > a1ul) state_ptr->a[0] = a1ul; /* UPB : update predictor zeros b[6] */ for (cnt = 0; cnt < 6; cnt++) { if (code_size == 5) /* for 40Kbps G.723 */ state_ptr->b[cnt] -= state_ptr->b[cnt] >> 9; else /* for G.721 and 24Kbps G.723 */ state_ptr->b[cnt] -= state_ptr->b[cnt] >> 8; if (dq & 0x7FFF) { /* XOR */ if ((dq ^ state_ptr->dq[cnt]) >= 0) state_ptr->b[cnt] += 128; else state_ptr->b[cnt] -= 128; } } } for (cnt = 5; cnt > 0; cnt--) state_ptr->dq[cnt] = state_ptr->dq[cnt-1]; /* FLOAT A : convert dq[0] to 4-bit exp, 6-bit mantissa f.p. */ if (mag == 0) { state_ptr->dq[0] = (dq >= 0) ? 0x20 : 0xFC20; } else { exp = quan(mag, power2, 15); state_ptr->dq[0] = (dq >= 0) ? (exp << 6) + ((mag << 6) >> exp) : (exp << 6) + ((mag << 6) >> exp) - 0x400; } state_ptr->sr[1] = state_ptr->sr[0]; /* FLOAT B : convert sr to 4-bit exp., 6-bit mantissa f.p. */ if (sr == 0) { state_ptr->sr[0] = 0x20; } else if (sr > 0) { exp = quan(sr, power2, 15); state_ptr->sr[0] = (exp << 6) + ((sr << 6) >> exp); } else if (sr > -32768) { mag = -sr; exp = quan(mag, power2, 15); state_ptr->sr[0] = (exp << 6) + ((mag << 6) >> exp) - 0x400; } else state_ptr->sr[0] = 0xFC20; /* DELAY A */ state_ptr->pk[1] = state_ptr->pk[0]; state_ptr->pk[0] = pk0; /* TONE */ if (tr == 1) /* this sample has been treated as data */ state_ptr->td = 0; /* next one will be treated as voice */ else if (a2p < -11776) /* small sample-to-sample correlation */ state_ptr->td = 1; /* signal may be data */ else /* signal is voice */ state_ptr->td = 0; /* * Adaptation speed control. */ state_ptr->dms += (fi - state_ptr->dms) >> 5; /* FILTA */ state_ptr->dml += (((fi << 2) - state_ptr->dml) >> 7); /* FILTB */ if (tr == 1) state_ptr->ap = 256; else if (y < 1536) /* SUBTC */ state_ptr->ap += (0x200 - state_ptr->ap) >> 4; else if (state_ptr->td == 1) state_ptr->ap += (0x200 - state_ptr->ap) >> 4; else if (abs((state_ptr->dms << 2) - state_ptr->dml) >= (state_ptr->dml >> 3)) state_ptr->ap += (0x200 - state_ptr->ap) >> 4; else state_ptr->ap += (-state_ptr->ap) >> 4; } /* * tandem_adjust(sr, se, y, i, sign) * * At the end of ADPCM decoding, it simulates an encoder which may be receiving * the output of this decoder as a tandem process. If the output of the * simulated encoder differs from the input to this decoder, the decoder output * is adjusted by one level of A-law or u-law codes. * * Input: * sr decoder output linear PCM sample, * se predictor estimate sample, * y quantizer step size, * i decoder input code, * sign sign bit of code i * * Return: * adjusted A-law or u-law compressed sample. */ int tandem_adjust_alaw( int sr, /* decoder output linear PCM sample */ int se, /* predictor estimate sample */ int y, /* quantizer step size */ int i, /* decoder input code */ int sign, short *qtab) { unsigned char sp; /* A-law compressed 8-bit code */ short dx; /* prediction error */ char id; /* quantized prediction error */ int sd; /* adjusted A-law decoded sample value */ int im; /* biased magnitude of i */ int imx; /* biased magnitude of id */ if (sr <= -32768) sr = -1; sp = linear2alaw((sr >> 1) << 3); /* short to A-law compression */ dx = (alaw2linear(sp) >> 2) - se; /* 16-bit prediction error */ id = quantize(dx, y, qtab, sign - 1); if (id == i) { /* no adjustment on sp */ return (sp); } else { /* sp adjustment needed */ /* ADPCM codes : 8, 9, ... F, 0, 1, ... , 6, 7 */ im = i ^ sign; /* 2's complement to biased unsigned */ imx = id ^ sign; if (imx > im) { /* sp adjusted to next lower value */ if (sp & 0x80) { sd = (sp == 0xD5) ? 0x55 : ((sp ^ 0x55) - 1) ^ 0x55; } else { sd = (sp == 0x2A) ? 0x2A : ((sp ^ 0x55) + 1) ^ 0x55; } } else { /* sp adjusted to next higher value */ if (sp & 0x80) sd = (sp == 0xAA) ? 0xAA : ((sp ^ 0x55) + 1) ^ 0x55; else sd = (sp == 0x55) ? 0xD5 : ((sp ^ 0x55) - 1) ^ 0x55; } return (sd); } } int tandem_adjust_ulaw( int sr, /* decoder output linear PCM sample */ int se, /* predictor estimate sample */ int y, /* quantizer step size */ int i, /* decoder input code */ int sign, short *qtab) { unsigned char sp; /* u-law compressed 8-bit code */ short dx; /* prediction error */ char id; /* quantized prediction error */ int sd; /* adjusted u-law decoded sample value */ int im; /* biased magnitude of i */ int imx; /* biased magnitude of id */ if (sr <= -32768) sr = 0; sp = linear2ulaw(sr << 2); /* short to u-law compression */ dx = (ulaw2linear(sp) >> 2) - se; /* 16-bit prediction error */ id = quantize(dx, y, qtab, sign - 1); if (id == i) { return (sp); } else { /* ADPCM codes : 8, 9, ... F, 0, 1, ... , 6, 7 */ im = i ^ sign; /* 2's complement to biased unsigned */ imx = id ^ sign; if (imx > im) { /* sp adjusted to next lower value */ if (sp & 0x80) sd = (sp == 0xFF) ? 0x7E : sp + 1; else sd = (sp == 0) ? 0 : sp - 1; } else { /* sp adjusted to next higher value */ if (sp & 0x80) sd = (sp == 0x80) ? 0x80 : sp - 1; else sd = (sp == 0x7F) ? 0xFE : sp + 1; } return (sd); } } static short qtab_721[7] = {-124, 80, 178, 246, 300, 349, 400}; /* * Maps G.721 code word to reconstructed scale factor normalized log * magnitude values. */ static short _dqlntab[16] = {-2048, 4, 135, 213, 273, 323, 373, 425, 425, 373, 323, 273, 213, 135, 4, -2048}; /* Maps G.721 code word to log of scale factor multiplier. */ static short _witab[16] = {-12, 18, 41, 64, 112, 198, 355, 1122, 1122, 355, 198, 112, 64, 41, 18, -12}; /* * Maps G.721 code words to a set of values whose long and short * term averages are computed and then compared to give an indication * how stationary (steady state) the signal is. */ static short _fitab[16] = {0, 0, 0, 0x200, 0x200, 0x200, 0x600, 0xE00, 0xE00, 0x600, 0x200, 0x200, 0x200, 0, 0, 0}; /* * g721_encoder() * * Encodes the input vale of linear PCM, A-law or u-law data sl and returns * the resulting code. -1 is returned for unknown input coding value. */ int g721_encoder( int sl, int in_coding, struct g72x_state *state_ptr) { short sezi, se, sez; /* ACCUM */ short d; /* SUBTA */ short sr; /* ADDB */ short y; /* MIX */ short dqsez; /* ADDC */ short dq, i; switch (in_coding) { /* linearize input sample to 14-bit PCM */ case AUDIO_ENCODING_ALAW: sl = alaw2linear(sl) >> 2; break; case AUDIO_ENCODING_ULAW: sl = ulaw2linear(sl) >> 2; break; case AUDIO_ENCODING_LINEAR: sl >>= 2; /* 14-bit dynamic range */ break; default: return (-1); } sezi = predictor_zero(state_ptr); sez = sezi >> 1; se = (sezi + predictor_pole(state_ptr)) >> 1; /* estimated signal */ d = sl - se; /* estimation difference */ /* quantize the prediction difference */ y = step_size(state_ptr); /* quantizer step size */ i = quantize(d, y, qtab_721, 7); /* i = ADPCM code */ dq = reconstruct(i & 8, _dqlntab[i], y); /* quantized est diff */ sr = (dq < 0) ? se - (dq & 0x3FFF) : se + dq; /* reconst. signal */ dqsez = sr + sez - se; /* pole prediction diff. */ update(4, y, _witab[i] << 5, _fitab[i], dq, sr, dqsez, state_ptr); return (i); } /* * g721_decoder() * * Description: * * Decodes a 4-bit code of G.721 encoded data of i and * returns the resulting linear PCM, A-law or u-law value. * return -1 for unknown out_coding value. */ int g721_decoder( int i, int out_coding, struct g72x_state *state_ptr) { short sezi, sei, sez, se; /* ACCUM */ short y; /* MIX */ short sr; /* ADDB */ short dq; short dqsez; i &= 0x0f; /* mask to get proper bits */ sezi = predictor_zero(state_ptr); sez = sezi >> 1; sei = sezi + predictor_pole(state_ptr); se = sei >> 1; /* se = estimated signal */ y = step_size(state_ptr); /* dynamic quantizer step size */ dq = reconstruct(i & 0x08, _dqlntab[i], y); /* quantized diff. */ sr = (dq < 0) ? (se - (dq & 0x3FFF)) : se + dq; /* reconst. signal */ dqsez = sr - se + sez; /* pole prediction diff. */ update(4, y, _witab[i] << 5, _fitab[i], dq, sr, dqsez, state_ptr); switch (out_coding) { case AUDIO_ENCODING_ALAW: return (tandem_adjust_alaw(sr, se, y, i, 8, qtab_721)); case AUDIO_ENCODING_ULAW: return (tandem_adjust_ulaw(sr, se, y, i, 8, qtab_721)); case AUDIO_ENCODING_LINEAR: return (sr << 2); /* sr was 14-bit dynamic range */ default: return (-1); } } /*Added by Karl on 2004-11-24 for G72x above */